Search Results

Search found 23804 results on 953 pages for 'void pointer'.

Page 101/953 | < Previous Page | 97 98 99 100 101 102 103 104 105 106 107 108  | Next Page >

  • Is there a workaround for Linux mono's refusal to acknowledge that I have resized the columns of my

    - by fantius
    When I resize a column, it does not redraw the data with the updated alignment. I've tried Invalidating, Refreshing, and a few other things. Nothing has worked. Does anyone know a workaround? I have not tried this in mono for Windows. To see what I mean, drop this control on a form, and run it in mono for Linux: using System; using System.Collections.Generic; using System.Text; using System.Windows.Forms; using System.Drawing; class MyListView : ListView { private readonly List<ListViewItem> items_ = new List<ListViewItem>(); public MyListView() { VirtualMode = true; Columns.Add("Col 1"); Columns.Add("Col 2"); Columns.Add("Col 3"); Add(new ListViewItem(new[] { "a", "b", "c" })); Add(new ListViewItem(new[] { "a", "b", "c" })); Add(new ListViewItem(new[] { "a", "b", "c" })); Add(new ListViewItem(new[] { "a", "b", "c" })); Add(new ListViewItem(new[] { "a", "b", "c" })); } protected override void OnRetrieveVirtualItem(RetrieveVirtualItemEventArgs e) { e.Item = items_[e.ItemIndex]; base.OnRetrieveVirtualItem(e); } public void Add(ListViewItem item) { items_.Add(item); VirtualListSize = items_.Count; } protected override void OnDrawColumnHeader(DrawListViewColumnHeaderEventArgs e) { e.DrawText(); base.OnDrawColumnHeader(e); } protected override void OnDrawSubItem(DrawListViewSubItemEventArgs e) { var text = ((ListViewItem.ListViewSubItem)e.SubItem).Text; using (var brush = new SolidBrush(e.SubItem.ForeColor)) { e.Graphics.DrawString(text, Font, brush, e.Bounds); } base.OnDrawSubItem(e); } protected override void OnColumnWidthChanged(ColumnWidthChangedEventArgs e) { base.OnColumnWidthChanged(e); Invalidate(true); // Nope, that didn't work Refresh(); // Nope, that didn't work } }

    Read the article

  • iOS TableView crash loading different data

    - by jollyr0ger
    Hi to all! I'm developing a simple iOS app where there is a table view with some categories (CategoryViewController). When clicking one of this category the view will be passed to a RecipesListController with another table view with recipes. This recipes are loaded from different plist based on the category clicked. The first time I click on a category, the recipes list is loaded and shown correctely. If i back to the category list and click any of the category (also the same again) the app crash. And I don't know how. The viewWillAppear is ececuted correctely but after crash. Can you help me? If you need the entire project I can zip it for you. Ok? Here is the code of the CategoryViewController.h #import <Foundation/Foundation.h> #import "RecipeRowViewController.h" @class RecipesListController; @interface CategoryViewController : UITableViewController { NSArray *recipeCategories; RecipesListController *childController; } @property (nonatomic, retain) NSArray *recipeCategories; @end The CategoryViewControoler.m #import "CategoryViewCotroller.h" #import "NavAppDelegate.h" #import "RecipesListController.h" @implementation CategoryViewController @synthesize recipeCategories; - (void)viewDidLoad { // Create the categories NSArray *array = [[NSArray alloc] initWithObjects:@"Antipasti", @"Focacce", @"Primi", @"Secondi", @"Contorni", @"Dolci", nil]; self.recipeCategories = array; [array release]; // Set background image UIImageView *bgImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sfondo_app.png"]]; [self.tableView setBackgroundView:bgImg]; [bgImg release]; [self.tableView reloadData]; [super viewDidLoad]; } - (void)viewDidUnload { self.recipeCategories = nil; // [childController release]; [super viewDidUnload]; } - (void)dealloc { [recipeCategories release]; // [childController release]; [super dealloc]; } #pragma mark - #pragma mark Table data source methods - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return [recipeCategories count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellId = @"RecipesCategoriesCellId"; // Try to reuse a cell or create a new one UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellId]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellId] autorelease]; } // Get the right value and assign to the cell NSUInteger row = [indexPath row]; NSString *rowString = [recipeCategories objectAtIndex:row]; cell.textLabel.text = rowString; cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; [rowString release]; return cell; } #pragma mark - #pragma mark Table view delegate methods - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { if (childController == nil) { childController = [[RecipesListController alloc] initWithStyle:UITableViewStyleGrouped]; } childController.title = @"Ricette"; childController.category = [indexPath row]; [self.navigationController pushViewController:childController animated:YES]; } @end The RecipesListController.h #import <Foundation/Foundation.h> #import "RecipeRowViewController.h" #define kRecipeArrayLink 0 #define kRecipeArrayDifficulty 1 #define kRecipeArrayFoodType 2 #define kRecipeAntipasti 0 #define kRecipeFocacce 1 #define kRecipePrimi 2 #define kRecipeSecondi 3 #define kRecipeContorni 4 #define kRecipeDolci 5 @class DisclosureDetailController; @interface RecipesListController : UITableViewController { NSInteger category; NSDictionary *recipesArray; NSArray *recipesNames; NSArray *recipesLinks; DisclosureDetailController *childController; } @property (nonatomic) NSInteger category; @property (nonatomic, retain) NSDictionary *recipesArray; @property (nonatomic, retain) NSArray *recipesNames; @property (nonatomic, retain) NSArray *recipesLinks; @end The RecipesListcontroller.m #import "RecipesListController.h" #import "NavAppDelegate.h" #import "DisclosureDetailController.h" @implementation RecipesListController @synthesize category, recipesArray, recipesNames, recipesLinks; - (void)viewDidLoad { // Set background image UIImageView *bgImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sfondo_app.png"]]; [self.tableView setBackgroundView:bgImg]; [bgImg release]; [self.tableView reloadData]; [super viewDidLoad]; } - (void)viewWillAppear:(BOOL)animated { if (self.recipesArray != nil) { // Release the arrays [self.recipesArray release]; [self.recipesNames release]; } // Load the dictionary NSString *path = nil; // Load a different dictionary, based on the category if (self.category == kRecipeAntipasti) { path = [[NSBundle mainBundle] pathForResource:@"recipes_antipasti" ofType:@"plist"]; } else if (self.category == kRecipeFocacce) { path = [[NSBundle mainBundle] pathForResource:@"recipes_focacce" ofType:@"plist"]; } else if (self.category == kRecipePrimi) { path = [[NSBundle mainBundle] pathForResource:@"recipes_primi" ofType:@"plist"]; } else if (self.category == kRecipeSecondi) { path = [[NSBundle mainBundle] pathForResource:@"recipes_secondi" ofType:@"plist"]; } else if (self.category == kRecipeContorni) { path = [[NSBundle mainBundle] pathForResource:@"recipes_contorni" ofType:@"plist"]; } else if (self.category == kRecipeDolci) { path = [[NSBundle mainBundle] pathForResource:@"recipes_dolci" ofType:@"plist"]; } NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:path]; self.recipesArray = dict; [dict release]; // Save recipes names NSArray *array = [[recipesArray allKeys] sortedArrayUsingSelector: @selector(compare:)]; self.recipesNames = array; [self.tableView reloadData]; [super viewWillAppear:animated]; } - (void)viewDidUnload { self.recipesArray = nil; self.recipesNames = nil; self.recipesLinks = nil; // [childController release]; [super viewDidUnload]; } - (void)dealloc { [recipesArray release]; [recipesNames release]; [recipesLinks release]; // [childController release]; [super dealloc]; } #pragma mark - #pragma mark Table data source methods - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return [recipesNames count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *RecipesListCellId = @"RecipesListCellId"; // Try to reuse a cell or create a new one UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:RecipesListCellId]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:RecipesListCellId] autorelease]; } // Get the right value and assign to the cell NSUInteger row = [indexPath row]; NSString *rowString = [recipesNames objectAtIndex:row]; cell.textLabel.text = rowString; cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; [rowString release]; return cell; } #pragma mark - #pragma mark Table view delegate methods - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { if (childController == nil) { childController = [[DisclosureDetailController alloc] initWithNibName:@"DisclosureDetail" bundle:nil]; } childController.title = @"Dettagli"; NSUInteger row = [indexPath row]; childController.recipeName = [recipesNames objectAtIndex:row]; NSArray *recipeRawArray = [recipesArray objectForKey:childController.recipeName]; childController.recipeLink = [recipeRawArray objectAtIndex:kRecipeArrayLink]; childController.recipeDifficulty = [recipeRawArray objectAtIndex:kRecipeArrayDifficulty]; [self.navigationController pushViewController:childController animated:YES]; } @end This is the crash log Program received signal: “EXC_BAD_ACCESS”. (gdb) bt #0 0x00f0da63 in objc_msgSend () #1 0x04b27ca0 in ?? () #2 0x00002665 in -[RecipesListController viewWillAppear:] (self=0x4b38a00, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67 #3 0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] () #4 0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] () #5 0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] () #6 0x04f49549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] () #7 0x0036b4a0 in -[UINavigationController pushViewController:animated:] () #8 0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b27ca0, _cmd=0x6d19e3, tableView=0x500c200, indexPath=0x4b2d650) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104 #9 0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] () #10 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] () #11 0x000337f6 in __NSFireDelayedPerform () #12 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ () #13 0x00d8e594 in __CFRunLoopDoTimer () #14 0x00ceacc9 in __CFRunLoopRun () #15 0x00cea240 in CFRunLoopRunSpecific () #16 0x00cea161 in CFRunLoopRunInMode () #17 0x016e0268 in GSEventRunModal () #18 0x016e032d in GSEventRun () #19 0x002c342e in UIApplicationMain () #20 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15 Another bt log: (gdb) bt #0 0x00cd76a1 in __CFBasicHashDeallocate () #1 0x00cc2bcb in _CFRelease () #2 0x00002dd6 in -[RecipesListController setRecipesArray:] (self=0x6834d50, _cmd=0x4293, _value=0x4e3bc70) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:16 #3 0x00002665 in -[RecipesListController viewWillAppear:] (self=0x6834d50, _cmd=0x6d81a2, animated=1 '\001') at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/RecipesListController.m:67 #4 0x00370c9a in -[UINavigationController _startTransition:fromViewController:toViewController:] () #5 0x0036b606 in -[UINavigationController _startDeferredTransitionIfNeeded] () #6 0x0037283e in -[UINavigationController pushViewController:transition:forceImmediate:] () #7 0x091ac549 in -[UINavigationControllerAccessibility(SafeCategory) pushViewController:transition:forceImmediate:] () #8 0x0036b4a0 in -[UINavigationController pushViewController:animated:] () #9 0x00003919 in -[CategoryViewController tableView:didSelectRowAtIndexPath:] (self=0x4b12970, _cmd=0x6d19e3, tableView=0x5014400, indexPath=0x4b2bd00) at /Users/claudiocanino/Documents/iOS/CottoMangiato/Classes/CategoryViewCotroller.m:104 #10 0x0032a794 in -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] () #11 0x00320d50 in -[UITableView _userSelectRowAtPendingSelectionIndexPath:] () #12 0x000337f6 in __NSFireDelayedPerform () #13 0x00d8cfe3 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ () #14 0x00d8e594 in __CFRunLoopDoTimer () #15 0x00ceacc9 in __CFRunLoopRun () #16 0x00cea240 in CFRunLoopRunSpecific () #17 0x00cea161 in CFRunLoopRunInMode () #18 0x016e0268 in GSEventRunModal () #19 0x016e032d in GSEventRun () #20 0x002c342e in UIApplicationMain () #21 0x00001c08 in main (argc=1, argv=0xbfffef58) at /Users/claudiocanino/Documents/iOS/CottoMangiato/main.m:15 Thanks

    Read the article

  • How can I make this client as a multithread client?

    - by Johanna
    Hi, I have read a lot about multithread client but for this one,I can not make it multithread! would you please help me? public class MainClient implements Runnable{ private static InformationClass info = new InformationClass(); private static Socket c; private static String text; public static String getText() { return text; } public static void setText(String text) { MainClient.text = text; } private static PrintWriter os; private static BufferedReader is; static boolean closed = false; /** * @param args the command line arguments */ public static void main(String[] args) { MainFrame farme = new MainFrame(); farme.setVisible(true); try { c = new Socket("localhost", 5050); os = new PrintWriter(c.getOutputStream(), true); is = new BufferedReader(new InputStreamReader(c.getInputStream())); } catch (UnknownHostException ex) { Logger.getLogger(MainClient.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(MainClient.class.getName()).log(Level.SEVERE, null, ex); } } public static void active() { String teXt = MainClient.getText(); System.out.println(teXt); os.println(teXt); try { String line = is.readLine(); System.out.println("Text received: " + line); os.flush(); is.close(); is.close(); c.close(); } catch (IOException ex) { Logger.getLogger(MainClient.class.getName()).log(Level.SEVERE, null, ex); } } } also active method will be called when the client write something on the text area and then clicks on the send button. 2) also i have a question that: in the other class I have this action performed for my send button,does it mean that client is multithread?? private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { new Thread(new Runnable() { @Override public void run() { // This gets run in a background thread String text = jTextArea1.getText(); jTextArea2.append(client.getCurrentName() + " : " + text + "\n"); MainClient.setText(client.getCurrentName() + " : " + text + "\n"); clear(); MainClient.active(); } }).start(); } Last EDIT: this is my active method: public static void active() { String teXt = MainClient.getText(); os.println(teXt); String line = is.readLine(); System.out.println("Text received: " + line); os.flush(); is.close(); is.close(); c.close(); }

    Read the article

  • 47 memory leaks. STL pointers.

    - by icelated
    I have a major amount of memory leaks. I know that the Sets have pointers and i cannot change that! I cannot change anything, but clean up the mess i have... I am creating memory with new in just about every function to add information to the sets. I have a Cd/ DVD/book: super classes of ITEM class and a library class.. In the library class i have 2 functions for cleaning up the sets.. Also, the CD, DVD, book destructors are not being called.. here is my potential leaks.. library.h #pragma once #include <ostream> #include <map> #include <set> #include <string> #include "Item.h" using namespace std; typedef set<Item*> ItemSet; typedef map<string,Item*> ItemMap; typedef map<string,ItemSet*> ItemSetMap; class Library { public: // general functions void addKeywordForItem(const Item* const item, const string& keyword); const ItemSet* itemsForKeyword(const string& keyword) const; void printItem(ostream& out, const Item* const item) const; // book-related functions const Item* addBook(const string& title, const string& author, int const nPages); const ItemSet* booksByAuthor(const string& author) const; const ItemSet* books() const; // music-related functions const Item* addMusicCD(const string& title, const string& band, const int nSongs); void addBandMember(const Item* const musicCD, const string& member); const ItemSet* musicByBand(const string& band) const; const ItemSet* musicByMusician(const string& musician) const; const ItemSet* musicCDs() const; // movie-related functions const Item* addMovieDVD(const string& title, const string& director, const int nScenes); void addCastMember(const Item* const movie, const string& member); const ItemSet* moviesByDirector(const string& director) const; const ItemSet* moviesByActor(const string& actor) const; const ItemSet* movies() const; ~Library(); void Purge(ItemSet &set); void Purge(ItemSetMap &map); }; here is some functions for adding info using new in library. Keep in mind i am cutting out alot of code to keep this post short. library.cpp #include "Library.h" #include "book.h" #include "cd.h" #include "dvd.h" #include <iostream> // general functions ItemSet allBooks; ItemSet allCDS; ItemSet allDVDs; ItemSetMap allBooksByAuthor; ItemSetMap allmoviesByDirector; ItemSetMap allmoviesByActor; ItemSetMap allMusicByBand; ItemSetMap allMusicByMusician; const ItemSet* Library::itemsForKeyword(const string& keyword) const { const StringSet* kw; ItemSet* obj = new ItemSet(); return obj; const Item* Library::addBook(const string& title, const string& author, const int nPages) { ItemSet* obj = new ItemSet(); Book* item = new Book(title,author,nPages); allBooks.insert(item); // add to set of all books obj->insert(item); return item; const Item* Library::addMusicCD(const string& title, const string& band, const int nSongs) { ItemSet* obj = new ItemSet(); CD* item = new CD(title,band,nSongs); return item; void Library::addBandMember(const Item* musicCD, const string& member) { ItemSet* obj = new ItemSet(); (((CD*) musicCD)->addBandMember(member)); obj->insert((CD*) musicCD); here is the library destructor..... Library::~Library() { Purge(allBooks); Purge(allCDS); Purge(allDVDs); Purge(allBooksByAuthor); Purge(allmoviesByDirector); Purge(allmoviesByActor); Purge(allMusicByBand); Purge(allMusicByMusician); } void Library::Purge(ItemSet &set) { for (ItemSet::iterator it = set.begin(); it != set.end(); ++it) delete *it; set.clear(); } void Library::Purge(ItemSetMap &map) { for (ItemSetMap::iterator it = map.begin(); it != map.end(); ++it) delete it->second; map.clear(); } so, basically item, cd, dvd class all have a set like this: typedef set<string> StringSet; class CD : public Item StringSet* music; and i am deleting it like: but those superclasses are not being called.. Item destructor is. CD::~CD() { delete music; } Do, i need a copy constructor? and how do i delete those objects i am creating in the library class? and how can i get the cd,dvd, destructor called? would the addbandmember function located in the library.cpp cause me to have a copy constructor? Any real help you can provide me to help me clean up this mess instead of telling me not to use pointers in my sets i would really appreciate. How can i delete the memory i am creating in those functions? I cannot delete them in the function!!

    Read the article

  • TypeError: Error #2007: Parameter child must be non-null.

    - by Bobby Francis Joseph
    I am running the following piece of code: package { import fl.controls.Button; import fl.controls.Label; import fl.controls.RadioButton; import fl.controls.RadioButtonGroup; import flash.display.Sprite; import flash.events.MouseEvent; import flash.text.TextFieldAutoSize; public class RadioButtonExample extends Sprite { private var j:uint; private var padding:uint = 10; private var currHeight:uint = 0; private var verticalSpacing:uint = 30; private var rbg:RadioButtonGroup; private var questionLabel:Label; private var answerLabel:Label; private var question:String = "What day is known internationally as Speak Like A Pirate Day?"; private var answers:Array = [ "August 12", "March 4", "September 19", "June 22" ]; public function RadioButtonExample() { setupQuiz(); } private function setupQuiz():void { setupQuestionLabel(); setupRadioButtons(); setupButton(); setupAnswerLabel(); } private function setupQuestionLabel():void { questionLabel = new Label(); questionLabel.text = question; questionLabel.autoSize = TextFieldAutoSize.LEFT; questionLabel.move(padding, padding + currHeight); currHeight += verticalSpacing; addChild(questionLabel); } private function setupAnswerLabel():void { answerLabel = new Label(); answerLabel.text = ""; answerLabel.autoSize = TextFieldAutoSize.LEFT; answerLabel.move(padding + 120, padding + currHeight); addChild(answerLabel); } private function setupRadioButtons():void { rbg = new RadioButtonGroup("question1"); createRadioButton(answers[0], rbg); createRadioButton(answers[1], rbg); createRadioButton(answers[2], rbg); createRadioButton(answers[3], rbg); } private function setupButton():void { var b:Button = new Button(); b.move(padding, padding + currHeight); b.label = "Check Answer"; b.addEventListener(MouseEvent.CLICK, checkAnswer); addChild(b); } private function createRadioButton(rbLabel:String, rbg:RadioButtonGroup):void { var rb:RadioButton = new RadioButton(); rb.group = rbg; rb.label = rbLabel; rb.move(padding, padding + currHeight); addChild(rb); currHeight += verticalSpacing; } private function checkAnswer(e:MouseEvent):void { if (rbg.selection == null) { return; } var resultStr:String = (rbg.selection.label == answers[2]) ? "Correct" : "Incorrect"; answerLabel.text = resultStr; } } } This is from Adobe Livedocs. http://www.adobe.com/livedocs/flash/9.0/ActionScriptLangRefV3/ I have added a Radiobutton to stage and then deleted it so that its there in the library. However I am getting the following error TypeError: Error #2007: Parameter child must be non-null. at flash.display::DisplayObjectContainer/addChildAt() at fl.controls::BaseButton/fl.controls:BaseButton::drawBackground() at fl.controls::LabelButton/fl.controls:LabelButton::draw() at fl.controls::Button/fl.controls:Button::draw() at fl.core::UIComponent/::callLaterDispatcher() Can anyone tell me what is going on and how to remove this error.

    Read the article

  • Is it good to subclass a class only to separate some functional parts?

    - by prostynick
    Suppose we have abstract class A (all examples in C#) public abstract class A { private Foo foo; public A() { } public void DoSomethingUsingFoo() { //stuff } public void DoSomethingElseUsingFoo() { //stuff } //a lot of other stuff... } But we are able to split it into two classes A and B: public abstract class A { public A() { } //a lot of stuff... } public abstract class B : A { private Foo foo; public B() : base() { } public void DoSomethingUsingFoo() { //stuff } public void DoSomethingElseUsingFoo() { //stuff } //nothing else or just some overrides of A stuff } That's good, but we are 99.99% sure, that no one will ever subclass A, because functionality in B is very important. Is it still good to have two separate classes only to split some code into two parts and to separate functional elements?

    Read the article

  • C# method generic params parameter bug?

    - by Mike M
    Hey, I appears to me as though there is a bug/inconsistency in the C# compiler. This works fine (first method gets called): public void SomeMethod(string message, object data); public void SomeMethod(string message, params object[] data); // .... SomeMethod("woohoo", item); Yet this causes "The call is ambiguous between the following methods" error: public void SomeMethod(string message, T data); public void SomeMethod(string message, params T[] data); // .... SomeMethod("woohoo", (T)item); I could just use the dump the first method entirely, but since this is a very performance sensitive library and the first method will be used about 75% of the time, I would rather not always wrap things in an array and instantiate an iterator to go over a foreach if there is only one item. Splitting into different named methods would be messy at best IMO. Thoughts?

    Read the article

  • C++ 'ClassName Not Declared' Error

    - by Arjun Nayini
    I have this cpp file. dsets.cpp: #ifndef DSETS_CPP #define DSET_CPP //Adds elements to the DisjointSet data structure. This function adds //x unconnected roots to the end of the array. void DisjointSets::addelements(int x){ } //Given an int this function finds the root associated with that node. int DisjointSets::find(int x){ return 0; } //This function reorders the uptree in order to represent the union of two //subtrees void DisjointSets::setunion(int x, int y){ } #endif and this header file dsets.h: #ifndef DSETS_H #define DSET_H #include <iostream> #include <vector> using namespace std; class DisjointSets { public: void addelements(int x); int find(int x); void setunion(int x, int y); private: vector<int> x; }; #include "dsets.cpp" #endif And I keep getting an error that is saying that "DisjointSets has no been declared" ~ ~

    Read the article

  • How to invoke a delegate with a null parameter?

    - by Rodney Burton
    I get a null exception if I try to pass a null parameter to a delegate during an invoke. Here's what the code looks like: public void RequestPhoto() { WCF.Service.BeginGetUserPhoto(Contact.UserID, new AsyncCallback(RequestPhotoCB), null); } public void RequestPhotoCB(IAsyncResult result) { var photo = WCF.Service.EndGetUserPhoto(result); UpdatePhoto(photo); } public delegate void UpdatePhotoDelegate(Binary photo); public void UpdatePhoto(Binary photo) { if (InvokeRequired) { var d = new UpdatePhotoDelegate(UpdatePhoto); Invoke(d, new object[] { photo }); } else { var ms = new MemoryStream(photo.ToArray()); var bmp = new Bitmap(ms); pbPhoto.BackgroundImage = bmp; } } The problem is with the line: Invoke(d, new object[] { photo }); If the variable "photo" is null. What is the correct way to pass a null parameter during an invoke? Thanks!

    Read the article

  • Class inheriting from several Interfaces having same method signature

    - by Manish
    Say, I have three interfaces: public interface I1 { void XYZ(); } public interface I2 { void XYZ(); } public interface I3 { void XYZ(); } A class inheriting from these three interfaces: class ABC: I1,I2, I3 { // method definitions } Questions: If I implement like this: class ABC: I1,I2, I3 { public void XYZ() { MessageBox.Show("WOW"); } } It compiles well and runs well too! Does it mean this single method implementation is sufficient for inheriting all the three Interfaces? How can I implement the method of all the three interfaces and CALL THEM? I know it can done using explicit implementation but I'm not able to call them. :(

    Read the article

  • Android app hanging, sometimes until Force Close / Wait dialog appears

    - by fredley
    I'm making an app that records uncompressed (wav format) audio. I'm using this class to actually record the audio. Currently, my application records fine (I can play the file), however when I click the button to stop the recording, the app hangs for 10 seconds or so, with no log output or any signs of life. Finally it comes round, dumps a load of errors into the log, updates the UI etc. I'm using AsyncTasks to try and avoid this kind of thing but it's not working. Here's my code: //Called on clicks of the record button. rar is the instance of RehearsalAudioRecorder private OnClickListener RecordListener = new OnClickListener(){ @Override public void onClick(View v) { Log.d("Record","Click"); if (recording){ new stopRecordingTask().execute(rar,null,null); startStop.setText("Record"); statusBar.setText("Recording Finished, ready to Encode"); }else{ recording = true; new startRecordingTask().execute(rar,null,null); startStop.setText("Stop"); statusBar.setText("Recording Started"); } } }; private class startRecordingTask extends AsyncTask<RehearsalAudioRecorder,Void,Void>{ @Override protected Void doInBackground(RehearsalAudioRecorder... rs) { RehearsalAudioRecorder r = rs[0]; r.setOutputFile("/sdcard/rarOut.wav"); r.prepare(); r.start(); return null; } } private class stopRecordingTask extends AsyncTask<RehearsalAudioRecorder,Void,Void>{ @Override protected Void doInBackground(RehearsalAudioRecorder... rs) { RehearsalAudioRecorder r = rs[0]; r.stop(); r.reset(); return null; } } In Logcat, I always get output like this, which has me stumped. I have no idea what's causing it (I'm logging the RehearsalAudioRecorder class, and it's being started/stopped correctly by the button clicks. This output occurs after the log output for the button click and correct stop() method call) 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: STOPPED 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: ERROR 12-19 11:59:11.172: ERROR/AudioRecord-JNI(22662): Unable to retrieve AudioRecord object, can't record 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): Error occured in updateListener, recording is aborted 12-19 11:59:11.172: ERROR/uk.ac.cam.tfmw2.steg.RehearsalAudioRecorder(22662): stop() called on illegal state: ERROR ... 10 or more times I've been fiddling with this all day and I'm not getting anywhere, any input would be greatly appreciated. Update I've replace the AsyncTasks with Threads, still doesn't work, the app completely hangs when I click record, despite the fact the Log indicates there's nothing going on in the main thread. Still completely stumped.

    Read the article

  • How do I define a template class and divide it into multiple files?

    - by hkBattousai
    I have written a simple template class for test purpose. It compiles without any errors, but when I try to use it in main(), it give some linker errors. main.cpp #include <iostream> #include "MyNumber.h" int wmain(int argc, wchar_t * argv[]) { MyNumber<float> num; num.SetValue(3.14); std::cout << "My number is " << num.GetValue() << "." << std::endl; system("pause"); return 0; } MyNumber.h #pragma once template <class T> class MyNumber { public: MyNumber(); ~MyNumber(); void SetValue(T val); T GetValue(); private: T m_Number; }; MyNumber.cpp #include "MyNumber.h" template <class T> MyNumber<T>::MyNumber() { m_Number = static_cast<T>(0); } template <class T> MyNumber<T>::~MyNumber() { } template <class T> void MyNumber<T>::SetValue(T val) { m_Number = val; } template <class T> T MyNumber<T>::GetValue() { return m_Number; } When I build this code, I get the following linker errors: Error 7 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\X64\Debug\Console Demo.exe 1 error LNK1120: 4 unresolved externals Error 3 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: __cdecl MyNumber::~MyNumber(void)" (??1?$MyNumber@M@@QEAA@XZ) referenced in function wmain Error 6 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: __cdecl MyNumber::MyNumber(void)" (??0?$MyNumber@M@@QEAA@XZ) referenced in function wmain Error 4 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: float __cdecl MyNumber::GetValue(void)" (?GetValue@?$MyNumber@M@@QEAAMXZ) referenced in function wmain Error 5 Console Demo C:\Development\IDE\Visual Studio 2010\SAVE\Grand Solution\Console Demo\main.obj error LNK2019: unresolved external symbol "public: void __cdecl MyNumber::SetValue(float)" (?SetValue@?$MyNumber@M@@QEAAXM@Z) referenced in function wmain But, if I leave main() empty, I don't get any linker errors. What is wrong with my template class? What am I doing wrong?

    Read the article

  • C++0x rvalue references - lvalues-rvalue binding

    - by Doug
    This is a follow-on question to http://stackoverflow.com/questions/2748866/c0x-rvalue-references-and-temporaries In the previous question, I asked how this code should work: void f(const std::string &); //less efficient void f(std::string &&); //more efficient void g(const char * arg) { f(arg); } It seems that the move overload should probably be called because of the implicit temporary, and this happens in GCC but not MSVC (or the EDG front-end used in MSVC's Intellisense). What about this code? void f(std::string &&); //NB: No const string & overload supplied void g1(const char * arg) { f(arg); } void g2(const std::string & arg) { f(arg); } It seems that, based on the answers to my previous question that function g1 is legal (and is accepted by GCC 4.3-4.5, but not by MSVC). However, GCC and MSVC both reject g2 because of clause 13.3.3.1.4/3, which prohibits lvalues from binding to rvalue ref arguments. I understand the rationale behind this - it is explained in N2831 "Fixing a safety problem with rvalue references". I also think that GCC is probably implementing this clause as intended by the authors of that paper, because the original patch to GCC was written by one of the authors (Doug Gregor). However, I don't this is quite intuitive. To me, (a) a const string & is conceptually closer to a string && than a const char *, and (b) the compiler could create a temporary string in g2, as if it were written like this: void g2(const std::string & arg) { f(std::string(arg)); } Indeed, sometimes the copy constructor is considered to be an implicit conversion operator. Syntactically, this is suggested by the form of a copy constructor, and the standard even mentions this specifically in clause 13.3.3.1.2/4, where the copy constructor for derived-base conversions is given a higher conversion rank than other implicit conversions: A conversion of an expression of class type to the same class type is given Exact Match rank, and a conversion of an expression of class type to a base class of that type is given Conversion rank, in spite of the fact that a copy/move constructor (i.e., a user-defined conversion function) is called for those cases. (I assume this is used when passing a derived class to a function like void h(Base), which takes a base class by value.) Motivation My motivation for asking this is something like the question asked in http://stackoverflow.com/questions/2696156/how-to-reduce-redundant-code-when-adding-new-c0x-rvalue-reference-operator-over ("How to reduce redundant code when adding new c++0x rvalue reference operator overloads"). If you have a function that accepts a number of potentially-moveable arguments, and would move them if it can (e.g. a factory function/constructor: Object create_object(string, vector<string>, string) or the like), and want to move or copy each argument as appropriate, you quickly start writing a lot of code. If the argument types are movable, then one could just write one version that accepts the arguments by value, as above. But if the arguments are (legacy) non-movable-but-swappable classes a la C++03, and you can't change them, then writing rvalue reference overloads is more efficient. So if lvalues did bind to rvalues via an implicit copy, then you could write just one overload like create_object(legacy_string &&, legacy_vector<legacy_string> &&, legacy_string &&) and it would more or less work like providing all the combinations of rvalue/lvalue reference overloads - actual arguments that were lvalues would get copied and then bound to the arguments, actual arguments that were rvalues would get directly bound. Questions My questions are then: Is this a valid interpretation of the standard? It seems that it's not the conventional or intended one, at any rate. Does it make intuitive sense? Is there a problem with this idea that I"m not seeing? It seems like you could get copies being quietly created when that's not exactly expected, but that's the status quo in places in C++03 anyway. Also, it would make some overloads viable when they're currently not, but I don't see it being a problem in practice. Is this a significant enough improvement that it would be worth making e.g. an experimental patch for GCC?

    Read the article

  • c# multi inheritance

    - by user326839
    So ive got a base class which requires a Socket: class Sock { public Socket s; public Sock(Socket s) { this.s = s; } public virtual void Process(byte[] data) { } ... } then ive got another class. if a new socket gets accepted a new instance of this class will be created: class Game : Sock { public Random Random = new Random(); public Timerr Timers; public Test Test; public Game(Socket s) : base(s) { } public static void ReceiveNewSocket(object s) { Game Client = new Game((Socket)s); Client.Start(); } public override void Process(byte[] buf) { Timers = new Timerr(s); Test = new Test(s); Test.T(); } } in the Sock class ive got a virtual function that gets overwritten by the Game class.(Process function) in this function im calling a function from the Test Class(Test+ Timerr Class: class Test : Game { public Test(Socket s) : base(s) { } public void T() { Console.WriteLine(Random.Next(0, 10)); Timers.Start(); } } class Timerr : Game { public Timerr(Socket s) : base(s) { } public void Start() { Console.WriteLine("test"); } } ) So in the Process function im calling a function in Test. And in this function(T) i need to call a function from the Timerr Class.But the problem is its always NULL , although the constructor is called in Process. And e.g. the Random Class can be called, i guess its because its defined with the constructor.: public Random Random = new Random(); and thats why the other classes(without a constructor): public Timerr Timers; public Test Test; are always null in the inherited class Test.But its essentiel that i call other Methods of other classes in this function.How could i solve that?

    Read the article

  • Implementation/interface inheritance design question.

    - by Neil G
    I would like to get the stackoverflow community's opinion on the following three design patterns. The first is implementation inheritance; the second is interface inheritance; the third is a middle ground. My specific question is: Which is best? implementation inheritance: class Base { X x() const = 0; void UpdateX(A a) { y_ = g(a); } Y y_; } class Derived: Base { X x() const { return f(y_); } } interface inheritance: class Base { X x() const = 0; void UpdateX(A a) = 0; } class Derived: Base { X x() const { return x_; } void UpdateX(A a) { x_ = f(g(a)); } X x_; } middle ground: class Base { X x() const { return x_; } void UpdateX(A a) = 0; X x_; } class Derived: Base { void UpdateX(A a) { x_ = f(g(a)); } } I know that many people prefer interface inheritance to implementation inheritance. However, the advantage of the latter is that with a pointer to Base, x() can be inlined and the address of x_ can be statically calculated.

    Read the article

  • Assemblies mysteriously loaded into new AppDomains

    - by Eric
    I'm testing some code that does work whenever assemblies are loaded into an appdomain. For unit testing (in VS2k8's built-in test host) I spin up a new, uniquely-named appdomain prior to each test with the idea that it should be "clean": [TestInitialize()] public void CalledBeforeEachTestMethod() { AppDomainSetup appSetup = new AppDomainSetup(); appSetup.ApplicationBase = @"G:\<ProjectDir>\bin\Debug"; Evidence baseEvidence = AppDomain.CurrentDomain.Evidence; Evidence evidence = new Evidence( baseEvidence ); _testAppDomain = AppDomain.CreateDomain( "myAppDomain" + _appDomainCounter++, evidence, appSetup ); } [TestMethod] public void MissingFactoryCausesAppDomainUnload() { SupportingClass supportClassObj = (SupportingClass)_testAppDomain.CreateInstanceAndUnwrap( GetType().Assembly.GetName().Name, typeof( SupportingClass ).FullName ); try { supportClassObj.LoadMissingRegistrationAssembly(); Assert.Fail( "Should have nuked the app domain" ); } catch( AppDomainUnloadedException ) { } } [TestMethod] public void InvalidFactoryMethodCausesAppDomainUnload() { SupportingClass supportClassObj = (SupportingClass)_testAppDomain.CreateInstanceAndUnwrap( GetType().Assembly.GetName().Name, typeof( SupportingClass ).FullName ); try { supportClassObj.LoadInvalidFactoriesAssembly(); Assert.Fail( "Should have nuked the app domain" ); } catch( AppDomainUnloadedException ) { } } public class SupportingClass : MarshalByRefObject { public void LoadMissingRegistrationAssembly() { MissingRegistration.Main(); } public void LoadInvalidFactoriesAssembly() { InvalidFactories.Main(); } } If every test is run individually I find that it works correctly; the appdomain is created and has only the few intended assemblies loaded. However, if multiple tests are run in succession then each _testAppDomain already has assemblies loaded from all previous tests. Oddly enough, the two tests get appdomains with different names. The test assemblies that define MissingRegistration and InvalidFactories (two different assemblies) are never loaded into the unit test's default appdomain. Can anyone explain this behavior?

    Read the article

  • Save HashMap data into SQLite

    - by Matthew
    I'm Trying to save data from Json into SQLite. For now I keep the data from Json into HashMap. I already search it, and there's said use the ContentValues. But I still don't get it how to use it. I try looking at this question save data to SQLite from json object using Hashmap in Android, but it doesn't help a lot. Is there any option that I can use to save the data from HashMap into SQLite? Here's My code. MainHellobali.java // Hashmap for ListView ArrayList<HashMap<String, String>> all_itemList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main_helloballi); all_itemList = new ArrayList<HashMap<String, String>>(); // Calling async task to get json new getAllItem().execute(); } private class getAllItem extends AsyncTask<Void, Void, Void> { @Override protected Void doInBackground(Void... arg0) { // Creating service handler class instance ServiceHandler sh = new ServiceHandler(); // Making a request to url and getting response String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET); Log.d("Response: ", "> " + jsonStr); if (jsonStr != null) { try { all_item = new JSONArray(jsonStr); // looping through All Contacts for (int i = 0; i < all_item.length(); i++) { JSONObject c = all_item.getJSONObject(i); String item_id = c.getString(TAG_ITEM_ID); String category_name = c.getString(TAG_CATEGORY_NAME); String item_name = c.getString(TAG_ITEM_NAME); // tmp hashmap for single contact HashMap<String, String> allItem = new HashMap<String, String>(); // adding each child node to HashMap key => value allItem.put(TAG_ITEM_ID, item_id); allItem.put(TAG_CATEGORY_NAME, category_name); allItem.put(TAG_ITEM_NAME, item_name); // adding contact to contact list all_itemList.add(allItem); } } catch (JSONException e) { e.printStackTrace(); } } else { Log.e("ServiceHandler", "Couldn't get any data from the url"); } return null; } } I have DatabasehHandler.java and AllItem.java too. I can put it in here if its necessary. Thanks before ** Add Edited Code ** // looping through All Contacts for (int i = 0; i < all_item.length(); i++) { JSONObject c = all_item.getJSONObject(i); String item_id = c.getString(TAG_ITEM_ID); String category_name = c.getString(TAG_CATEGORY_NAME); String item_name = c.getString(TAG_ITEM_NAME); DatabaseHandler databaseHandler = new DatabaseHandler(this); //error here "The Constructor DatabaseHandler(MainHellobali.getAllItem) is undefined }

    Read the article

  • how do call a polymorphic function from an agnostic function?

    - by sds
    I have a method foo void foo (String x) { ... } void foo (Integer x) { ... } and I want to call it from a method which does not care about the argument: void bar (Iterable i) { ... for (Object x : i) foo(x); // this is the only time i is used ... } the code above complains that that foo(Object) is not defined and when I add void foo (Object x) { throw new Exception; } then bar(Iterable<String>) calls that instead of foo(String) and throws the exception. How do I avoid having two textually identical definitions of bar(Iterable<String>) and bar(Iterable<Integer>)? I thought I would be able to get away with something like <T> void bar (Iterable<T> i) { ... for (T x : i) foo(x); // this is the only time i is used ... } but then I get cannot find foo(T) error.

    Read the article

  • Should methods that are required to be executed in a specific order be private?

    - by TooFat
    I have a Class that retrieves some data and images does some stuff to them and them uploads them to a third party app using web services. The object needs to perform some specific steps in order. My question is should I be explicitly exposing each method publicly like so. myObject obj = new myObject(); obj.RetrieveImages(); obj.RetrieveAssociatedData(); obj.LogIntoThirdPartyWebService(); obj.UploadStuffToWebService(); or should all of these methods be private and encapsulated in a single public method like so. public class myObject() { private void RetrieveImages(){}; private void RetrieveAssociatedData(){}; private void LogIntoThirdPartyWebService(){}; private void UploadStuffToWebService(){}; public void DoStuff() { this.RetrieveImages(); this.RetrieveAssociatedData(); this.LogIntoThirdPartyWebService(); this.UploadStuffToWebService(); } } which is called like so. myObject obj = new myObject(); obj.DoStuff();

    Read the article

  • Declaration, allocation and assignment of an array of pointers to function pointers

    - by manneorama
    Hello Stack Overflow! This is my first post, so please be gentle. I've been playing around with C from time to time in the past. Now I've gotten to the point where I've started a real project (a 2D graphics engine using SDL, but that's irrelevant for the question), to be able to say that I have some real C experience. Yesterday, while working on the event system, I ran into a problem which I couldn't solve. There's this typedef, //the void parameter is really an SDL_Event*. //but that is irrelevant for this question. typedef void (*event_callback)(void); which specifies the signature of a function to be called on engine events. I want to be able to support multiple event_callbacks, so an array of these callbacks would be an idea, but do not want to limit the amount of callbacks, so I need some sort of dynamic allocation. This is where the problem arose. My first attempt went like this: //initial size of callback vector static const int initial_vecsize = 32; //our event callback vector static event_callback* vec = 0; //size static unsigned int vecsize = 0; void register_event_callback(event_callback func) { if (!vec) __engine_allocate_vec(vec); vec[vecsize++] = func; //error here! } static void __engine_allocate_vec(engine_callback* vec) { vec = (engine_callback*) malloc(sizeof(engine_callback*) * initial_vecsize); } First of all, I have omitted some error checking as well as the code that reallocates the callback vector when the number of callbacks exceed the vector size. However, when I run this code, the program crashes as described in the code. I'm guessing segmentation fault but I can't be sure since no output is given. I'm also guessing that the error comes from a somewhat flawed understanding on how to declare and allocate an array of pointers to function pointers. Please Stack Overflow, guide me.

    Read the article

  • How can I ignore an http request without clearing the browser?

    - by Timid Developer
    To prevent duplicate requests (i.e. pressing F5 right after clicking a command button), I've setup my page base class to ignore the request if it's detected as a duplicate. When I say 'ignore' I mean Response.End() Now I thought I've seen this work before, where there's an issue, I just Response.End() and the users page just does nothing. I don't know the exact circumstance in which this worked, but I'm unable to repeat it now. Now when I call Response.End(), I just get an empty browser. More specifically, I get this html. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=utf-8"></HEAD> <BODY></BODY></HTML> I setup the following test app to confirm the problem is not elsewhere in my app. Here it is: Add the following to an aspx form <asp:Label ID="lbl" Text="0" runat="server" /><br /> <asp:Button ID="btnAdd1" Text="Add 1" runat="server" /><br /> <asp:Button ID="btnAdd2" Text="Add 2" runat="server" /><br /> <asp:Button ID="btnAdd3" Text="Add 3" runat="server" /><br /> And here's the code behind file using System; namespace TestDupRequestCancellation { public partial class _Default : System.Web.UI.Page { protected void Page_Init(object sender, EventArgs e) { btnAdd1.Click += btnAdd1_Click; btnAdd2.Click += btnAdd2_Click; btnAdd3.Click += btnAdd3_Click; } protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) CurrentValue = 0; else if (Int32.Parse(lbl.Text) != CurrentValue) Response.End(); } protected void Page_PreRender(object sender, EventArgs e) { lbl.Text = CurrentValue.ToString(); } protected int CurrentValue { get { return Int32.Parse(Session["CurrentValue"].ToString()); } set { Session["CurrentValue"] = value.ToString(); } } void btnAdd3_Click(object sender, EventArgs e) { CurrentValue += 3; } void btnAdd2_Click(object sender, EventArgs e) { CurrentValue += 2; } void btnAdd1_Click(object sender, EventArgs e) { CurrentValue += 1; } } } When you load the page, clicking any button does what is expected, but if you press F5 at any time after pressing one of the buttons, it will detect it as a duplicate request and call Response.End() which promptly ends the task. Which leaves the user with an empty browser. Is there anyway to leave the user with the page as it was, so they can just click a button? Also; please note that this code is the simplest code I could come up with to demonstrate my problem. It's not meant to demonstrate how to check for dup requests.

    Read the article

  • Loading Views dynamically

    - by Dann
    Case 1: I have created View-based sample application and tried execute below code. When I press on "Job List" button it should load another view having "Back Btn" on it. In test function, if I use [self.navigationController pushViewController:jbc animated:YES]; nothing gets loaded, but if I use [self presentModalViewController:jbc animated:YES]; it loads another view haveing "Back Btn" on it. Case 2: I did create another Navigation Based Applicaton and used [self.navigationController pushViewController:jbc animated:YES]; it worked as I wanted. Can someone please explain why it was not working in Case 1. Does it has something to do with type of project that is selected? @interface MWViewController : UIViewController { } -(void) test; @end @interface JobViewCtrl : UIViewController { } @end @implementation MWViewController (void)viewDidLoad { UIButton* btn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; btn.frame = CGRectMake(80, 170, 150, 35); [btn setTitle:@"Job List!" forState:UIControlStateNormal]; [btn addTarget:self action:@selector(test) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:btn]; [super viewDidLoad]; } -(void) test { JobViewCtrl* jbc = [[JobViewCtrl alloc] init]; [self.navigationController pushViewController:jbc animated:YES]; //[self presentModalViewController:jbc animated:YES]; [jbc release]; } (void)dealloc { [super dealloc]; } @end @implementation JobViewCtrl -(void) loadView { self.view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]]; self.view.backgroundColor = [UIColor grayColor]; UIButton* btn = [UIButton buttonWithType:UIButtonTypeRoundedRect]; btn.frame = CGRectMake(80, 170, 150, 35); [btn setTitle:@"Back Btn!" forState:UIControlStateNormal]; [self.view addSubview:btn]; } @end

    Read the article

  • Is this a valid pattern for raising events in C#?

    - by Will Vousden
    Update: For the benefit of anyone reading this, since .NET 4, the lock is unnecessary due to changes in synchronization of auto-generated events, so I just use this now: public static void Raise<T>(this EventHandler<T> handler, object sender, T e) where T : EventArgs { if (handler != null) { handlerCopy(sender, e); } } And to raise it: SomeEvent.Raise(this, new FooEventArgs()); Having been reading one of Jon Skeet's articles on multithreading, I've tried to encapsulate the approach he advocates to raising an event in an extension method like so (with a similar generic version): public static void Raise(this EventHandler handler, object @lock, object sender, EventArgs e) { EventHandler handlerCopy; lock (@lock) { handlerCopy = handler; } if (handlerCopy != null) { handlerCopy(sender, e); } } This can then be called like so: protected virtual void OnSomeEvent(EventArgs e) { this.someEvent.Raise(this.eventLock, this, e); } Are there any problems with doing this? Also, I'm a little confused about the necessity of the lock in the first place. As I understand it, the delegate is copied in the example in the article to avoid the possibility of it changing (and becoming null) between the null check and the delegate call. However, I was under the impression that access/assignment of this kind is atomic, so why is the lock necessary? Update: With regards to Mark Simpson's comment below, I threw together a test: static class Program { private static Action foo; private static Action bar; private static Action test; static void Main(string[] args) { foo = () => Console.WriteLine("Foo"); bar = () => Console.WriteLine("Bar"); test += foo; test += bar; test.Test(); Console.ReadKey(true); } public static void Test(this Action action) { action(); test -= foo; Console.WriteLine(); action(); } } This outputs: Foo Bar Foo Bar This illustrates that the delegate parameter to the method (action) does not mirror the argument that was passed into it (test), which is kind of expected, I guess. My question is will this affect the validity of the lock in the context of my Raise extension method? Update: Here is the code I'm now using. It's not quite as elegant as I'd have liked, but it seems to work: public static void Raise<T>(this object sender, ref EventHandler<T> handler, object eventLock, T e) where T : EventArgs { EventHandler<T> copy; lock (eventLock) { copy = handler; } if (copy != null) { copy(sender, e); } }

    Read the article

  • Replicating Java's DecimalFormat in C#

    - by Frank Krueger
    I am trying to replicate a subset of Java's DecimalFormat class. Below is what I've come up with. Does this look right to everyone? public class DecimalFormat : NumberFormat { int _maximumFractionDigits; int _minimumFractionDigits; string _format; void RebuildFormat () { _format = "{0:0."; _format += new string ('0', _minimumFractionDigits); if (_maximumFractionDigits > _minimumFractionDigits) { _format += new string ('#', _maximumFractionDigits - _minimumFractionDigits); } _format += "}"; } public override string format (object value) { return string.Format (_format, value); } public override void setMaximumFractionDigits (int n) { _maximumFractionDigits = n; RebuildFormat (); } public override void setMinimumFractionDigits (int n) { _minimumFractionDigits = n; RebuildFormat (); } public override void setGroupingUsed (bool g) { } public static NumberFormat getInstance () { return new DecimalFormat (); } }

    Read the article

< Previous Page | 97 98 99 100 101 102 103 104 105 106 107 108  | Next Page >