Search Results

Search found 47200 results on 1888 pages for 'null object pattern'.

Page 108/1888 | < Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >

  • BitmapFactory.decodeResource returns null value

    - by krasnoff
    I am tring to load bitmaps from an internal resource in a View object (the source itself is in "drawable" files). the code is: import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.util.AttributeSet; import android.view.View; public class BannerView extends View { private Bitmap m_Banner = null; public BannerView(Context context, AttributeSet attributeSet) { super(context, attributeSet); m_Banner = BitmapFactory.decodeResource(getResources(), R.drawable.banner); } } Why m_Banner value is null? thank you in advance Kobi

    Read the article

  • getResourceAsStream() is always returning null

    - by Andreas Grech
    I have the following structure in a Java Web Application: TheProject -- [Web Pages] -- -- [WEB-INF] -- -- -- abc.txt -- -- index.jsp -- [Source Packages] -- -- [wservices] -- -- -- WS.java In WS.java, I am using the following code in a Web Method: InputStream fstream = this.getClass().getResourceAsStream("abc.txt"); But it is always returning a null. I need to read from that file, and I read that if you put the files in WEB-INF, you can access them with getResourceAsStream, yet the method is always returning a null. Any ideas of what I may be doing wrong? Btw, the strange thing is that this was working, but after I performed a Clean and Build on the Project, it suddenly stopped working :/

    Read the article

  • Oracle: Finding Columns with only null values

    - by Jorge Valois
    I have a table with a lot of columns and a type column. Some columns seem to be always empty for a specific type. I want to create a view for each type and only show the relevant columns for each type. Working under the assumption that if a column has ONLY null values for a specific type, then that columns should not be part of the view, how can you find that out with queries? Is there a SELECT [columnName] FROM [table] WHERE [columnValues] ARE ALL [null] I know I COMPLETELY made it all up above... I'm just trying to get the idea across. Thanks in advance!

    Read the article

  • .save puts NULL in user_id field in Ruby on Rails

    - by mathee
    Here's the model file: class ProfileTag < ActiveRecord::Base def self.create_or_update(options = {}) id = options.delete(:id) record = find_by_id(id) || new record.id = id record.attributes = options puts "record.profile_id is" puts record.profile_id record.save! record end end This gives me the correct print out in my log. But it also says that there's a call to UPDATE that sets profile_id to NULL. I'm not sure I understand why the INSERT puts the value into profile_id properly, but then it sets it to NULL on an UPDATE. If you need more specifics, please let me know. I'm thinking that the save functionality does many things other than INSERTs into the database, but I don't know what I need to specify so that it will properly set profile_id.

    Read the article

  • Checking sqlite datetime NULL with RoR

    - by Paul N
    RoR/SQL newbie here. My datetime column 'deleted_at' are all uninitialized. Running this query returns an error: SELECT * FROM variants v ON v.id = ovv0.variant_id INNER JOIN option_values_variants ovv1 ON v.id = ovv1.variant_id INNER JOIN option_values_variants ovv2 ON v.id = ovv2.variant_id INNER JOIN option_values_variants ovv3 ON v.id = ovv3.variant_id INNER JOIN option_values_variants ovv4 ON v.id = ovv4.variant_id WHERE v.deleted_at = NULL AND v.product_id = 1060500595 However, if I set my datetime values to 0, and set my query to v.deleted_at = 0, the correct variant is returned to me. How do I check for uninitialized/NULL datetimes?

    Read the article

  • Which is the better way to simulate optional parameters in Java?

    - by froadie
    I have a Java method that takes 3 parameters, and I'd like it to also have a 4th "optional" parameter. I know that Java doesn't support optional parameters directly, so I coded in a 4th parameter and when I don't want to pass it I pass null. (And then the method checks for null before using it.) I know this is kind of clunky... but the other way is to overload the method which will result in quite a bit of duplication. Which is the better way to implement optional method parameters in Java: using a nullable parameter, or overloading? And why?

    Read the article

  • PHP radio button check if null

    - by Dallox
    So in class we get this school task where we need to check if one of the fields in unfilled and display an error. No we did this but for some strange reason it doesnt display a error when a radio button is unchecked. (textfield null check works fine) I've tried with a friend many possabilities but they all doesnt seem to work. We have been stuck at this task for 2 hours. Now we have tried making seperate if's but that doesnt seem to work too. These are the important parts: <p> <input type="hidden" name="taal" value="false"> Choose a language <input type="radio" name="taal" value="N"> Dutch <input type="radio" name="taal" value="E"> English <input type="radio" name="taal" value="S"> Spanish if (@$_POST['taal'] == null){ echo "No Language gotten"; return; }

    Read the article

  • returning null or throwing an exception?

    - by MoKi
    I have the following types: typedef QPair < QTime , QTime > CalculatedTimeSlotRange; typedef QList < CalculatedTimeSlotRange > CalculatedTimeSlotRangeList; typedef QHash < quint8 , CalculatedTimeSlotRangeList > TimeSlotsTable; I have a function like the following: const CalculatedTimeSlotRangeList* TimeSlots::getCalculatedTimeSlotRangeList(const quint8 id) const { QHashIterator<quint8,CalculatedTimeSlotRangeList> it(mTimeSlotsTable); while (it.hasNext()) { it.next(); if(it.key() == id) { return &it.value(); } } return NULL; } as you can see my function returns a null if it fails to find a key that matches id. Is this correct? or should I just throw an exception if the key does not exist? how should i throw an exception for this situation?

    Read the article

  • Drupal - db_fetch_array returns NULL for every row

    - by darudude
    I'm using Drupal's db_fetch_array to fetch rows from my db_query. However, every row returned is equal to NULL. Typing the query into PHP myadmin works, so I have no idea whats going on. db_num_rows returns the number of rows as well. Here is the code: if(count($rebuild_ids)) { $ids=implode(",",$rebuild_ids); $type_stmt = "SELECT * from {" . ItemType::$type_table_name . "} where id IN ($ids)"; $new_items=db_query($type_stmt); if(!$new_items || db_num_rows($new_items) == 0) { return; } while($row = db_fetch_array($new_items)); { if ($row!=NULL) { echo "I work!" $game_items[] = $row['id']; ItemInstance::$nid_to_item_type_code[$row['nid']] = $row['id']; } } } However, it never gets into the third if statement (i.e. never echos "I work!") Any ideas?

    Read the article

  • Acceptable name for extension method that accept null

    - by GaryX
    Hi, I really don't like to call String.IsNullOrEmpty(str). That makes me need to think "String" class first, then call it on the object "str". I like to call str.IsNullOrEmpty(), which doesn't need me to think "String" class. The problem is that extension method accept null instance to call on, which is not the usual case when you call a normal method. My question what do you think will be a convetion name for extension methods that accept null? For string, that is easy, "IsNullOrEmpty()" (anything that contains "IsNull") sounds good for me. For others, like GetDisplayName(), do we name it as "NullOrGetDisplayName" ?

    Read the article

  • Using "as" and expecting a null return

    - by DrLazer
    For example. Lets say we have a stackpanel on a form. Its full of both Grids and Labels. I want to loop through all the Grids and do some operation on them but leave the Lables intact. At the moment I am doing it this way. foreach(UIElement element in m_stacker.Children) { Grid block = element as Grid; if(block != null) { //apply changes here } } So i'm using the fact that "as" returns null if it cannot cast into the required type. Is this an ok thing to do or is there a better solution to this problem?

    Read the article

  • null pointer exception in textview of setcontent

    - by kitokid
    I am getting the java.lang.NullPointerException on createTabContent for the following code. There are two tabspecs. When I called and set the tab , changed the tabs for the first time it is ok. But when i called again while I am on the second tab, its hit the null pointer exception for line : NoStudentText.setVisibility(View.VISIBLE); I will show No Student Text if there is no data for the student list. It shows the text for the first time call. But If I do second time call to that tab, got the error. tspecStudent.setContent(new TabContentFactory() { public View createTabContent(String arg0) { if(listStudent != null && listStudent .size() > 0) { //show the student list } else { TextView noStudentText = (TextView)findViewById(R.id.NoStudentText); noStudentText.setVisibility(View.VISIBLE); return noStudentText; } } });

    Read the article

  • singleton pattern in java- lazy Intialization

    - by flash
    public static MySingleton getInstance() { if (_instance==null) { synchronized (MySingleton.class) { _instance = new MySingleton(); } } return _instance; } 1.is there a flaw with the above implementation of the getInstance method? 2.What is the difference between the two implementations.? public static synchronized MySingleton getInstance() { if (_instance==null) { _instance = new MySingleton(); } return _instance; } I have seen a lot of answers on the singleton pattern in stackoverflow but the question I have posted is to know mainly difference of 'synchronize' at method and block level in this particular case.

    Read the article

  • Why is this C++ code working ?

    - by gregseth
    Why doesn't the program segfault on the p->info() call? struct A { int info() { retrun (this) ? 1 : -1; } }; int main() { A* p = NULL; if (p->info() == 1) { cout << "I'm alive!" << endl; } else { cout << "I'm NULL..." << endl; } return 0; }

    Read the article

  • display data from tables that contain a null value

    - by user2631662
    I need the code below to say - if myReader reads a null entry a new method is called. At the moment it will not display data from tables that contain a null value conDataBase.Open(); myReader = cmdDataBase.ExecuteReader(); while (myReader.Read()) { if (myReader["Code_CodeID"] != DBNull.Value) { string sFirst = myReader["First"].ToString(); string sLast = myReader["Last"].ToString(); string sAdd1 = myReader["Address1"].ToString(); string sCode = myReader["Code"].ToString(); txtFirst.Text = sFirst; txtSecond.Text = sLast; txtadd1.Text = sAdd1; txtDeviceIMEI.Text = sCode; } } } else { //go to a new method } }

    Read the article

  • String[] initialized by null???

    - by Esmond
    Hi i encountered this problem whereby when i initialized my String[], there seems to be a null in the String[] before i do anything. How do i initialized the String[] to be completely empty,i.e. without the null at the start? The output for the following code is: nullABC nullABC nullABC nullABC nullABC public static void main(String[] args){ String[] inputArr = new String[5]; for (int i = 0; i< inputArr.length; i++){ inputArr[i] += "ABC"; } for (int i = 0; i< inputArr.length; i++){ System.out.println(inputArr[i]); } } }

    Read the article

  • Is there a factory pattern to prevent multiple instances for same object (instance that is Equal) good design?

    - by dsollen
    I have a number of objects storing state. There are essentially two types of fields. The ones that uniquely define what the object is (what node, what edge etc), and the others that store state describing how these things are connected (this node is connected to these edges, this edge is part of these paths) etc. My model is updating the state variables using package methods, so all these objects act as immutable to anyone not in Model scope. All Objects extend one base type. I've toyed with the idea of a Factory approach which accepts a Builder object and constructs the applicable object. However, if an instance of the object already exists (ie would return true if I created the object defined by the builder and passed it to the equal method for the existing instance) the factory returns the current object instead of creating a new instance. Because the Equal method would only compare what uniquely defines the type of object (this is node A to node B) but won't check the dynamic state stuff (node A is currently connected to nodes C and E) this would be a way of ensuring anyone that wants my Node A automatically knows its state connections. More importantly it would prevent aliasing nightmares of someone trying to pass an instance of node A with different state then the node A in my model has. I've never heard of this pattern before, and it's a bit odd. I would have to do some overriding of serialization methods to make it work (ensure that when I read in a serilized object I add it to my facotry list of known instances, and/or return an existing factory in its place), as well as using a weakHashMap as if it was a weakHashSet to know whether an instance exists without worrying about a quasi-memory leak occuring. I don't know if this is too confusing or prone to its own obscure bugs. One thing I know is that plugins interface with lowest level hardware. The plugins have to be able to return state that is different than my memory; to tell my memory when its own state is inconsistent. I believe this is possible despite their fetching objects that exist in my memory; we allow building of objects without checking their consistency with the model until the addToModel is called anyways; and the existing plugins design was written before all this extra state existed and worked fine without ever being aware of it. Should I just be using some other design to avoid this crazyness? (I have another question to that affect that I'm posting).

    Read the article

  • is a factory pattern to prevent multuple instances for same object (instance that is Equal) good design?

    - by dsollen
    I have a number of objects storing state. There are essentially two types of fields. The ones that uniquly define what the object is (what node, what edge etc), and the oens that store state describing how these things are connected (this node is connected to these edges, this edge is part of these paths) etc. My model is updating the state variables using package methdos, so these objects all act as immutable to anyone not in Model scope. All Objects extend one base type. I've toyed with the idea of a Factory approch which accepts a Builder object and construct the applicable object. However, if an instance of the object already exists (ie would return true if I created the object defined by the builder and passed it to the equal method for the existing instance) the factory returns the current object instead of creating a new instance. Because the Equal method would only compare what uniquly defines the type of object (this is node A nto node B) but won't check the dynamic state stuff (node A is currently connected to nodes C and E) this would be a way of ensuring anyone that wants my Node A automatically knows it's state connections. More importantly it would prevent aliasing nightmares of someone trying to pass an instance of node A with different state then the node A in my model has. I've never heard of this pattern before, and it's a bit odd. I would have to do some overiding of serlization methods to make it work (ensure when I read in a serilized object I add it to my facotry list of known instances, and/or return an existing factory in it's place), as well as using a weakHashMap as if it was a weakHashSet to know rather an instance exists without worrying about a quasi-memory leak occuring. I don't know if this is too confusing or prone to it's own obscure bugs. One thing I know is that plugins interface with lowest level hardware. The plugins have to be able to return state taht is different then my memory; to tell my memory when it's own state is inconsistent. I believe this is possible despit their fetching objects that exist in my memory; we allow building of objects without checking their consistency with the model until the addToModel is called anyways; and the existing plugins design was written before all this extra state existed and worked fine without ever being aware of it. Should I just be using some other design to avoid this crazyness? (I have another question to that affect I'm posting).

    Read the article

  • Client WCF DataContract has empty/null values from service

    - by Matt
    I have a simple WCF service that returns the time from the server. I've confirmed that data is being sent by checking with Fiddler. Here's the result object xml that my service sends. <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"> <s:Body> <GetTimeResponse xmlns="http://tempuri.org/"> <GetTimeResult xmlns:a="http://schemas.datacontract.org/2004/07/TestService.DataObjects" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <a:theTime>2010-03-26T09:14:38.066372-06:00</a:theTime> </GetTimeResult> </GetTimeResponse> </s:Body> </s:Envelope> So, as far as I can tell, there's nothing wrong on the server end. It's receiving requests and returning results. But on my silverlight client, all the members of the returned object are either null, blank or a default vaule. As you can see the server returns the current date and time. But in silverlight, theTime property on my object is set to 1/1/0001 12:00 AM (default value). Sooo methinks that the DataContracts do not match up between the server and the silverlight client. Here's the DataContract for the server [DataContract] public class Time { [DataMember] public DateTime theTime { get; set; } } Incredibly simple. And here's the datacontract on my silverlight client. [DataContract] public class Time { [DataMember] public DateTime theTime { get; set; } } Literally the only difference is the namespaces within the application. But still the values being returned are null, empty or a .NET default. Thanks for you help!

    Read the article

  • IoC - Dynamic Composition of object instances

    - by Joshua Starner
    Is there a way using IoC, MEF [Imports], or another DI solution to compose dependencies on the fly at object creation time instead of during composition time? Here's my current thought. If you have an instance of an object that raises events, but you are not creating the object once and saving it in memory, you have to register the event handlers every time the object is created. As far as I can tell, most IoC containers require you to register all of the classes used in composition and call Compose() to make it hook up all the dependencies. I think this may be horrible design (I'm dealing with a legacy system here) to do this due to the overhead of object creation, dependency injection, etc... but I was wondering if it was possible using one of the emergent IoC technologies. Maybe I have some terminology mixed up, but my goal is to avoid writing a framework to "hook up all the events" on an instance of an object, and use something like MEF to [Export] handlers (dependencies) that adhere to a very specific interface and [ImportMany] them into an object instance so my exports get called if the assemblies are there when the application starts. So maybe all of the objects could still be composed when the application starts, but I want the system to find and call all of them as the object is created and destroyed.

    Read the article

  • Two Way Data Binding With a Object in WPF,Image Control

    - by Candy
    Sorry, my English is not very good, I have a object "Stuffs" "Stuffs" have a Property “Icon” now: xaml <Button Click="Button_Click"><Image Width="80" Height="80" Source="{Binding Path=Icon,Converter={StaticResource ImageConverter}}"/></Button> cs private void Button_Click(object sender, RoutedEventArgs e) { IconFloder.Title = "Icon"; String IconFloderPath = AppDomain.CurrentDomain.BaseDirectory + ItemIconFloder; if (!System.IO.Directory.Exists(IconFloderPath)) System.IO.Directory.CreateDirectory(IconFloderPath); IconFloder.InitialDirectory = IconFloderPath; IconFloder.Filter = "Image File|*.jpeg"; IconFloder.ValidateNames = true; IconFloder.CheckPathExists = true; IconFloder.CheckFileExists = true; if (IconFloder.ShowDialog() == true) { HideImage.Text = ItemIconFloder + "\\" + IconFloder.SafeFileName; ((sender as Button).Content as Image).Source = new ImageConverter().Convert(ItemIconFloder + "\\" + IconFloder.SafeFileName, Type.GetType("System.Windows.Media.ImageSource"), null, new System.Globalization.CultureInfo("en-US")) as ImageSource; } } class ImageConverter:IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { if (value is string&&!String.IsNullOrEmpty(value.ToString())) { try { return new BitmapImage(new Uri(AppDomain.CurrentDomain.BaseDirectory + value)); } catch { } } return null; } public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } } I would like to click buttons, change the picture, Also change Data Binding Stuffs.Icon But failed,I have no idea?I need help? I do not know whether I speak clearly

    Read the article

  • Validation with State Pattern for Multi-Page Forms in ASP.NET

    - by philrabin
    I'm trying to implement the state pattern for a multi-page registration form. The data on each page will be accumulated and stored in a session object. Should validation (including service layer calls to the DB) occur on the page level or inside each state class? In other words, should the concrete implementation of IState be concerned with the validation or should it be given a fully populated and valid object? See "EmptyFormState" class below: namespace Example { public class Registrar { private readonly IState formEmptyState; private readonly IState baseInformationComplete; public RegistrarSessionData RegistrarSessionData { get; set;} public Registrar() { RegistrarSessionData = new RegistrarSessionData(); formEmptyState = new EmptyFormState(this); baseInformationComplete = new BasicInfoCompleteState(this); State = formEmptyState; } public IState State { get; set; } public void SubmitData(RegistrarSessionData data) { State.SubmitData(data); } public void ProceedToNextStep() { State.ProceedToNextStep(); } } //actual data stored in the session //to be populated by page public class RegistrarSessionData { public string FirstName { get; set; } public string LastName { get; set; } //will include values of all 4 forms } //State Interface public interface IState { void SubmitData(RegistrarSessionData data); void ProceedToNextStep(); } //Concrete implementation of IState //Beginning state - no data public class EmptyFormState : IState { private readonly Registrar registrar; public EmptyFormState(Registrar registrar) { this.registrar = registrar; } public void SubmitData(RegistrarSessionData data) { //Should Validation occur here? //Should each state object contain a validation class? (IValidator ?) //Should this throw an exception? } public void ProceedToNextStep() { registrar.State = new BasicInfoCompleteState(registrar); } } //Next step, will have 4 in total public class BasicInfoCompleteState : IState { private readonly Registrar registrar; public BasicInfoCompleteState(Registrar registrar) { this.registrar = registrar; } public void SubmitData(RegistrarSessionData data) { //etc } public void ProceedToNextStep() { //etc } } }

    Read the article

  • Why can't I build this Javascript object?

    - by Alex Mcp
    I have an object I'm trying to populate from another object (that is, iterate over a return object to produce an object with only selected values from the original). My code looks like this: var collect = {}; function getHistoricalData(username){ $.getJSON("http://url/" + username + ".json?params", function(data){ for (var i=0; i < data.length; i++) { console.log(i); collect = { i : {text : data[i].text}}; $("#wrap").append("<span>" + data[i].text + "</span><br />"); }; console.log(collect); }); } So I'm using Firebug for debugging, and here's what I know: The JSON object is intact console.log(i); is showing the numbers 1-20 as expected When I log the collect object at the end, it's structure is this: var collect = { i : {text : "the last iteration's text"}}; So the incrementer is "applying" to the data[i].text and returning the text value, but it's not doing what I expected, which is create a new member of the collect object; it's just overwriting collect.i 20 times and leaving me with the last value. Is there a different syntax I need to be using for assigning object members? I tried collect.i.text = and collect[i].text = and the error was that whatever I tried was undefined. I'd love to know what's going on here, so the more in-depth an explanation the better. Thanks!

    Read the article

< Previous Page | 104 105 106 107 108 109 110 111 112 113 114 115  | Next Page >