Search Results

Search found 68762 results on 2751 pages for 'data transfer objects'.

Page 172/2751 | < Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >

  • Is a red-black tree my ideal data structure?

    - by Hugo van der Sanden
    I have a collection of items (big rationals) that I'll be processing. In each case, processing will consist of removing the smallest item in the collection, doing some work, and then adding 0-2 new items (which will always be larger than the removed item). The collection will be initialised with one item, and work will continue until it is empty. I'm not sure what size the collection is likely to reach, but I'd expect in the range 1M-100M items. I will not need to locate any item other than the smallest. I'm currently planning to use a red-black tree, possibly tweaked to keep a pointer to the smallest item. However I've never used one before, and I'm unsure whether my pattern of use fits its characteristics well. 1) Is there a danger the pattern of deletion from the left + random insertion will affect performance, eg by requiring a significantly higher number of rotations than random deletion would? Or will delete and insert operations still be O(log n) with this pattern of use? 2) Would some other data structure give me better performance, either because of the deletion pattern or taking advantage of the fact I only ever need to find the smallest item? Update: glad I asked, the binary heap is clearly a better solution for this case, and as promised turned out to be very easy to implement. Hugo

    Read the article

  • What is a data structure for quickly finding non-empty intersections of a list of sets?

    - by Andrey Fedorov
    I have a set of N items, which are sets of integers, let's assume it's ordered and call it I[1..N]. Given a candidate set, I need to find the subset of I which have non-empty intersections with the candidate. So, for example, if: I = [{1,2}, {2,3}, {4,5}] I'm looking to define valid_items(items, candidate), such that: valid_items(I, {1}) == {1} valid_items(I, {2}) == {1, 2} valid_items(I, {3,4}) == {2, 3} I'm trying to optimize for one given set I and a variable candidate sets. Currently I am doing this by caching items_containing[n] = {the sets which contain n}. In the above example, that would be: items_containing = [{}, {1}, {1,2}, {2}, {3}, {3}] That is, 0 is contained in no items, 1 is contained in item 1, 2 is contained in itmes 1 and 2, 2 is contained in item 2, 3 is contained in item 2, and 4 and 5 are contained in item 3. That way, I can define valid_items(I, candidate) = union(items_containing[n] for n in candidate). Is there any more efficient data structure (of a reasonable size) for caching the result of this union? The obvious example of space 2^N is not acceptable, but N or N*log(N) would be.

    Read the article

  • Sql Exception: Error converting data type numeric to numeric

    - by Lucifer
    Hello We have a very strange issue with a database that has been moved from staging to production. The first time the database was moved it was by detaching, copying and reattaching, the second time we tried restoring from a backup of the staging. Both SQL Servers are the same version of MS SQL 2008, running on 64 bit hardware. The code accessing the database is the same build, built using the .net 2.0 framework. Here is the error message and some of the stack trace: Exception Details: System.Data.SqlClient.SqlException: Error converting data type numeric to numeric. Stack Trace: [SqlException (0x80131904): Error converting data type numeric to numeric.] System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1953274 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4849707 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2392 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +204 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +175 System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +137 Version Information: Microsoft .NET Framework Version:2.0.50727.4200; ASP.NET Version:2.0.50727.4016

    Read the article

  • Fetching Core Data for Tableview on iPhone - Tutorial leaves me with crashes when adding items to a

    - by Gordon Fontenot
    Been following the Core Data tutorial on Apple's developer site, and all is good until I have to add something to the fetched store. I am getting this error after a successful build and load when I try to add a new item to the list: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (0) must be equal to the number of rows contained in that section before the update (0), plus or minus the number of rows inserted or deleted from that section (1 inserted, 0 deleted). Due to the fact that the fetch goes through fine, and that if I replace the fetching with eventList = [[NSMutableArray alloc] init] it works as expected (without persistance, of course), I am led to believe that the problem comes from not creating the Mutable Array correctly. Here's the problematic part of the code: NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:managedObjectContext]; [request setEntity:entity]; NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"creationDate" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptors release]; [sortDescriptor release]; NSError *error; NSMutableArray *mutableFetchResults = [[managedObjectContext executeFetchRequest:request error:&error] mutableCopy]; if (mutableFetchResults = nil) { //Handle the error } [self setEventList:mutableFetchResults]; [mutableFetchResults release]; [request release]; I have tried switching the NSArrays in the second chunk out with NSMutableArrays, but I still get the same error. For reference, the section of code that is throwing the error when I try adding an entry is here: [eventList insertObject:event atIndex:0]; NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0]; [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES]; it errors out at the insertRowsAtIndexPaths call. Thanks in advance for any help

    Read the article

  • Add objects to Arraylist inside loop and get a list of them outside loops

    - by AgusDG
    Im already done with a method to do a shot on a board (bidimensional array). THe shot goes from the bottom to the top, and depending of the direction, it do bounces on the walls to get to the top. The thing is that I did the method to represent the trayectory with an 'x'. Now, I want to add the coordinates x and y of each position of the shot (b [x][y]) to and Arraylist of Objects Position. public Position(int row,int col) { this.row = row; this.col = col; } The thing is that the method uses a for loop and inside if loops, and I'll need to create the objects inside, and get them outside. I did that : public static ArrayList<Position> showTrayectory (char [][] b , int shotDirection, char bubble){ int row = 0, col = 0; ArrayList<Position> aListPos = new ArrayList<Position>(); Position positionsOfShot = new Position(row,col); START = ((RIGHT_WALL)/2) + shotDirection; boolean shotRight = false; if(shotDirection < 0) shotRight = false; else if(shotDirection > 0) shotRight = true; for(int y = BOTTOM,x = START ;y >= 0;y--) { if(!isOut(y,x) && !emptyCell(y,x)) break; if(x <= LEFT_WALL) shotRight = true; if(x >= RIGHT_WALL) shotRight = false; if(!isOut(y,x) && shotRight == true) { positionsOfShot = new Position(y,x); aListPos.add(positionsOfShot); b[y][x] = SHOT; ++x; } if(!isOut(y,x) && shotRight == false){ positionsOfShot = new Position(y,x); aListPos.add(positionsOfShot); b[y][x] = SHOT; --x; } } // The nested for loops below are for showing the positions // But I dont need it that way // I must get the trayectory from an ArrayList and print it from there for(int y=0;y < b.length;y++){ System.out.println(); for(int x=0;x < b[y].length;x++){ System.out.print(" "+b [y][x]+" "); } } System.out.println("\nTrayectory of the shot ["+shotDirection+"]"); System.out.println("Next bubble ["+bubble+"]"); for( Position ii : aListPos){ System.out.println("(" + positionsOfShot.getFila() + "," + positionsOfShot.getColumna()+")"); } return aListPos; } The sentence " b[y][x] = SHOT; " is still there, to see the proper trayectory of the shot (its not needed that way), but what I need, is getting the trayectory in an ArrayList, and print the trayectory from there. All that I get is a wrong position, and repeated during the number of positions the shot goes through. I need some help. I suppose the problem is that Im creating and adding Position Objects inside an ArrayList inside loops, but in a wrong way. I will need you to explain me how to do it properly ; ) Thanks in advance. I'll add the output for you see better what is that above haha *************************** y b y b g r b g o y g a a r y o y y r b y g r r o b o y y g b a r y r o a y y o o r r g r - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - - - x - - - - - - - x - - - - - - - x - - - - - - - x - - - Trayectory of the shot [1] Next bubble [y] (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) (5,3) Action?

    Read the article

  • How to stop Android GPS using "Mobile data"

    - by prepbgg
    My app requests location updates with "minTime" set to 2 seconds. When "Mobile data" is switched on (in the phone's settings) and GPS is enabled the app uses "mobile data" at between 5 and 10 megabytes per hour. This is recorded in the ICS "Data usage" screen as usage by "Android OS". In an attempt to prevent this I have unticked Settings-"Location services"-"Google's location service". Does this refer to Assisted GPS, or is it something more than that? Whatever it is, it seems to make no difference to my app's internet access. As further confirmation that it is the GPS usage by my app that is causing the mobile data access I have observed that the internet data activity indicator on the status bar shows activity when and only when the GPS indicator is present. The only way to prevent this mobile data usage seems to be to switch "Mobile data" off, and GPS accuracy seems to be almost as good without the support of mobile data. However, it is obviously unsatisfactory to have to switch mobile data off. The only permissions in the Manifest are "android.permission.ACCESS_FINE_LOCATION" (and "android.permission.WRITE_EXTERNAL_STORAGE"), so the app has no explicit permission to use internet data. The LocationManager code is ` criteria.setAccuracy(Criteria.ACCURACY_FINE); criteria.setSpeedRequired(false); criteria.setAltitudeRequired(false); criteria.setBearingRequired(true); criteria.setCostAllowed(false); criteria.setPowerRequirement(Criteria.NO_REQUIREMENT); bestProvider = lm.getBestProvider(criteria, true); if (bestProvider != null) { lm.requestLocationUpdates(bestProvider, gpsMinTime, gpsMinDistance, this); ` The reference for LocationManager.getBestProvider says If no provider meets the criteria, the criteria are loosened ... Note that the requirement on monetary cost is not removed in this process. However, despite setting setCostAllowed to false the app still incurs a potential monetary cost. What else can I do to prevent the app from using mobile data?

    Read the article

  • Store the cache data locally

    - by Lu Lu
    Hello, I develops a C# Winform application, it is a client and connect to web service to get data. The data returned by webservice is a DataTable. Client will display it on a DataGridView. My problem is that: Client will take more time to get all data from server (web service is not local with client). So I must to use a thread to get data. This is my model: Client create a thread to get data - thread complete and send event to client - client display data on datagridview on a form. However, when user closes the form, user can open this form in another time, and client must get data again. This solution will cause the client slowly. So, I think about a cached data: Client <---get/add/edit/delete--- Cached Data ---get/add/edit/delete---Server (web service) Please give me some suggestions. Example: cached data should be developed in another application which is same host with client? Or cached data is running in client. Please give me some techniques to implement this solution. If having any examples, please give me. Thanks.

    Read the article

  • Using Comparable to compare objects and sorting them in a TreeMap

    - by arjacsoh
    II cannot understand how should the natural ordering of class be "consistent with equals" when implementing the Comparable interface. I deteted a flaw in my program and therefore I deteced that in the documentantion of the interface Comparable. My problem is that although two Objects are considered as distinct on the base of equals method, the TreeMap structure treats them as equal and consequently does not accept the second insert. The sample code is: public class Car implements Comparable<Car> { int weight; String name; public Car(int w, String n) { weight=w; name=n; } public boolean equals(Object o){ if(o instanceof Car){ Car d = (Car)o; return ((d.name.equals(name)) && (d.weight==weight)); } return false; } public int hashCode(){ return weight/2 + 17; } public String toString(){ return "I am " +name+ " !!!"; } public int compareTo(Car d){ if(this.weight>d.weight) return 1; else if(this.weight<d.weight) return -1; else return 0; } /*public int compareTo(Car d){ return this.name.compareTo(d.name); }*/ } public static void main(String[] args) { Car d1 = new Car(100, "a"); Car d2 = new Car(110, "b"); Car d3 = new Car(110, "c"); Car d4 = new Car(100, "a"); Map<Car, Integer> m = new HashMap<Car, Integer>(); m.put(d1, 1); m.put(d2, 2); m.put(d3, 3); m.put(d4, 16); for(Map.Entry<Car, Integer> me : m.entrySet()) System.out.println(me.getKey().toString() + " " +me.getValue()); TreeMap<Car, Integer> tm = new TreeMap<Car, Integer>(m); System.out.println("After Sorting: "); for(Map.Entry<Car, Integer> me : tm.entrySet()) System.out.println(me.getKey().toString() + " " +me.getValue()); } The output is : I am a !!! 16 I am c !!! 3 I am b !!! 2 After Sorting: I am a !!! 16 I am c !!! 2 That is, that the object c has replaced (somewhat) object b. If I comment the original equals method and uncomment the second equals method, which compares the objects according name, the output is the expected: I am a !!! 16 I am c !!! 3 I am b !!! 2 After Sorting: I am a !!! 16 I am b !!! 2 I am c !!! 3 Why does it come around in this way and what should I alter in order to insert and sort different objects with some attributes of equal value in a TreeMap?

    Read the article

  • jquery fail to retrieve accurate data from sibling field.

    - by i need help
    wonder what's wrong <table id=tblDomainVersion> <tr> <td>Version</td> <td>No of sites</td> </tr> <tr> <td class=clsversion>1.25</td> <td><a id=expanddomain>3 sites</a><span id=spanshowall></span></td> </tr> <tr> <td class=clsversion>1.37</td> <td><a id=expanddomain>7 sites</a><span id=spanshowall></span></td> </tr> </table> $('#expanddomain').click(function() { //the siblings result incorrect //select first row will work //select second row will no response var versionforselected= $('#expanddomain').parent().siblings("td.clsversion").text(); alert(versionforselected); $.ajax({ url: "ajaxquery.php", type: "POST", data: 'version='+versionforselected, timeout: 900000, success: function(output) { output= jQuery.trim(output); $('#spanshowall').html(output); }, }); });

    Read the article

  • Is there a more memory efficient way to search through a Core Data database?

    - by Kristian K
    I need to see if an object that I have obtained from a CSV file with a unique identifier exists in my Core Data Database, and this is the code I deemed suitable for this task: NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription *entity; entity = [NSEntityDescription entityForName:@"ICD9" inManagedObjectContext:passedContext]; [fetchRequest setEntity:entity]; NSPredicate *pred = [NSPredicate predicateWithFormat:@"uniqueID like %@", uniqueIdentifier]; [fetchRequest setPredicate:pred]; NSError *err; NSArray* icd9s = [passedContext executeFetchRequest:fetchRequest error:&err]; [fetchRequest release]; if ([icd9s count] > 0) { for (int i = 0; i < [icd9s count]; i++) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init]; NSString *name = [[icd9s objectAtIndex:i] valueForKey:@"uniqueID"]; if ([name caseInsensitiveCompare:uniqueIdentifier] == NSOrderedSame && name != nil) { [pool release]; return [icd9s objectAtIndex:i]; } [pool release]; } } return nil; After more thorough testing it appears that this code is responsible for a huge amount of leaking in the app I'm writing (it crashes on a 3GS before making it 20 percent through the 1459 items). I feel like this isn't the most efficient way to do this, any suggestions for a more memory efficient way? Thanks in advance!

    Read the article

  • How can I synchronize one set of data with another?

    - by RenderIn
    I have an old database and a new database. The old records were converted to the new database recently. All our old applications continue to point to the old database, but the new applications point to the new database. Currently the old database is the only one being updated, so throughout the day the new database becomes out of sync. It is acceptable for the new database to be out of sync for a day, so until all our applications are pointed to the new database I just need to write a nightly cron job that will bring it up to date. I do not want to purge the new database and run the complete conversion script each night, as that would reduce uptime and would create a mess in our auditing of that table. I'm thinking about selecting all the data from the old database, converting it to the new database structure in memory, and then checking for the existence of each record before inserting it in the new database. After that's done, I'd select everything from the new database and check if it exists in the old one, and if not delete it. Is this the simplest way to do this?

    Read the article

  • Silverlight 4 caching issue?

    - by DavidS
    I am currently experiencing a weird caching problem it would seem. When I load my data intially, I return all the data within given dates and my graph looks as follows: Then I filter the data to return a subset of the original data for the same date range (not that it matters) and I get the following view of my data: However, I intermittently get the following when I refresh the same filterd view of the data: One can see that not all the data gets cached but only some of it i.e. for 12 Dec 2010 and 5 dec 2010(not shown here). I've looked at my queries and the correct data is getting pulled out. It is only on the presentation layer i.e. on Mainpage.xaml.cs that this erroneous data seems to exist. I've stepped through the code and the data is corect through all the layers except on the presentation layer. Has anyone experienced this before? Is there some sort of caching going in the background that is keeping that data in the background as I've got browser caching off? I am using the LoadOperation in the callback method within the Load method of the DomainContext if that helps...

    Read the article

  • What JavaScript object copy function works with greasemonkey?

    - by Geo
    I know there is another question related to copying objects in JavaScript here, but the code they provide does not work with greasemonkey. From what I was able to trace, the code for the accepted answer dies/ stops at the line : var temp = new obj.constructor(); Is there any way to see what went wrong ? It's not really necessary I use the same function for the object copying, but I would like something that works. Do you know some function?

    Read the article

  • How to detect if a LINQ enumeration is materialized?

    - by Peter Lillevold
    Is there some way of detecting whether an enumerable built using LINQ (to Objects in this case) have been materialized or not? Other than trying to inspect the type of the underlying collection? Specifically, since enumerable.ToArray() will build a new array even if the underlying collection already is an array I'm looking for a way of avoiding ToArray() being called twice on the same collection.

    Read the article

  • VB.NET Use With keyword on existing object?

    - by ropstah
    Is it somehow possible to use the 'With' keyword on an existing object? I would like to do the following using LINQ to objects and can't seem to find a way: From m as Product in Me _ Select m With {.Match = m.Name.IndexOf(query)} _ Where m.Name.IndexOf(query) > 0

    Read the article

  • How to recover deleted files on ext3 fs

    - by Mike
    I have a drive which was using the ext3 filesystem. I am told that about 10Gb of data was deleted off the drive (probably via rm). The drive is currently mounted as read-only to preserve all data. Does anyone know of a method to restore some or all of the data? Also if it helps, the OS was Fedora. I've also been told that the data is mostly ASCII fortan source code and Matlab files. Conclusion I have finally managed to get the data back, and with the simplest means ever! After weeks of trying and failing to bring back much of any data, I brought someone in today to take a look at it and offer suggestions, he simply cd'd to the directory and everything was there! It was never lost in the first place!!! Needless to say I feel really dumb right now, but I learned quite a lot with this whole fiasco. At any rate, while I was looking through data forensics solutions, I found that the Autopsy, or more specifically the SleuthKit was the most helpful. So I will accept that as the final answer. I would also like to note for anyone that comes across this later on that the most up-voted (currently) answer by sekenre was also helpful and I learned a lot, but ultimately it did not help with the type (very many, and some being very large) of files I was dealing with. So thank to all you that provided suggestions and wish you all the best!

    Read the article

  • Send serialised object via socket

    - by RubbleFord
    Whats the best way to format a message to a server, at moment I'm serilising an object using the binaryformatter and then sending it to the server. At the server end its listening in an async fashion and then when the buffer size recieved is not 100% it assumes that the transfer has complete. This is working and the moment, and I can deserialise the object at the other end, I'm just concerned that if I start sending async this method will fail has message's could be blurred. I know that I need to mark the message somehow as to say that's the end of message one, this other bit belongs to message 2, but I'm unsure of the correct way to do this. Could anyone point me in the right direction and maybe give me some examples? Thanks

    Read the article

  • ZFS Data Loss Scenarios

    - by Obtuse
    I'm looking toward building a largish ZFS Pool (150TB+), and I'd like to hear people experiences about data loss scenarios due to failed hardware, in particular, distinguishing between instances where just some data is lost vs. the whole filesystem (of if there even is such a distinction in ZFS). For example: let's say a vdev is lost due to a failure like an external drive enclosure losing power, or a controller card failing. From what I've read the pool should go into a faulted mode, but if the vdev is returned the pool should recover? or not? or if the vdev is partially damaged, does one lose the whole pool, some files, etc.? What happens if a ZIL device fails? Or just one of several ZILs? Truly any and all anecdotes or hypothetical scenarios backed by deep technical knowledge are appreciated! Thanks! Update: We're doing this on the cheap since we are a small business (9 people or so) but we generate a fair amount of imaging data. The data is mostly smallish files, by my count about 500k files per TB. The data is important but not uber-critical. We are planning to use the ZFS pool to mirror 48TB "live" data array (in use for 3 years or so), and use the the rest of the storage for 'archived' data. The pool will be shared using NFS. The rack is supposedly on a building backup generator line, and we have two APC UPSes capable of powering the rack at full load for 5 mins or so.

    Read the article

  • Intersection() and Except() is too slow with large collections of custom objects

    - by Theo
    I am importing data from another database. My process is importing data from a remote DB into a List<DataModel> named remoteData and also importing data from the local DB into a List<DataModel> named localData. I am then using LINQ to create a list of records that are different so that I can update the local DB to match the data pulled from remote DB. Like this: var outdatedData = this.localData.Intersect(this.remoteData, new OutdatedDataComparer()).ToList(); I am then using LINQ to create a list of records that no longer exist in remoteData, but do exist in localData, so that I delete them from local database. Like this: var oldData = this.localData.Except(this.remoteData, new MatchingDataComparer()).ToList(); I am then using LINQ to do the opposite of the above to add the new data to the local database. Like this: var newData = this.remoteData.Except(this.localData, new MatchingDataComparer()).ToList(); Each collection imports about 70k records, and each of the 3 LINQ operation take between 5 - 10 minutes to complete. How can I make this faster? Here is the object the collections are using: internal class DataModel { public string Key1{ get; set; } public string Key2{ get; set; } public string Value1{ get; set; } public string Value2{ get; set; } public byte? Value3{ get; set; } } The comparer used to check for outdated records: class OutdatedDataComparer : IEqualityComparer<DataModel> { public bool Equals(DataModel x, DataModel y) { var e = string.Equals(x.Key1, y.Key1) && string.Equals(x.Key2, y.Key2) && ( !string.Equals(x.Value1, y.Value1) || !string.Equals(x.Value2, y.Value2) || x.Value3 != y.Value3 ); return e; } public int GetHashCode(DataModel obj) { return 0; } } The comparer used to find old and new records: internal class MatchingDataComparer : IEqualityComparer<DataModel> { public bool Equals(DataModel x, DataModel y) { return string.Equals(x.Key1, y.Key1) && string.Equals(x.Key2, y.Key2); } public int GetHashCode(DataModel obj) { return 0; } }

    Read the article

  • Building an ASP.Net 4.5 Web forms application - part 4

    - by nikolaosk
    ?his is the fourth post in a series of posts on how to design and implement an ASP.Net 4.5 Web Forms store that sells posters on line.There are 3 more posts in this series of posts.Please make sure you read them first.You can find the first post here. You can find the second post here. You can find the third post here.  In this new post we will build on the previous posts and we will demonstrate how to display the posters per category.We will add a ListView control on the PosterList.aspx and will bind data from the database. We will use the various templates.Then we will write code in the PosterList.aspx.cs to fetch data from the database.1) Launch Visual Studio and open your solution where your project lives2) Open the PosterList.aspx page. We will add some markup in this page. Have a look at the code below  <section class="posters-featured">                    <ul>                         <asp:ListView ID="posterList" runat="server"                            DataKeyNames="PosterID"                            GroupItemCount="3" ItemType="PostersOnLine.DAL.Poster" SelectMethod="GetPosters">                            <EmptyDataTemplate>                                      <table id="Table1" runat="server">                                            <tr>                                                  <td>We have no data.</td>                                            </tr>                                     </table>                              </EmptyDataTemplate>                              <EmptyItemTemplate>                                     <td id="Td1" runat="server" />                              </EmptyItemTemplate>                              <GroupTemplate>                                    <tr ID="itemPlaceholderContainer" runat="server">                                          <td ID="itemPlaceholder" runat="server"></td>                                    </tr>                              </GroupTemplate>                              <ItemTemplate>                                    <td id="Td2" runat="server">                                          <table>                                                <tr>                                                      <td>&nbsp;</td>                                                      <td>                                                <a href="PosterDetails.aspx?posterID=<%#:Item.PosterID%>">                                                    <img src="<%#:Item.PosterImgpath%>"                                                        width="100" height="75" border="1"/></a>                                             </td>                                            <td>                                                <a href="PosterDetails.aspx?posterID=<%#:Item.PosterID%>">                                                    <span class="PosterName">                                                        <%#:Item.PosterName%>                                                    </span>                                                </a>                                                            <br />                                                <span class="PosterPrice">                                                               <b>Price: </b><%#:String.Format("{0:c}", Item.PosterPrice)%>                                                </span>                                                <br />                                                        </td>                                                </tr>                                          </table>                                    </td>                              </ItemTemplate>                              <LayoutTemplate>                                    <table id="Table2" runat="server">                                          <tr id="Tr1" runat="server">                                                <td id="Td3" runat="server">                                                      <table ID="groupPlaceholderContainer" runat="server">                                                            <tr ID="groupPlaceholder" runat="server"></tr>                                                      </table>                                                </td>                                          </tr>                                          <tr id="Tr2" runat="server"><td id="Td4" runat="server"></td></tr>                                    </table>                              </LayoutTemplate>                        </asp:ListView>                    </ul>               </section>  3) We have a ListView control on the page called PosterList. I set the ItemType property to the Poster class and then the SelectMethod to the GetPosters method.  I will create this method later on.   (ItemType="PostersOnLine.DAL.Poster" SelectMethod="GetPosters")Then in the code below  I have the data-binding expression Item  available and the control becomes strongly typed.So when the user clicks on the link of the poster's category the relevant information will be displayed (photo,name and price)                                            <td>                                                <a href="PosterDetails.aspx?posterID=<%#:Item.PosterID%>">                                                    <img src="<%#:Item.PosterImgpath%>"                                                        width="100" height="75" border="1"/></a>                                             </td>4)  Now we need to write the simple method to populate the ListView control.It is called GetPosters method.The code follows   public IQueryable<Poster> GetPosters([QueryString("id")] int? PosterCatID)        {            PosterContext ctx = new PosterContext();            IQueryable<Poster> query = ctx.Posters;            if (PosterCatID.HasValue && PosterCatID > 0)            {                query = query.Where(p=>p.PosterCategoryID==PosterCatID);            }            return query;                    } This is a very simple method that returns information about posters related to the PosterCatID passed to it.I bind the value from the query string to the PosterCatID parameter at run time.This is all possible due to the QueryStringAttribute class that lives inside the System.Web.ModelBinding and gets the value of the query string variable id.5) I run my application and then click on the "Midfilders" link. Have a look at the picture below to see the results.  In the Site.css file I added some new CSS rules to make everything more presentable. .posters-featured {    width:840px;    background-color:#efefef;}.posters-featured   a:link, a:visited,    a:active, a:hover {        color: #000033;    }.posters-featured    a:hover {        background-color: #85c465;    }  6) I run the application again and this time I do not choose any category, I simply navigate to the PosterList.aspx page. I see all the posters since no query string was passed as a parameter.Have a look at the picture below   ?ake sure you place breakpoints in the code so you can see what is really going on.In the next post I will show you how to display poster details.Hope it helps!!!

    Read the article

  • In WPF: Children.Remove or Children.Clear doesn't free objects

    - by Bart Roozendaal
    I create some UIElements from code behind and was anticipating the garbage collection to clear up stuff. However, the objects are not free-ed at the time I expected it. I was expecting them to be freeed at RemoveAt(0), but they are only freed at the end of the program. How can I make the objects be freed when removed from the Children collection of the Canvas? <Window x:Class="WpfApplication1.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300" MouseDown="Window_MouseDown"> <Grid> <Canvas x:Name="main" /> </Grid> </Window> The code behind is: public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); } private void Window_MouseDown(object sender, MouseButtonEventArgs e) { if (main.Children.Count == 0) main.Children.Add(new MyControl() { Background = Brushes.Yellow, Width = 100, Height = 50 }); else main.Children.RemoveAt(0); } } public class MyControl : UserControl { ~MyControl() { Debug.WriteLine("Goodbye"); } }

    Read the article

  • [PHP] Making a good singleton registry class structure which hold your objects

    - by Saif Bechan
    I am working on a web application in PHP. I have a singleton class called registry. This class will hold all the objects i need throughout my application, such as loader classes, template classes, database, classes, etc. When an object of the registry class is created I send it an array with the classes it need to load: // Create the registry $registry = registry::singleton(); // Store those core objects $registry->storeObjects(Array('session','db','page','template','errors')); In this example I only put some of the classes, to get the basic idea. Now I have some classes in the registry that use each other. For example the 'errors' object uses the 'page' object. Now I was wondering if it is a good practice to make an instance of the registry object in the errors object. Like this; class errors{ private $registry; public function __construct(){ $this->registry = registry::singleton(); } } So there is an instance of the registry object, inside an object of the registry object. This does not sound like a good idea to me. Anyone have a suggestion how to model such a thing?

    Read the article

  • Ruby - Immutable Objects

    - by Chris Bunch
    I've got a highly multithreaded app written in Ruby that shares a few instance variables. Writes to these variables are rare (1%) while reads are very common (99%). What is the best way (either in your opinion or in the idiomatic Ruby fashion) to ensure that these threads always see the most up-to-date values involved? Here's some ideas so far that I had (although I'd like your input before I overhaul this): Have a lock that most be used before reading or writing any of these variables (from Java Concurrency in Practice). The downside of this is that it puts a lot of synchronize blocks in my code and I don't see an easy way to avoid it. Use Ruby's freeze method (see here), although it looks equally cumbersome and doesn't give me any of the synchronization benefits that the first option gives. These options both seem pretty similar but hopefully anyone out there will have a better idea (or can argue well for one of these ideas). I'd also be fine with making the objects immutable so they aren't corrupted or altered in the middle of an operation, but I don't know Ruby well enough to make the call on my own and this question seems to argue that objects are highly mutable.

    Read the article

< Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >