.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

WPF on XP : commands 'canexecute' method slow ?

Posted By:      Posted Date: September 15, 2010    Points: 0   Category :WPF
Hi, I've created an aplication with WPF. I use the command pattern (well known 'RelayCommand' implementation of ICommand, with boolean properties from INotifyPropertyChanged objects, e.g 'MyObject.HasChanges' with a custom 'Save' command to be available if HasChanges is true). The application is deployed on many computers, in different sites ; in some cases the commands seem to be too slow, or buggy : the controls like MenuItem, Button etc. on which the Command property is set can take several seconds to be updated (meaning e.g their IsEnabled property will be et to true after the CanExecute call, but after a strange delay). In all cases, the problem appears with XP ; some are SP2, others SP3 fully up-to-date via Windows Update. All have the .NET framework v.3.5 SP1, and that is regardless of the hardware performances considerations (some where I see this bug are Quad Core with 4 Go ram, and the application runs very well on some machines with Celerons and 1 Go ram...). Graphic cards can be differnts too : the problem appears with a NVidia, and with a ATI too. I tried a lot of things, including disabling AllowsTransparency, etc... Debugger can't help, I don't know what to try after that, please help ;) !If my english isn't perfect, please excuse me -- feel free to tell me.

View Complete Post

More Related Resource Links

WorkflowRuntime GetWorkflow method is slow

My application load all available workflows on startup after the user logs in. I have a list of workflows I've gotten from the SQL persistence via GetAllWorkflows(). For each of these, I try to do WorkflowRuntime.GetWorkflow. This call is taking around 220ms. Seems small, but when I'm loading 100+ workflows it isn't. The database code only seems to take around 20ms, so I wonder what all is going on that takes so long? Any pointers on loading a bunch of workflows fast?

Slow Copy Method


So I wanted to make a program where I need to Copy files. I want to trace the progress of the copy process and because in WPF + c# this is not supported I thougt I would make my own Copy Method (Signature Copy(src, dest, progressBar)) the progressbar is so it can directly update the progress of the copy process.

Here follows a piece of the code from the threaded method:


long size = new System.IO.FileInfo(source).Length;

                long currentSize = 0;



                reader = System.IO.File.OpenRead(source);


                writer = new System.IO.FileStream(destination, System.IO.FileMode.OpenOrCreate);



                int readByte;


                while ((readByte = reader.ReadByte()) > -1)




Thinking about new C# method prototypes: object as dictionary

I recently had to write a small Flickr API. I know many .Net API for Flickr already exist but I needed one for a Silverlight application. Whatever, it's only about building some querystrings so I did it by myself. It's been an opportunity to think again about a classical question: how to pass parameters to a method ?

Imagine you have a generic method to call some Flickr functions.

ASP.Net Gridview Edit Update Cancel Commands

In ASP.Net 2.0, GridView Control also provides the functionality to edit and update the data retrieved from the database using CommandField template. You can cancel the action using Cancel Command of the CommandField. GridView consists of events that can be used to perform the actions like edit, update and cancel upon the Data items displayed in the ASP.Net GridView Data Control.

Response.Redirect slow


I'm in the middle of migrating servers and on the new server Response.Redirect is extremely slow. It takes around 20 seconds for the browser to get the redirect. This is something that was quick on the existing server. It's an ASP.NET 2.0 application, both servers are running IIS6.

Additionally, if I "manually" do the redirect, it's fast. For example:

Existing way:


takes around 20 seconds on the new server

New way:

Response.Status = "302 Moved Temporarily";
Response.AddHeader("Location", url);

is fast on the new server.

Any ideas why Response.Redirect would be so slow on the new server?

Sys.Net.WebServiceFailedException: The server method '' failed with the following error:



Let's say we have 2 time consuming functions, aaa and aaa1 inside a aspx page.

        public static string aaa(int i)
            return i.ToString();

        public static string aaa1(int i)
            return i.ToString();



        <asp:ScriptManager ID="ScriptManager1" runat="server" EnablePageMethods="true">
        <span id="displayspan"></span>
        <br />
        <input type="button" value=

Jscript error: Object does not support property or method


 Hi, i have little knowledge on javascript but i need to use this code get from somewhere for a jquery to work.

I face this "Jscript runtime error: Object does not support property or method" whenever im trying to run this page.

In my experience, im get this error msg 9 out of 10 times i use javascript in my system.

Im using Microsoft Visual web developer 2008, i wonder if this is related to my problem, i not sure there is anything i need to add as reference or update anything.

But anyway, in short, i just couldn't use javascript code when using this development tool because of this sort of error.

Anyway, it happen that last time i tried use the same type of jquery code in another project and it seems to work well without an error.

But now when im try to use it again in this recent project i created, it come out with this error and i have no idea how to solve it even look through google and this forum.

It doesn't really seems like its the code problem itself although im not sure, because any javascript code just couldn't work.

So below is my code that i need to use.

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js" ></script>
<script type="text/javascript" src=&quo

VS 2010 Pro is slow



I was wondering if anybody else is finding VS 2010 extremely slow loading a solution - and it pretty much renders the rest of the machine useless until loaded. Everything is slowed to a halt.

I upgraded from VS 2005 - now I think I made a terrible mistake. I cannot afford to try and load 2 solutions simultaneously.

The machine is a Core2 Duo E8400, 3GB of RAM, WinXP SP3. Max I can go to is 4GB. Would upgrading to a 64-bit OS really be worth it (actually only to get 8GB of RAM)?

I'm hoping someone else has found a solution to this particular problem.



Using CreateNewUserWizard SendingMail method to email me, not applicatnt.


I have staff area of my site I am protecting with forms authentication using c# and .Net 4.0. What I want to do is let the staff members register on the site but instead of the confermation email being sent to them I want it sent to me so I can go in and approve it. I have been trying to use the SendingMail method  but can not figure out how to get it to email me instead of the person that registered. I have searched around this site and find many topics on the SendingMail method but none seem to properly address my issue. Can anyone help me out?

statement cannot appear outside of a method body


hi all,

  i am posting my vb.net problem .plz tell me how to resolve this :-

Dim conn As String = ConfigurationManager.ConnectionStrings("NorthwindConnectionString").ConnectionString
    'Dim mysqlconnection As New SqlConnection(conn)
    'If mysqlconnection.State=ConnectionState.closed Then mysqlconnection.Open();
    'Dim mySqlcommand As New SqlCommand("select CategoryId,CategoryName from Categories", mysqlconnection)
    'Dim mySqlDataAdapter As New SqlDataAdapter(mySqlcommand)
    'Dim mydataSet As New DataSet()

    'if mysqlconnection.State=ConnectionState.closed Then mysqlconnection.Open();

i m getting 5 errors in this code

declaration expected in mySqlDataAdapter.Fill method; Gridview1.DataSource=ds; Gridview1.DataBind();

Question in Get method in C#


I got a recent working code from client.I see errors in the get methods when i compile , below are some place where the error happens.Can any one help me out?


Error 2 'System.Environment.NewLine.get': cannot explicitly call operator or accessor C:\Documents and Settings\shankar\My Documents\Visual Studio 2008\Projects\DKCLwin\DKCLwin\LocalizationAdmin.cs 150 170 DKCLwin

Error 2 'System.Environment.NewLine.get': cannot explicitly call operator or accessor C:\Documents and Settings\shankar\My Documents\Visual Studio 2008\Projects\DKCLwin\DKCLwin\LocalizationAdmin.cs 150 170

Advanced WPF: Understanding Routed Events And Commands In WPF


See how routed events and routed commands in Windows Presentation Foundation form the basis for communication between the parts of your UI.

Brian Noyes

MSDN Magazine September 2008

Cmdlets: Extend Windows PowerShell With Custom Commands


Jim Truher presents an introduction to writing and registering your own custom cmdlets to be used in Windows PowerShell.

Jim Truher

MSDN Magazine December 2007

.NET Matters: Restart Manager and Generic Method Compilation


This month Stephen Toub answers questions pertaining to the Windows Vista Restart Manager API and generic method compilation.

Stephen Toub

MSDN Magazine April 2007

Test Run: Determining .NET Assembly and Method References


Before you can test any software system effectively, you must understand the system under test. If the system includes the Microsoft® . NET Framework, understanding the system under test includes understanding its assembly and method dependencies.

James McCaffrey

MSDN Magazine March 2006

ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend