WPF Discussion Boards

13-Jan-10 4:29

I am writing a WPF app that loops thru a series of windows. The first time thru, I need to create the next window, but on subsequent times, I want it to re-display the previously created window. I believe the function TryFindResource() should help me do this, but it's not working. See code below.

Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)

     Dim nextWindow As Window = CType(TryFindResource("Window3"), Window)
     If (nextWindow Is Nothing) Then
         nextWindow = New Window3
         nextWindow.Show()
     Else
         nextWindow.Show()
     End If

 End Sub

Appreciate any help with this. Yes, this is my first WPF app.

gritter13-Jan-10 4:59

13-Jan-10 4:59

I changed the line with TryFindResource() to:

Dim nextWindow As Window = CType(Application.Current.TryFindResource("Window3"), Window)

The change made no difference. It still doesn't find the existing instance of Window3.

Ian Shlasko13-Jan-10 5:52

Ian Shlasko

13-Jan-10 5:52

Try a static/shared field - These are related to the class itself, not to the instance of the class:

In the Window3 code:

Private Shared _currentInstance as Window3

Public Shared Function GetInstance() As Window3
  If _currentInstance Is Nothing Then
    _currentInstance = New Window3
  End If

 GetInstance = _currentInstance
End Function

Also, be sure to add code to the OnClosing, or some similar location, to set _currentInstance back to Nothing if you close Window3.

And in your btnGo code:

Window3.GetInstance().Show()

Oh, and might want to consider giving Window3 a more meaningful name.

Proud to have finally moved to the A-Ark. Which one are you in?
Author of Guardians of Xen (Sci-Fi/Fantasy novel)

gritter13-Jan-10 6:48

13-Jan-10 6:48

Thanks! That works, except it does shift focus to the "called window". If you can help me out here too, I would appreciate it. WPF makes me feel pretty helpless. I didn't realize it was so different from WinForms.

gritter13-Jan-10 6:58

Re: I need an ebay program

13-Jan-10 6:58

Actually I think I got. It's probably not the best way, but I can do what I need by playing with the "topmost" property.

Thanks.

I need an ebay program

totolcm13-Jan-10 2:24

totolcm

13-Jan-10 2:24

I need a program in PHP which can extract the hidden biders from ebay.I will have to insert the item number and the program must show me all bidders of the auction and their emails.
Also the same program must extract the registered contact information for any specified bidder specially the email address

I will pay for this
If someone can help please contact me at totos_back@yahoo.com

Thanks

Pete O'Hanlon13-Jan-10 3:03

13-Jan-10 3:03

totolcm wrote:
I need a program in PHP

The only thing you got right is that WPF and PHP both contain the letter P.

totolcm wrote:
I will have to insert the item number and the program must show me all bidders of the auction and their emails.
Also the same program must extract the registered contact information for any specified bidder specially the email address

There's a reason that this info is hidden by a user, and they aren't going to want it made visible by somebody else. I doubt that this functionality is possible without hacking.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Silverlight error in asp.net aplication

Amit Patel198512-Jan-10 22:37

Amit Patel1985

12-Jan-10 22:37

Hi all,

I am getting the following error in Silverlight when i integrated silverlight with my previus application this error i am not getting on every system ..

Unhandled Error in Silverlight Application An exception occurred during the operation, making the result invalid. Check InnerException for exception details

how to fix this issue.

thanks,

Amit Patel

Abhinav S12-Jan-10 23:13

Abhinav S

12-Jan-10 23:13

You will need to proved some code (or more information - silverlight verion etc) before anyone here can help you.

There are only 10 types of people in this world — those who understand binary, and those who don't.

Mark Salsbery13-Jan-10 6:49

Mark Salsbery

13-Jan-10 6:49

Did you check the InnerException for details?

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Michael Eber21-Jan-10 9:08

Michael Eber

21-Jan-10 9:08

You will basically get this error anytime you have an exception occuring in your application and you are not handling it. You need to go into debug mode and walk through your code to see what the actual exception is.

I've found that the InnerException is basically useless. You must walk through your code in debug mode.

Problem in 3D drawing for jagged line

Kunal Chowdhury «IN»23-Jan-10 23:25

Kunal Chowdhury «IN»

23-Jan-10 23:25

Good Question. This is a default behavior of Silverlight. Whenever any unhandled exception occurs in your Silverlight application you will catch it there.

Put a break point inside the App.xaml.cs file in the APP UNHANDLED EXCEPTION event. You can check there what is causing the same & if it helps you please vote for this post. Wish you all the best.

Gopal_Kanchana12-Jan-10 20:50

Gopal_Kanchana

12-Jan-10 20:50

Hi We are working CAD project. We are plahning to swith into wpf. I found some problem for appearning jagged lines in outside the cube(Not even lining) i changed resolution also. but not result.

I have seen some application which is devloped by Directx which is not appearning and looks good, not even seen jagged lines.

Why this is happening in WPF. please let me the solution

Regards
Gopal

Win7:WPF has a bug when set a button visible during system suspending or resuming. (Online Waiting) [modified]

YoYo_Yao12-Jan-10 16:02

YoYo_Yao

12-Jan-10 16:02

My WPF application need to set some buttons visibility to Visible when system suspending or resuming, but in Win7, I still can NOT see these buttons after resumed. These buttons will be shown if I move mouse on them in this case.

I think this is because system doesn't waite applications during Win7 suspending, but how can I force refresh and show my buttons after resumed?

I created a WPF demo to test this issue, only one button is the main dialog in this demo, and it also can reproduce this issue in Win7. The main code is below(In default, DemoBtn.Visibility = Hidden):

void Window1_Loaded(object sender, RoutedEventArgs e)
{
      SystemEvents.PowerModeChanged += new PowerModeChangedEventHandler(SystemEvents_PowerModeChanged);
}

private void SystemEvents_PowerModeChanged(object sender, PowerModeChangedEventArgs e)
{
      if (e.Mode == PowerModes.Suspend)
      {
            //DemoBtn.Visibility = Visibility.Visible;
      }
      else if (e.Mode == PowerModes.Resume)
      {
            DemoBtn.Visibility = Visibility.Visible;
      }
}

modified on Tuesday, January 12, 2010 10:10 PM

Re: Win7:WPF has a bug when set a button visible during system suspending or resuming. (Online Waiting)

Daniel Grunwald15-Jan-10 4:37

Daniel Grunwald

15-Jan-10 4:37

AFAIK SystemEvents are raised on a separate thread, so I'd be surprised if you could change your buttons inside the handler without getting an InvalidOperationException.

Try using Dispatcher.Invoke (as usual for cross-thread calls).

Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Mohammad Dayyan12-Jan-10 8:27

Mohammad Dayyan

12-Jan-10 8:27

Hi everybody.
I'm gonna select and expand a specific TreeViewItem in WPF's TreeView.
In WinForm Applications we could use treeView1.Nodes.Find to find a specific item in a TreeView ,
Do you know the equivalent of this method in WPF ?

Thanks.

Re: Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Pete O'Hanlon13-Jan-10 3:30

13-Jan-10 3:30

The standard way of doing this is discussed in quite some detail in this[^] article.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Re: Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Mohammad Dayyan13-Jan-10 8:33

Mohammad Dayyan

13-Jan-10 8:33

Thanks Pete O'Hanlon.
I have written a method and I posted here[^] to do that.
It works ,
What's your idea about it ?

Re: Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Pete O'Hanlon13-Jan-10 8:46

13-Jan-10 8:46

While it will work, it's not a particularly effective method and is bound very much in the way that win forms used to work. What happens though, if you apply virtualisation to the treeview?

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

Re: Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Mohammad Dayyan14-Jan-10 2:53

Mohammad Dayyan

14-Jan-10 2:53

What did you mean by virtualisation ?

Re: Equivalent of treeView1.Nodes.Find in WPF TreeView ?

Pete O'Hanlon14-Jan-10 10:47

14-Jan-10 10:47

I mean something like this[^].

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

How can I bind data from one combo box to another ?

gil eichenbaum12-Jan-10 2:47

gil eichenbaum

12-Jan-10 2:47

Hi !

I am tring to make a form which contains two combo boxes, one for country and one for city.
I have linked them to sql tables i have and used linq to sql.
I got to bind each to its table, but can't filter the cities by country.

Please help....

Re: How can I bind data from one combo box to another ?

Pete O'Hanlon12-Jan-10 3:42

12-Jan-10 3:42

You should get a good idea on how to handle this here[^].

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.