Crystal Reportviewer in Modal Form

[EddiRae]

Hello,
I am trying to have the Crystal Reportviewer as a modal form.

I have an application that has two forms. The main form that pulls all of the data together for the Crystal Report. This is where I have the crvReport.ShowDialog().

The crvReport is the 2nd form that had the reportviewer.

The showdialog() is not working the way that I thought it would. I was thinking that it would not allow you to access any other application on the PC until you closed this form. On the contrary, I am able to move around everything.

How should I have handled this?

Thanks for your input in advance!!
Eddi Rae

[sgarv]

If I understand correctly, what you are saying is that the "modal" form displays, but you are still able to open/close/use other applications that are installed on your computer.

If so, this is typical behavior. A modal form only stops you from navigating away from that window to other windows of your own application, but will never stop you from using or navigating to other applications. Even if you open (run) your application twice and the modal form is displayed on both instances, you can still navigate from one instance to the other (using Alt-Tab for example), but not to the main window that called the modal form. Regards, Sgarv

[EddiRae]

That is okay to navigate from one to another.

My program is executed from another 3rd party application. If my program was not closed and they ran my program a 2nd time, how could I close the prior instance of my program?

This would solve my problem and the modal wouldn't matter.

Thanks!!
Eddi Rae

[jggtz]

Here's one way, try it:

1.Create a new Visual Basic project.
2.Add a Standard Module to the Project.
3.Paste the following code into the module:

      Option Explicit

      Public Const GW_HWNDPREV = 3

      Declare Function OpenIcon Lib "user32" (ByVal hwnd As Long) As Long
      Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
        (ByVal lpClassName As String, ByVal lpWindowName As String) _
         As Long
      Declare Function GetWindow Lib "user32" _
        (ByVal hwnd As Long, ByVal wCmd As Long) As Long
      Declare Function SetForegroundWindow Lib "user32" _
        (ByVal hwnd As Long) As Long

4.Paste the following code into form code module

      Private Sub Form_Load()
            If App.PrevInstance Then
               ActivatePrevInstance
            End If
         End Sub

      Sub ActivatePrevInstance()
         Dim OldTitle As String
         Dim PrevHndl As Long
         Dim result As Long

         'Save the title of the application.
         OldTitle = App.Title

         'Rename the title of this application so FindWindow
         'will not find this application instance.
         App.Title = "unwanted instance"

         'Attempt to get window handle using VB4 class name.
         PrevHndl = FindWindow("ThunderRTMain", OldTitle)

         'Check for no success.
         If PrevHndl = 0 Then
            'Attempt to get window handle using VB5 class name.
            PrevHndl = FindWindow("ThunderRT5Main", OldTitle)
         End If

         'Check if found
         If PrevHndl = 0 Then
         'Attempt to get window handle using VB6 class name
         PrevHndl = FindWindow("ThunderRT6Main", OldTitle)
         End If

         'Check if found
         If PrevHndl = 0 Then
            'No previous instance found.
            Exit Sub
         End If

         'Get handle to previous window.
         PrevHndl = GetWindow(PrevHndl, GW_HWNDPREV)

         'Restore the program.
         result = OpenIcon(PrevHndl)

         'Activate the application.
         result = SetForegroundWindow(PrevHndl)

         'End the application.
         Unload Me
      End Sub

5.Compile the project into an EXE.
6.Exit Visual Basic.
7.Run the executable you created.
8.Repeat step 7.

RESULT: The first instance of the program is given focus and the second instance is closed. If the first instance of the application was minimized, it will be restored to a normal window automatically.

[EddiRae]

Thanks for the input, jggtz.

I am not able to compile. The Visual Studio 2008 is not showing the "App" as a value. Do I need to import anything to be able to use this?

[sgarv]

Here is another way:

http://www.xtremevbtalk.com/archive/.../t-203255.html

If using VB6 the App object has a PrevInstance property. I seem to recall that this method did not work for specific cases. You can try it. If it doe snot solve your problem then jggtz's method definitely will. Regards.

[jggtz]

Thanks for the input, jggtz.

I am not able to compile. The Visual Studio 2008 is not showing the "App" as a value. Do I need to import anything to be able to use this?

Sorry, I did think that You were using VB6

Then you can try:

Public Sub CheckForExistingInstance()
        'Get number of processes of you program
        If Process.GetProcessesByName _
          (Process.GetCurrentProcess.ProcessName).Length > 1 Then

       MessageBox.Show _
        ("Another Instance of this process is already running", _
            "Multiple Instances Forbidden", _
             MessageBoxButtons.OK, _
            MessageBoxIcon.Exclamation)
           Application.Exit()
        End If
    End Sub