I would like my form to be hidden when the use clicks on the window close button (the X button on the top-right corner). The e.CloseReason does not provide a value to determine that this particular button is the reason that is closing the form. This was very simple in VB6:
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer) If UnloadMode = vbFormControlMenu Then Cancel = True End If End Sub |
How is this possible in .NET Forms
form close reason
Sachin chakote
Replace the '&' with an 'And'.
Choong
http://forums.microsoft.com/msdn/ShowPost.aspx PostID=64638#64638
matt01
On .NET winforms, you can try something like this:
protected override void OnClosing(CancelEventArgs e)
{
if ( <insert your condition here> ) e.Cancel = true;
else base.OnClosing (e);
}
The e.Cancel parameter from the received event data is a boolean value where you can set to true to cancel the event.
-chris
alche
Try the following:
using System;
using System.ComponentModel;
using System.Security.Permissions;
using System.Windows.Forms;
namespace MyApplication
{
public class Form1 : Form
{
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_CLOSE = 0xF060;
private bool _UserClose;
public Form1()
{
}
protected override void OnClosing(CancelEventArgs e)
{
if (_UserClose)
{
MessageBox.Show("The user clicked the X button.");
}
base.OnClosing(e);
}
[SecurityPermission(SecurityAction.LinkDemand, UnmanagedCode = true)]
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_SYSCOMMAND && ((int)m.WParam & 65520) == SC_CLOSE)
{
_UserClose = true;
}
base.WndProc(ref m);
_UserClose = false;
}
}
}
Matt Masson
Take a look at the following code sample:
http://dotnet.mvps.org/dotnet/samples/windowsandforms/CloseWindow.zip
A simpler option using Form1_Closing Event would be to use the following: I am not sure how to detect the other options but you can find out by trial and error with this approach: * Not sure if this works - still verifying*
Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
Dim objStackFrame As StackFrame = New StackTrace(True).GetFrame(7)
If objStackFrame.GetMethod().Name = "CallWindowProc" Then
e.Cancel = True
End If
End Sub
Regards,
Vikram
Billy B
I tried to use your code David in VB.
Is the equivelant of the two constants declaration the following
Private Const WM_SYSCOMMAND As Integer = &H112
Private Const SC_CLOSE As Integer = &HF060
If so, your code works only if I make the following modification:
(int)m.WParam == SC_CLOSE)
instead of
((int)m.WParam & 65520) == SC_CLOSE)
thomastwo
Jeff Peil