Cancelling the form to unload in vb .net

[lotus18]

How to cancel the unload event of a form? I have this code in vb 6 and it is working:

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
    If MsgBox("Are you sure you want to exit system?", vbYesNo, "Exit System") = vbYes Then
        Unload Me
    Else
        Cancel = 1
    End If
End Sub
 

I converted the codes to vb .net but I failed to make it:

Private Sub frmMain_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MessageBox.Show("Are you sure you want to exit system?", "Exit System", MessageBoxButtons.YesNo, MessageBoxIcon.Question) = Windows.Forms.DialogResult.Yes Then
            Global.System.Windows.Forms.Application.Exit()
        Else
Exit Sub
        End If
End Sub

Rey Sean

[Sick0Fant]

How to cancel the unload event of a form? I have this code in vb 6 and it is working:

Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
    If MsgBox("Are you sure you want to exit system?", vbYesNo, "Exit System") = vbYes Then
        Unload Me
    Else
        Cancel = 1
    End If
End Sub
 

I converted the codes to vb .net but I failed to make it:

Private Sub frmMain_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MessageBox.Show("Are you sure you want to exit system?", "Exit System", MessageBoxButtons.YesNo, MessageBoxIcon.Question) = Windows.Forms.DialogResult.Yes Then
            Global.System.Windows.Forms.Application.Exit()
        Else
Exit Sub
        End If
End Sub

Rey Sean

Use the FormClosing eventargs

If MessageBox.Show("Are you sure?", "Close?", MessageBoxButtons.YesNo) = Windows.Forms.DialogResult.No Then
      e.Cancel = True
    Else
      e.Cancel = False
    End If
 

[lotus18]

I just added this line.

e.Cancel = True

But now, the problem is, it showing the message dialog box twice when I clicked the Yes button. What may be the problem? What do you think?

Rey Sean

[Plater]

Do you have two event handlers assigned to the event?

It should also be noted that you need to be looking at the e.CloseReason property too make sure it's not CloseReason.WindowsShutDown or CloseReason.TaskManagerClosing. You should not popup your messagebox if it's one those two.