why form_closing() is firing twice? - winforms

Question

I am working on a windows form application. I want to show user a message stating close reason when user clicks "X" button in the main window.With "X" button i mean "close" button in "minimize","maximize" and "close" tray in windows.
I have written this code.
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
else
{
Application.Exit();
}
}
Now what happens is,If user clicks no to message box,event is discarded and when user clicks yes,form_closing() fires again and shows other messagebox.So messagebox is shown twice.I want to show it once.Please help and tell why is it firing twice.

Answer 1

You can skip the else part of your application. If your form is main form of application, it will exit anyway.
Application.Exit() causes all windows to close. Your "first" close is still pending, so form is not yet closed and Application.Exit() tries to close your form for the second time.
You can try this:
bool closingPending = false;
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
if (closingPending) return;
if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
else
{
closingPending = true;
Application.Exit();
}
}

Answer 2

I know this thread is a bit old, but why not:
$Application.OpenForms["NameOfMainForm"].Close;

Answer 3

I know this is old and I stumbled upon this question as I encountered the same behavior. I'm using .Net 4.5 and here is how I went about this issue:
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
if (e.CloseReason == CloseReason.UserClosing)
{
if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
else
{
Application.Exit();
}
}
}
You can find more information about CloseReason enumeration here: http://msdn.microsoft.com/en-us/library/system.windows.forms.closereason.aspx

Answer 4

Why Application.Exit in the else branch? This is done automatically and may solve your problem.

Answer 5

Private Sub ClaimEditor_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
If MsgBox("Edit mode active. Exit without saving?", MsgBoxStyle.YesNo Or MsgBoxStyle.Question, "Edit mode") <> MsgBoxResult.Yes Then
e.Cancel = True
Exit Sub
'Else
' e.Cancel = False
End If
WriteIntoRregistry()
RemoveHandler Me.FormClosing, AddressOf ClaimEditor_FormClosing
Application.Exit()
End Sub

Answer 6

I had this same issue and determined that the Application.Exit() was calling the FormClosing event.
Only put Application.Exit() in the FormClosed event, instead of the FormClosing event.
Use this code:
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
if (closingPending) return;
if (MessageBox.Show("This application is closing down because of " +
e.CloseReason.ToString () + ". Do you really want to close it ?", ""
, MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
else
{
closingPending = true;
// Application.Exit(); <-- Remove this
}
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
Application.Exit(); <-- Put it here.
}

Answer 7

I think #Tornado726 already answered the best possible answer for all. But there is just one Copy/Paste mistake I guess (typed form_closing twice)
Private Sub FORM1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
Select Case (MessageBox.Show("Do you really want to close?", "Quit", MessageBoxButtons.YesNo))
Case MsgBoxResult.No
e.Cancel = True
End Select
End Sub
Private Sub FORM1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
Application.Exit()
End Sub

Answer 8

try this: this will be a great help
private void Master_FormClosing(object sender, FormClosingEventArgs e)
{
DialogResult result = MessageBox.Show("Do you really want to exit the program?", "Data Patch", MessageBoxButtons.YesNo);
if (result != DialogResult.Yes)
{
e.Cancel = true;
}
}

Answer 9

Application.Exit() calls frmX_FormClosing().
That's why FormClosing() gets called twice.

Answer 10

I've just had that same problem. This is what I did to get around it:
private void frmIMS_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("This application is closing down because of " + e.CloseReason.ToString() + ". Do you really want to close it ?", "", MessageBoxButtons.YesNo) == DialogResult.No)
{
e.Cancel = true;
}
else
{
try
{
Environment.Exit(0); // It will try to close your program "the hard way"
}
catch (Exception)
{
Application.Exit(); // If a Win32 exception occurs, then it will be able to close your program "the normal way"
}
}
}
I'm sure it's going to work for you, if you haven't already found a solution or even given up on that code as it's been quite a while.