How to catch the event of the window close button(red X button on window right top corner) in wpf form?

Question

How can I catch the event of the window close button(red X button on window right top corner) in a WPF form? We have got the closing event, window unloaded event also, but w

Answer 1

Try this:

        protected override void OnClosing(CancelEventArgs e)
        {
            this.Visibility = Visibility.Hidden;

            string msg = "Close or not?";
            MessageBoxResult result =
              MessageBox.Show(
                msg,
                "Warning",
                MessageBoxButton.YesNo,
                MessageBoxImage.Warning);
            if (result == MessageBoxResult.No)
            {
                // If user doesn't want to close, cancel closure
                e.Cancel = true;
            }
            else
            {
                e.Cancel = false;
            }
        }

Answer 2

In VB.NET:

    Private Sub frmMain_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
    ' finalize the class

    End Sub

To disable the Form X button:

'=====================================================
' Disable the X button on the control bar
'=====================================================
Private Const CP_NOCLOSE_BUTTON As Integer = &H200
Protected Overloads Overrides ReadOnly Property CreateParams() As CreateParams
    Get
        Dim myCp As CreateParams = MyBase.CreateParams
        myCp.ClassStyle = myCp.ClassStyle Or CP_NOCLOSE_BUTTON
        Return myCp
    End Get
End Property

Answer 3

Use the Closing event in the Window, you can handle it like this to prevent it from closing:

private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
    e.Cancel = true;
}

Answer 4

if it is pressed confirm button in form2 do action, if it is pressed X-button do nothing:

public class Form2
{
  public bool confirm { get; set; }

    public Form2()
        {
            confirm = false;
            InitializeComponent(); 
        }

   private void Confirm_Button_Click(object sender, RoutedEventArgs e)
    {
       //your code
       confirm = true;
       this.Close();

    }

}

first form:

public void Form2_Closing(object sender, CancelEventArgs e)
        {
            if(Form2.confirm == false) return;

            //your code 
        }

Answer 5

SOLUTION:

Have a flag to identify if Close() method is called from other than X icon button. (eg: IsNonCloseButtonClicked;)

Have a conditional statement inside Closing () event method which checks if the IsNonCloseButtonClicked is false.

If false, the app is trying to close itself through other than X icon button. If true, it means X icon button is clicked for closing this app.

[Sample Code]

private void buttonCloseTheApp_Click (object sender, RoutedEventArgs e) {
  IsNonCloseButtonClicked = true;
  this.Close (); // this will trigger the Closing () event method
}


private void MainWindow_Closing (object sender, System.ComponentModel.CancelEventArgs e) {
  if (IsNonCloseButtonClicked) {
    e.Cancel = !IsValidated ();

    // Non X button clicked - statements
    if (e.Cancel) {
      IsNonCloseButtonClicked = false; // reset the flag
      return;
    }
  } else {

    // X button clicked - statements
  }
}

Answer 6

at form1.Designer.cs put below code to assign the event

this.Closing += Window_Closing;

at form1.cs put the closing function

private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
    //change the event to avoid close form
    e.Cancel = true;
}