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

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;}

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         }

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  }}