Window

Window is a top-level ContentControl.

You will not usually create instances of the Window class directly; instead the Window class is usually sub-classed for each type of window to be shown by an application.

Common Properties

Property	Description
Title	The window title
Icon	The window icon
SizeToContent	Describes the window's auto-sizing behavior
WindowState	The minimized/maximized state of the window

Show, hide and close a window

You can show a window using the Show method:

var window = new MyWindow();
window.Show();

Windows can be closed using the Close method. This has the same effect as when a user clicks the window's close button:

window.Close();

// A closed window cannot be shown.
window.Show();

Note that once a window has been closed, it cannot be shown again. If you want to re-show the window then you should use the Hide method:

window.Hide();

// Window can now be shown again later
window.Show();

See also Prevent a window from closing

Show a window as a dialog

You can show a window as a modal dialog by calling the ShowDialog method. ShowDialog requires an owner window to be passed:

// Here we assume this code is executed from our current Window class and "this" object is a Window.
// Alternatively you can get global MainWindow from Application.ApplicationLifetime casted to IClassicDesktopStyleApplicationLifetime.
var ownerWindow = this;
var window = new MyWindow();
window.ShowDialog(ownerWindow);

The ShowDialog method will return immediately. If you want to wait for the dialog to be closed, you can await the call:

var window = new MyWindow();
await window.ShowDialog(ownerWindow);

Dialogs can return a result by calling the Close method with an object. This result can then be read by the caller of ShowDialog. For example:

public class MyDialog : Window
{
    public MyDialog()
    {
        InitializeComponent();
    }

    private void OkButton_Click(object sender, EventArgs e)
    {
        Close("OK Clicked!");
    }
}

var dialog = new MyDialog();

// The result is a string so call `ShowDialog<string>`.
var result = await dialog.ShowDialog<string>(ownerWindow);

Prevent a window from closing

A window can be prevented from closing by handling the Closing event and setting e.Cancel = true:

window.Closing += (s, e) =>
{
    e.Cancel = true;
};

You could also hide the window instead. This allows the window to be re-shown after the user clicks the close button:

window.Closing += (s, e) =>
{
    ((Window)s).Hide();
    e.Cancel = true;
};

Source code

Window.cs

Additional Resources

• The Main Window