Problem
In WPF, I’m creating a modal dialog. How do I disable the close button in a WPF window? Its WindowState should still have a standard title bar, in my opinion.
I found the parameters ResizeMode, WindowState, and WindowStyle, but none of these allow me to hide the close button while displaying the title bar, like in modal dialogs.
Asked by Michael Hedgpeth
Solution #1
Although WPF lacks a built-in feature to conceal the Close button in the title bar, you can accomplish this with a few lines of P/Invoke.
To begin, make the following declarations in your Window class:
private const int GWL_STYLE = -16;
private const int WS_SYSMENU = 0x80000;
[DllImport("user32.dll", SetLastError = true)]
private static extern int GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")]
private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
Then, in the Window’s Loaded event, paste the following code:
var hwnd = new WindowInteropHelper(this).Handle;
SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) & ~WS_SYSMENU);
And there you have it: there is no longer a Close button. You won’t see a window icon on the left side of the title bar, which means you won’t see a system menu, even if you right-click the title bar – they’re all linked.
It’s important to notice that this only hides the button. The window can still be closed by the user! The window will close even if the user uses Alt+F4 or closes the app from the taskbar.
You might also override OnClosing and set Cancel to true, as Gabe mentioned, if you don’t want the window to close before the background thread is finished.
Answered by Joe White
Solution #2
I recently encountered a similar issue, and Joe White’s answer strikes me as clear and straightforward. I repurposed it and made it a Window attached property.
public class WindowBehavior
{
private static readonly Type OwnerType = typeof (WindowBehavior);
#region HideCloseButton (attached property)
public static readonly DependencyProperty HideCloseButtonProperty =
DependencyProperty.RegisterAttached(
"HideCloseButton",
typeof (bool),
OwnerType,
new FrameworkPropertyMetadata(false, new PropertyChangedCallback(HideCloseButtonChangedCallback)));
[AttachedPropertyBrowsableForType(typeof(Window))]
public static bool GetHideCloseButton(Window obj) {
return (bool)obj.GetValue(HideCloseButtonProperty);
}
[AttachedPropertyBrowsableForType(typeof(Window))]
public static void SetHideCloseButton(Window obj, bool value) {
obj.SetValue(HideCloseButtonProperty, value);
}
private static void HideCloseButtonChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var window = d as Window;
if (window == null) return;
var hideCloseButton = (bool)e.NewValue;
if (hideCloseButton && !GetIsHiddenCloseButton(window)) {
if (!window.IsLoaded) {
window.Loaded += HideWhenLoadedDelegate;
}
else {
HideCloseButton(window);
}
SetIsHiddenCloseButton(window, true);
}
else if (!hideCloseButton && GetIsHiddenCloseButton(window)) {
if (!window.IsLoaded) {
window.Loaded -= ShowWhenLoadedDelegate;
}
else {
ShowCloseButton(window);
}
SetIsHiddenCloseButton(window, false);
}
}
#region Win32 imports
private const int GWL_STYLE = -16;
private const int WS_SYSMENU = 0x80000;
[DllImport("user32.dll", SetLastError = true)]
private static extern int GetWindowLong(IntPtr hWnd, int nIndex);
[DllImport("user32.dll")]
private static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
#endregion
private static readonly RoutedEventHandler HideWhenLoadedDelegate = (sender, args) => {
if (sender is Window == false) return;
var w = (Window)sender;
HideCloseButton(w);
w.Loaded -= HideWhenLoadedDelegate;
};
private static readonly RoutedEventHandler ShowWhenLoadedDelegate = (sender, args) => {
if (sender is Window == false) return;
var w = (Window)sender;
ShowCloseButton(w);
w.Loaded -= ShowWhenLoadedDelegate;
};
private static void HideCloseButton(Window w) {
var hwnd = new WindowInteropHelper(w).Handle;
SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) & ~WS_SYSMENU);
}
private static void ShowCloseButton(Window w) {
var hwnd = new WindowInteropHelper(w).Handle;
SetWindowLong(hwnd, GWL_STYLE, GetWindowLong(hwnd, GWL_STYLE) | WS_SYSMENU);
}
#endregion
#region IsHiddenCloseButton (readonly attached property)
private static readonly DependencyPropertyKey IsHiddenCloseButtonKey =
DependencyProperty.RegisterAttachedReadOnly(
"IsHiddenCloseButton",
typeof (bool),
OwnerType,
new FrameworkPropertyMetadata(false));
public static readonly DependencyProperty IsHiddenCloseButtonProperty =
IsHiddenCloseButtonKey.DependencyProperty;
[AttachedPropertyBrowsableForType(typeof(Window))]
public static bool GetIsHiddenCloseButton(Window obj) {
return (bool)obj.GetValue(IsHiddenCloseButtonProperty);
}
private static void SetIsHiddenCloseButton(Window obj, bool value) {
obj.SetValue(IsHiddenCloseButtonKey, value);
}
#endregion
}
Then you just set it up in XAML like this:
<Window
x:Class="WafClient.Presentation.Views.SampleWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:u="clr-namespace:WafClient.Presentation.Behaviors"
ResizeMode="NoResize"
u:WindowBehavior.HideCloseButton="True">
...
</Window>
Answered by SpudCZ
Solution #3
Set the WindowStyle property to None to make the control box and title bar disappear. There’s no need to kernal your calls.
Answered by Sriwantha Attanayake
Solution #4
This won’t make the close button disappear, but it will prevent someone from closing the window.
Include the following in your code behind file:
protected override void OnClosing(CancelEventArgs e)
{
base.OnClosing(e);
e.Cancel = true;
}
Answered by flurbius
Solution #5
You should add the following code to your Window class to deactivate the close button (the code was obtained from here, altered, and reformatted a little):
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
HwndSource hwndSource = PresentationSource.FromVisual(this) as HwndSource;
if (hwndSource != null)
{
hwndSource.AddHook(HwndSourceHook);
}
}
private bool allowClosing = false;
[DllImport("user32.dll")]
private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
[DllImport("user32.dll")]
private static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);
private const uint MF_BYCOMMAND = 0x00000000;
private const uint MF_GRAYED = 0x00000001;
private const uint SC_CLOSE = 0xF060;
private const int WM_SHOWWINDOW = 0x00000018;
private const int WM_CLOSE = 0x10;
private IntPtr HwndSourceHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
switch (msg)
{
case WM_SHOWWINDOW:
{
IntPtr hMenu = GetSystemMenu(hwnd, false);
if (hMenu != IntPtr.Zero)
{
EnableMenuItem(hMenu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
}
}
break;
case WM_CLOSE:
if (!allowClosing)
{
handled = true;
}
break;
}
return IntPtr.Zero;
}
This code also disables the close item in the System menu, as well as the use of Alt+F4 to close the dialog.
You’ll probably want to programmatically close the window. It’s not enough to simply call Close(). Do something along these lines:
allowClosing = true;
Close();
Answered by Viachaslau Tysianchuk
Post is based on https://stackoverflow.com/questions/743906/how-to-hide-close-button-in-wpf-window