I am trying to create a borderless window in WPF. I am using the class mentioned in the link.
This works fine as long as all elements are all enabled (Opacity = 1). if i set opacity to 0.5, it is almost invisible.
The opacity works fine if i remove the code for the drop shadow. I am not sure what is the cause of this.
The class is the same one i am using as explained in link above. The rest of my code is below.
Any help is appreciated :
- Girija
XAML:
<Window x:Class="Sample.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Sample">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="70"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<TextBox Margin="2" Text="Something" Grid.Row="0"/>
<Button Grid.Row="1" Content="Something" IsEnabled="False" Opacity="0.7"/>
</Grid>
Code behind :
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
/// <summary>
/// Raises the <see cref="E:System.Windows.FrameworkElement.Initialized"/> event.
/// This method is invoked whenever
/// <see cref="P:System.Windows.FrameworkElement.IsInitialized"/> is set to true internally.
/// </summary>
/// <param name="e">The <see cref="T:System.Windows.RoutedEventArgs"/>
/// that contains the event data.</param>
protected override void OnInitialized(EventArgs e)
{
//AllowsTransparency = false;
ResizeMode = ResizeMode.NoResize;
WindowStartupLocation = WindowStartupLocation.CenterScreen;
WindowStyle = WindowStyle.None;
DwmDropShadow.DropShadowToWindow(this);
base.OnInitialized(e);
}
}
helper Class taken from above link :
class DwmDropShadow
{
[DllImport("dwmapi.dll", PreserveSig = true)]
private static extern int DwmSetWindowAttribute(IntPtr hwnd, int attr, ref int attrValue, int attrSize);
[DllImport("dwmapi.dll")]
private static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref Margins pMarInset);
/// <summary>
/// Drops a standard shadow to a WPF Window, even if the window isborderless. Only works with DWM (Vista and Seven).
/// This method is much more efficient than setting AllowsTransparency to true and using the DropShadow effect,
/// as AllowsTransparency involves a huge permormance issue (hardware acceleration is turned off for all the window).
/// </summary>
/// <param name="window">Window to which the shadow will be applied</param>
public static void DropShadowToWindow(Window window)
{
if (!DropShadow(window))
{
window.SourceInitialized += new EventHandler(window_SourceInitialized);
}
}
private static void window_SourceInitialized(object sender, EventArgs e)
{
Window window = (Window)sender;
DropShadow(window);
window.SourceInitialized -= new EventHandler(window_SourceInitialized);
}
/// <summary>
/// The actual method that makes API calls to drop the shadow to the window
/// </summary>
/// <param name="window">Window to which the shadow will be applied</param>
/// <returns>True if the method succeeded, false if not</returns>
private static bool DropShadow(Window window)
{
try
{
WindowInteropHelper helper = new WindowInteropHelper(window);
int val = 2;
int ret1 = DwmSetWindowAttribute(helper.Handle, 2, ref val, 4);
if (ret1 == 0)
{
Margins m = new Margins { Bottom = 0, Left = 0, Right = 0, Top = 0 };
int ret2 = DwmExtendFrameIntoClientArea(helper.Handle, ref m);
return ret2 == 0;
}
else
{
return false;
}
}
catch (Exception ex)
{
// Probably dwmapi.dll not found (incompatible OS)
return false;
}
}
}
