The June CTP of .Net Framework 3.0 was released on Friday. One new June CTP feature that I am very excited to introduce is a new property on Window called AllowsTransparency. AllowsTransparency enables you to create those semi-transparent windows and rounded-corner windows for which many of you have been asking.
I have written a small sample to illustrate some of the things to think about when creating semi-transparent windows. The central part of the sample is the following XAML:
<Window x:Class="WindowTransparency.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="WindowTransparency" Height="300" Width="300"
AllowsTransparency="True" WindowStyle="None"
Background="Transparent"
>
<Border CornerRadius="50" Background="Blue" Opacity=".7">
<Button Click="CloseWindow" Height="30" Width="100">Close Me
</Button>
</Border>
</Window>
There are a few things to notice in this XAML. First is that I set Window.AllowsTransparency to true. Of course, as the name implies, this simply means that the Window may be made transparent (under the covers, it switches to using a layered window), it does not actually set the background to transparent. To achieve a transparent window, I set Window.Background to Transparent. Now that I have a transparent window surface, I can draw whatever content inside of it that I like. In this example, I’m simply using a Border with rounded corners to show that you can create rounded-corner windows and dialogs.
You’ll also notice that I have set Window.WindowStyle to None. For now, Windows with AllowsTransparency=true are not compatible with any of the other WindowStyles, and we expect that this will be fine for most scenarios (if you are using a transparent window, you probably don’t want the standard Win32 window chrome). Drawing your own Window chrome is easy (as an example, I’ve created a close button that I’ve hooked up to Window.Close()). Making your Window user-draggable is actually just as easy to do. The following code does it:
public Window1()
{
InitializeComponent();
MouseLeftButtonDown += new MouseButtonEventHandler
(Window1_MouseLeftButtonDown);
}
void Window1_MouseLeftButtonDown(object sender,
MouseButtonEventArgs e)
{
DragMove();
}
You can download the full sample here.
