一、使用Attached Dependency Property的方式
（1）定义Attached Dependency Property
public static class DigitsOnlyBehavior
{
public static bool GetIsDigitOnly(DependencyObject obj)
{
return (bool)obj.GetValue(IsDigitOnlyProperty);
} public static void SetIsDigitOnly(DependencyObject obj, bool value)
{
obj.SetValue(IsDigitOnlyProperty, value);
} public static readonly DependencyProperty IsDigitOnlyProperty =
DependencyProperty.RegisterAttached("IsDigitOnly",
typeof(bool), typeof(DigitsOnlyBehavior),
new PropertyMetadata(false, OnIsDigitOnlyChanged)); private static void OnIsDigitOnlyChanged(object sender, DependencyPropertyChangedEventArgs e)
{
// ignoring error checking
var textBox = (TextBox)sender;
var isDigitOnly = (bool)(e.NewValue); if (isDigitOnly)
textBox.PreviewTextInput += BlockNonDigitCharacters;
else
textBox.PreviewTextInput -= BlockNonDigitCharacters;
} private static void BlockNonDigitCharacters(object sender, TextCompositionEventArgs e)
{
e.Handled = e.Text.Any(ch => !Char.IsDigit(ch));
}
}
使用上面定义好的Attached Dependency Property
<TextBox Grid.Row="0" behaviors:DigitsOnlyBehavior.IsDigitOnly="True" Margin="6"/>
二、使用Behavior<T>
（1） 定义Behavior
public class DragBehavior : Behavior<UIElement>
{
private Point elementStartPosition;
private Point mouseStartPosition;
private TranslateTransform transform = new TranslateTransform(); protected override void OnAttached()
{
Window parent = Application.Current.MainWindow;
AssociatedObject.RenderTransform = transform; AssociatedObject.MouseLeftButtonDown += (sender, e) =>
{
elementStartPosition = AssociatedObject.TranslatePoint( new Point(), parent );
mouseStartPosition = e.GetPosition(parent);
AssociatedObject.CaptureMouse();
}; AssociatedObject.MouseLeftButtonUp += (sender, e) =>
{
AssociatedObject.ReleaseMouseCapture();
}; AssociatedObject.MouseMove += (sender, e) =>
{
Vector diff = e.GetPosition( parent ) - mouseStartPosition;
if (AssociatedObject.IsMouseCaptured)
{
transform.X = diff.X;
transform.Y = diff.Y;
}
};
}
}
（2）使用Behavior
<Border Background="LightBlue" >
<e:Interaction.Behaviors>
<b:DragBehavior/>
</e:Interaction.Behaviors>
<TextBlock Text="Drag me around!" />
</Border>