[英]In WPF how do I implement ICommandSource to give my custom control ability to use Command from xaml?
能否请您提供一个示例,了解如何实现ICommandSource
接口。 因为我想要我的UserControl
,它不具备在xaml中指定命令的能力,以具备此功能。 并且能够在用户单击CustomControl
时处理该命令。
这是一个例子:
public partial class MyUserControl : UserControl, ICommandSource
{
public MyUserControl()
{
InitializeComponent();
}
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public static readonly DependencyProperty CommandProperty =
DependencyProperty.Register("Command", typeof(ICommand), typeof(MyUserControl), new UIPropertyMetadata(null));
public object CommandParameter
{
get { return (object)GetValue(CommandParameterProperty); }
set { SetValue(CommandParameterProperty, value); }
}
// Using a DependencyProperty as the backing store for CommandParameter. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CommandParameterProperty =
DependencyProperty.Register("CommandParameter", typeof(object), typeof(MyUserControl), new UIPropertyMetadata(null));
public IInputElement CommandTarget
{
get { return (IInputElement)GetValue(CommandTargetProperty); }
set { SetValue(CommandTargetProperty, value); }
}
// Using a DependencyProperty as the backing store for CommandTarget. This enables animation, styling, binding, etc...
public static readonly DependencyProperty CommandTargetProperty =
DependencyProperty.Register("CommandTarget", typeof(IInputElement), typeof(MyUserControl), new UIPropertyMetadata(null));
protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
{
base.OnMouseLeftButtonUp(e);
var command = Command;
var parameter = CommandParameter;
var target = CommandTarget;
var routedCmd = command as RoutedCommand;
if (routedCmd != null && routedCmd.CanExecute(parameter, target))
{
routedCmd.Execute(parameter, target);
}
else if (command != null && command.CanExecute(parameter))
{
command.Execute(parameter);
}
}
}
请注意, CommandTarget
属性仅用于RoutedCommands
您的UserControl将在文件cs或vb后面有一个代码,您必须实现接口ICommandSource,一旦实现它,在某些情况下您将必须实际调用该命令并检查CanExecute。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.