C# 自定义命令不工作

C# 自定义命令不工作,c#,.net,wpf,vb.net,xaml,C#,.net,Wpf,Vb.net,Xaml,在我的XAML中,我有: <UserControl.CommandBindings> <CommandBinding Command="Help" CanExecute="HelpCanExecute" Executed="HelpExecuted" /> </UserControl.CommandBindings> <MenuItem Header="Help" Command="Help" /> 并将我的XAML更改为:

在我的XAML中,我有:

<UserControl.CommandBindings>
    <CommandBinding Command="Help"
   CanExecute="HelpCanExecute"
   Executed="HelpExecuted" />
</UserControl.CommandBindings>

<MenuItem Header="Help" Command="Help" />
并将我的XAML更改为:

<UserControl.CommandBindings>
    <CommandBinding Command="MyCustomCommand"
   CanExecute="HelpCanExecute"
   Executed="HelpExecuted" />
</UserControl.CommandBindings>

<MenuItem Header="Help" Command="MyCustomCommand" />

但我得到了错误:无法将属性“Command”中的字符串“MyCustomCommand”转换为类型为“System.Windows.Input.ICommand”的对象。CommandConverter无法从System.String转换


我错过了什么?请注意,我想在XAML中完成这一切,也就是说,我不想使用CommandBindings.Add(new CommandBinding(MyCustomCommand…

对不起,发布我的原始答案有点快。我现在发现问题不在于类型,而在于CommandBinding。您需要使用标记扩展来解析命令名。我通常在命令声明中将命令设置为静态,如下所示:

namespace MyApp.Commands
{
    public class MyApplicationCommands
    {
        public static RoutedUICommand MyCustomCommand 
                               = new RoutedUICommand("My custom command", 
                                                     "MyCustomCommand", 
                                                     typeof(MyApplicationCommands));
    }
}
在XAML中:

<UserControl x:Class="..."
             ...
             xmlns:commands="clr-namespace:MyApp.Commands">
...
<UserControl.CommandBindings>
    <CommandBinding Command="{x:Static commands:MyApplicationCommands.MyCustomCommand}"
    CanExecute="HelpCanExecute"
    Executed="HelpExecuted" />
</UserControl.CommandBindings>

我更新了我的帖子,请看看这是否解决了您的问题。:-)XStatic是冗余的(至少从.Net 4开始),代码可能会更改为“Command=”commands:MyApplicationCommands.MyCustomCommand“,但我刚刚在中添加了x:Static,窗口中添加控件引用的错误消失了,控件现在呈现。(commandconverter无法从system.string、.net 4转换)
<UserControl x:Class="..."
             ...
             xmlns:commands="clr-namespace:MyApp.Commands">
...
<UserControl.CommandBindings>
    <CommandBinding Command="{x:Static commands:MyApplicationCommands.MyCustomCommand}"
    CanExecute="HelpCanExecute"
    Executed="HelpExecuted" />
</UserControl.CommandBindings>
public RoutedUICommand MyCustomCommand 
             = new RoutedUICommand("Description", "Name", typeof(ContainingClass));