ICommand 与 RoutedCommand [英] ICommand vs RoutedCommand
问题描述
让我们将按钮 Command 属性绑定到自定义命令.
Let's have a button Command property bound to a custom command.
我应该何时实施 ICommand 以及何时从 RoutedCommand 派生?我看到 RoutedCommand 实现了 ICommand.
When should I implement ICommand and when derive from RoutedCommand? I see that RoutedCommand implements ICommand.
在哪种情况下我需要实现 ICommand?MVVM模型呢?哪一个更适合这个目的?
In which case could I need to implement an ICommand?
What about MVVM model? Which one suits better for this purpose?
推荐答案
如您所见，RoutedCommand 类是ICommand接口的一个实现，主要区别在于它的功能类似于RoutedEvent:
As you have noticed the RoutedCommand class is an implementation of the ICommand interface, its main distinction if that its function is similar to that of a RoutedEvent:
RoutedCommand 上的 Execute 和 CanExecute 方法不像典型的 ICommand 那样包含命令的应用程序逻辑，相反，这些方法引发了遍历元素树以查找具有 CommandBinding 的对象的事件.附加到 CommandBinding 的事件处理程序包含命令逻辑.
The Execute and CanExecute methods on a RoutedCommand do not contain the application logic for the command as is the case with a typical ICommand, but rather, these methods raise events that traverse the element tree looking for an object with a CommandBinding. The event handlers attached to the CommandBinding contain the command logic.
Execute 方法引发 PreviewExecuted 和 Executed 事件.CanExecute 方法引发 PreviewCanExecute 和 CanExecute 事件.
The Execute method raises the PreviewExecuted and Executed events. The CanExecute method raises the PreviewCanExecute and CanExecute events.
如果您不想要 RoutedCommand 的行为，您将查看自己的 ICommand 实现.至于MVVM模式我不能说是一种解决方案，似乎每个人都有自己的方法论.但是，这里有一些我遇到的解决此问题的方法:
In a case when you don't want the behavior of the RoutedCommand you'll be looking at your own implementation of ICommand. As for the MVVM pattern I can't say that one solution, it seems that everyone has their own methodology. However, here are a few approaches to this problem that I've come across:
- 在 WPF 中使用带有 ViewModel 的 RoutedCommands
- 中继命令逻辑
- 简单命令(与 Relay Command 几乎相同但值得一读)
- Using RoutedCommands with a ViewModel in WPF
- Relaying Command Logic
- Simple Command (almost identical to Relay Command but worth reading)
这篇关于ICommand 与 RoutedCommand的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
