调试的CommandBinding的CanExecute [英] Debugging CommandBinding's CanExecute

问题描述

我有一个按钮绑定到 NavigationCommands.RefreshCommand 用户控件。该处理程序命令在父控件。该处理程序的 CanExecute 是这样的：

I have a user control with a Button bound to the NavigationCommands.RefreshCommand. The handler for the command is in the parent control. The handler's CanExecute looks like this:

e.CanExecute = !IsConnecting; // IsConnecting is a Dependency Property

由于某些原因，在按钮将保持禁用，直到我点击窗口。

For some reason, the Button will remain disabled until I click on the window.

如果我点击按钮，并得到它来执行（这会导致 IsConnecting 来临时设置为true）那么它会正确地关闭按钮，但不会启用按钮，直到我造成另一个事件窗口（如点击）。

If I click the Button and get it to execute (which causes IsConnecting to temporarily be set to true) it will then disable the button correctly, but won't enable the button until I cause another event in the window (eg. a click).

是否有任何工具或技巧，我可以用它来尝试调试它绑定到一个按钮命令的CanExecute处理？

推荐答案

当事情发生在GUI按钮的CanExecute只调用。由于IsConnecting改变在后台然后WPF不更新控制

The button's CanExecute is only called when something happens in the GUI. Since the IsConnecting changes in the background then WPF doesn't update the control.

要强制WPF更新CanExecute呼叫<一href="http://msdn.microsoft.com/en-us/library/system.windows.input.commandmanager.invalidaterequerysuggested.aspx"相对=nofollow> CommandManager.InvalidateRequerySuggested

To force WPF to update the CanExecute call CommandManager.InvalidateRequerySuggested

这篇关于调试的CommandBinding的CanExecute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！