.net - 如何拦截编辑控件中的Tab键

Question

我需要 RichTextEdit 控件中 Tab 键的自定义行为。

目前我拥有的最好的是:

editBox.PreviewKeyDown += new System.Windows.Forms.PreviewKeyDownEventHandler(this.field_PreviewKeyPress);


  private void field_PreviewKeyPress(object sender, PreviewKeyDownEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.Tab: 
                     //Some code here
                break;
            }
        }

Tab 键注册正常，但之后控件无论如何都会处理该键并将焦点移动到下一个控件。似乎没有办法消耗这个关键事件。

Answer 1

也许这篇 CodeProject 文章可以给您一些提示:

TabKeyIntercept - Intercept and process the Tab key in a Windows.Forms form

[...] Fortunately, in the base Form class, there exists the protected override bool ProcessTabKey(bool forward) method. Using this method, we can intercept and "consume" the Tab key.

And, as it turns out, if the ProcessTabKey() method's return value is false, the Tab key does make it into the OnKeyDown() method. But, of course, if your code "consumes" the Tab key in the ProcessTabKey() method, you probably won't need to process it in the OnKeyDown() method.

Also, the Control-Tab combination makes it into the OnKeyDown() method.

So, knowing these things, we are prepared to define a customized use for the Tab key -- and we can code the form to allow the user to use the Control-Tab combination to toggle between the normal use/meaning of the Tab key and our custom use.