如何在 WPF TextBox 中自动选择焦点上的所有文本? [英] How to automatically select all text on focus in WPF TextBox?

问题描述

如果我从 GotFocus 事件处理程序中调用 SelectAll，它对鼠标不起作用 - 一旦释放鼠标，选择就会消失.

If I call SelectAll from a GotFocus event handler, it doesn't work with the mouse - the selection disappears as soon as mouse is released.

人们喜欢 Donnelle 的回答，我将尝试解释为什么我不像接受的答案那样喜欢它.

People are liking Donnelle's answer, I'll try to explain why I did not like it as much as the accepted answer.

• 它更复杂，而接受的答案以更简单的方式做同样的事情.
• 接受答案的可用性更好.当您单击文本中间时，当您松开鼠标时，文本将被取消选择，允许您立即开始编辑，如果您仍想全选，只需再次按下按钮，这次它不会在松开时取消选择.按照 Donelle 的食谱，如果我单击文本中间，则必须第二次单击才能进行编辑.如果我点击文本内的某处而不是文本外的某处，这很可能意味着我想开始编辑而不是覆盖所有内容.

推荐答案

不知道为什么它在 GotFocus 事件中丢失了选择.

Don't know why it loses the selection in the GotFocus event.

但一种解决方案是对 GotKeyboardFocus 和 GotMouseCapture 事件进行选择.这样它就会一直有效.

But one solution is to do the selection on the GotKeyboardFocus and the GotMouseCapture events. That way it will always work.

-- 编辑 --

在此处添加一个示例，向人们展示如何解决提到的一些缺点:

Adding an example here to show people how to work around some the mentioned drawbacks:

private void TextBox_GotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
    // Fixes issue when clicking cut/copy/paste in context menu
    if (textBox.SelectionLength == 0) 
        textBox.SelectAll();
}

private void TextBox_LostMouseCapture(object sender, MouseEventArgs e)
{
    // If user highlights some text, don't override it
    if (textBox.SelectionLength == 0) 
        textBox.SelectAll();

    // further clicks will not select all
    textBox.LostMouseCapture -= TextBox_LostMouseCapture; 
}

private void TextBox_LostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
    // once we've left the TextBox, return the select all behavior
    textBox.LostMouseCapture += TextBox_LostMouseCapture;
}

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