这个简单的实现非常适合我:

void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
    ((TextBox) sender).SelectAll();
}

void TextBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    var TextBox = (TextBox) sender;
    if (!TextBox.IsKeyboardFocusWithin)
    {
        TextBox.Focus();
        e.Handled = true;
    }
}

把它应用到所有的文本框，把下面的代码InitializeComponent();

EventManager.RegisterClassHandler(typeof(TextBox), TextBox.GotFocusEvent, new RoutedEventHandler(TextBox_GotFocus));
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.PreviewMouseDownEvent, new MouseButtonEventHandler(TextBox_PreviewMouseDown));

一个简单的方法来覆盖鼠标向下和选择所有双击后:

public class DoubleClickTextBox: TextBox
{

    public override void EndInit()
    {
        base.EndInit();            
    }

    protected override void OnMouseEnter(System.Windows.Input.MouseEventArgs e)
    {
        base.OnMouseEnter(e);
        this.Cursor = Cursors.Arrow;
    }
    protected override void OnMouseDown(System.Windows.Input.MouseButtonEventArgs e)
    {

    }

    protected override void OnMouseDoubleClick(System.Windows.Input.MouseButtonEventArgs e)
    {
        base.OnMouseDown(e);
        this.SelectAll();
    }
}

#region TextBoxIDCard selection
private bool textBoxIDCardGotFocus = false;
private void TextBoxIDCard_GotFocus(object sender, RoutedEventArgs e)
{
    this.TextBoxIDCard.SelectAll();
}

private void TextBoxIDCard_LostFocus(object sender, RoutedEventArgs e)
{
    textBoxIDCardGotFocus = false;
}

private void TextBoxIDCard_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    if (textBoxIDCardGotFocus == false)
    {
        e.Handled = true;
        this.TextBoxIDCard.Focus();
        textBoxIDCardGotFocus = true;
    }
} 
#endregion

我知道这是非常古老的，但这是我的解决方案，它是基于表达式/微软交互性和交互名称空间。

首先，我按照此链接中的说明将交互性触发器放入样式中。

然后就归结为这个

<Style x:Key="baseTextBox" TargetType="TextBox">
  <Setter Property="gint:InteractivityItems.Template">
    <Setter.Value>
      <gint:InteractivityTemplate>
        <gint:InteractivityItems>
          <gint:InteractivityItems.Triggers>
            <i:EventTrigger EventName="GotKeyboardFocus">
              <ei:CallMethodAction MethodName="SelectAll"/>
            </i:EventTrigger>
            <i:EventTrigger EventName="PreviewMouseLeftButtonDown">
              <ei:CallMethodAction MethodName="TextBox_PreviewMouseLeftButtonDown"
                TargetObject="{Binding ElementName=HostElementName}"/>
            </i:EventTrigger>
          </gint:InteractivityItems.Triggers>
        </gint:InteractivityItems>
      </gint:InteractivityTemplate>
    </Setter.Value>
  </Setter>
</Style>

这

public void TextBox_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
  TextBox tb = e.Source as TextBox;
  if((tb != null) && (tb.IsKeyboardFocusWithin == false))
  {
    tb.Focus();
    e.Handled = true;
  }
}

在我的例子中，我有一个用户控件，其中的文本框有一个隐藏代码。隐藏代码具有处理程序函数。我在XAML中为用户控件设置了一个名称，并将该名称用于元素。这对我来说非常有效。简单地应用样式的任何文本框，你想有所有的文本选择时，点击在文本框。

当TextBox上的GotKeyboardFocus事件触发时，第一个CallMethodAction调用文本框的SelectAll方法。

我希望这能有所帮助。

在App.xaml文件中:

<Application.Resources>
    <Style TargetType="TextBox">
        <EventSetter Event="GotKeyboardFocus" Handler="TextBox_GotKeyboardFocus"/>
    </Style>
</Application.Resources>

在App.xaml.cs文件中:

private void TextBox_GotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
{
    ((TextBox)sender).SelectAll();
}

有了这段代码，你可以在你的应用程序中找到所有的文本框。

这似乎对我有用……

private bool TextBoxFocusBool;

private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
    TextBoxFocusBool = true;
}

private void TextBox_LostMouseCapture(object sender, MouseEventArgs e)
{
    if (TextBox.SelectionLength == 0 & TextBoxFocusBool == true)
    {
        TextBox.SelectAll();
        TextBoxFocusBool = false;
    }
}

private void TextBox_LostFocus(object sender, RoutedEventArgs e)
{
    TextBoxFocusBool = true;
}