【WPF】获取焦点全部选中事件

效果

功能

当TextBox获取焦点时，如TextBox中有内容，则默认全部选中

代码

public AddTaskWindow()
{
    InitializeComponent();
    //在文本框获取焦点时，要求其中内容全部选中
    txtContent.PreviewMouseDown += new MouseButtonEventHandler(txtContent_PreviewMouseDown);
    txtContent.GotFocus += new RoutedEventHandler(txtContent_GotFocus);
    txtContent.LostFocus += new RoutedEventHandler(txtContent_LostFocus);
}

/// <summary>
/// 番茄名称，获取焦点
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void txtContent_GotFocus(object sender, RoutedEventArgs e)
{
    txtContent.SelectAll();//全选
    txtContent.PreviewMouseDown -= new MouseButtonEventHandler(txtContent_PreviewMouseDown);   
}

/// 番茄名称，失去焦点
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void txtContent_LostFocus(object sender, RoutedEventArgs e)
{
    txtContent.PreviewMouseDown += new MouseButtonEventHandler(txtContent_PreviewMouseDown);
}

/// <summary>
/// 番茄名称，单击事件前
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void txtContent_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
    txtContent.Focus();
    e.Handled = true;
}