静态函数作为 xaml 中的事件处理程序

Question

我正在使用this 代码来模拟我的silverlight 应用程序中的选项卡功能。

我真的很想避免多次编写该函数，因为它必须在整个应用程序中的大量文本框中使用。我创建了一个静态类

public static class TabInsert
{
    private const string Tab = "    ";
    public static void textBox_KeyDown(object sender, KeyEventArgs e)
    {
        TextBox textBox = sender as TextBox;
        if (e.Key == Key.Tab)
        {
            int selectionStart = textBox.SelectionStart;
            textBox.Text = String.Format("{0}{1}{2}",
                    textBox.Text.Substring(0, textBox.SelectionStart),
                    Tab,
                    textBox.Text.Substring(textBox.SelectionStart + textBox.SelectionLength, (textBox.Text.Length) - (textBox.SelectionStart + textBox.SelectionLength))
                    );
            e.Handled = true;
            textBox.SelectionStart = selectionStart + Tab.Length;
        }
    } 
}

这样我就可以从各个地方访问它，就像textBox.KeyDown += TabInsert.textBox_KeyDown;

有没有办法在 XAML 中做到这一点？

Answer 1

很遗憾，there is no direct way to do this in XAML。你在后面代码中编写的事件处理程序必须是实例方法，不能是静态方法。这些方法必须由 x:Class 标识的 CLR 命名空间内的分部类定义。您不能限定事件处理程序的名称来指示 XAML 处理器在不同的类范围内查找事件处理程序以进行事件连接。

Answer 2

您可以创建一个行为（System.Windows.Interactivity 命名空间）以轻松附加到在 OnAttached() 覆盖中订阅事件的文本框，并像您一样进行处理并在 OnDetaching() 中取消订阅。

类似：

public class TabInsertBehavior : Behavior<TextBox>
{
    /// <summary>
    /// Called after the behavior is attached to an AssociatedObject.
    /// </summary>
    /// <remarks>
    /// Override this to hook up functionality to the AssociatedObject.
    /// </remarks>
    protected override void OnAttached()
    {
        base.OnAttached();
        this.AssociatedObject.KeyDown += textBox_KeyDown;
    }

    private const string Tab = "    ";
    public static void textBox_KeyDown(object sender, KeyEventArgs e)
    {
        TextBox textBox = sender as TextBox;
        if (e.Key == Key.Tab)
        {
            int selectionStart = textBox.SelectionStart;
            textBox.Text = String.Format("{0}{1}{2}",
                    textBox.Text.Substring(0, textBox.SelectionStart),
                    Tab,
                    textBox.Text.Substring(textBox.SelectionStart + textBox.SelectionLength, (textBox.Text.Length) - (textBox.SelectionStart + textBox.SelectionLength))
                    );
            e.Handled = true;
            textBox.SelectionStart = selectionStart + Tab.Length;
        }
    } 

    /// <summary>
    /// Called when the behavior is being detached from its AssociatedObject, but before it has actually occurred.
    /// </summary>
    /// <remarks>
    /// Override this to unhook functionality from the AssociatedObject.
    /// </remarks>
    protected override void OnDetaching()
    {
        base.OnDetaching();
        this.AssociatedObject.KeyDown -= textBox_KeyDown;
    }
}