在xaml中作为事件处理程序的静态函数

Question

我使用这段代码来模拟我的silverlight应用程序中的选项卡功能。

我真的希望避免多次编写该函数，因为它必须在整个应用程序中用于相当多的文本框。我已经创建了一个静态类

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;
        }
    } 
}

这样我就可以从不同的地方访问它，比如这个textBox.KeyDown += TabInsert.textBox_KeyDown;

是否有一种方法可以在XAML中做到这一点?

Answer 1

您可以创建一个Behavior (System.Windows.)在OnAttached()覆盖中订阅事件，并像在OnDetaching()中做和取消订阅一样做处理的文本框。

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;
    }
}

Answer 2

不幸的是，在XAML中没有直接的方法来做到这一点。在后面代码中编写的事件处理程序必须是实例方法，而不能是静态方法。这些方法必须由由x: class标识的CLR名称空间中的部分类定义。您不能限定事件处理程序的名称，以指示XAML处理器在不同的类作用域中查找事件连接的事件处理程序。