Question

我有一个简单的应用程序（一个带有6个按钮的网格 - 两行3 - 用于测试），我正在处理左右箭头键，如下所示

    private void Window_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        FocusNavigationDirection focusDirection = new System.Windows.Input.FocusNavigationDirection();

        switch (e.Key)
        {
            case Key.Left:
                focusDirection = System.Windows.Input.FocusNavigationDirection.Left;
                break;
            case Key.Right:
                focusDirection = System.Windows.Input.FocusNavigationDirection.Right;
                break;
            default:
                break;
        }
        TraversalRequest request = new TraversalRequest(focusDirection);

        // Gets the element with keyboard focus.
        UIElement elementWithFocus = Keyboard.FocusedElement as UIElement;

        // Change keyboard focus.
        if (elementWithFocus != null)
        {
            elementWithFocus.MoveFocus(request);
        }

    }

不幸的是，这并不像我预期的那样，因为焦点似乎总是朝着与FocusNavigationDirection指定的方向相反的方向移动。

有关为何会这样做的任何想法？ MSDN Documentation对于如何定义“左边”有点模糊。

如果需要，我还将每个按钮的制表位定义为1到6。

Answer 1

为什么在使用“this”（窗口自己的范围）时需要获取elementWithFocus？

我修改了你的代码，这对我有用：

    private void Window_OnPreviewKeyDown(object sender, KeyEventArgs e)
    {
        switch (e.Key)
        {
            case Key.Left:
                this.MoveFocus(FocusNavigationDirection.Previous);
                break;
            case Key.Right:
                this.MoveFocus(FocusNavigationDirection.Next);
                break;
            default:
                break;
        }
    }

    private void MoveFocus(FocusNavigationDirection direction)
    {
        var request = new TraversalRequest(direction);
        this.MoveFocus(request);
    }

Answer 2

您是否尝试过FocusNavigationDirection.Previous（左侧）和FocusNavigationDirection.Next（右侧）？

这可能比其他值提供更可预测的行为。

WPF FocusNavigationDirection，MoveFocus和Arrow键

2 个答案: