如何影响 WPF 中的键盘焦点遍历策略？

Question

假设有两个 WPF 列表。我希望能够使用键盘箭头键无缝地遍历它列出的项目。默认情况下，焦点范围仅限于单个容器内的迭代。有什么办法可以帮助它跨越集装箱边界吗？

Answer 1

假设有两个ListViews:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition/>
        <RowDefinition/>
    </Grid.RowDefinitions>
    <ListView x:Name="list1" KeyDown="list1_KeyDown">
        <ListViewItem Content="item 1"/>
        <ListViewItem Content="item 2"/>
        <ListViewItem Content="item 3"/>
    </ListView>
    <ListView x:Name="list2" Grid.Row="1" KeyDown="list2_KeyDown">
        <ListViewItem Content="item 1"/>
        <ListViewItem Content="item 2"/>
        <ListViewItem Content="item 3"/>
    </ListView>
</Grid>

为 KeyDown 事件添加两个处理程序：

private void list1_KeyDown(object sender, KeyEventArgs e) {
    switch (e.Key) {
        // check for down key
        case Key.Down:
            // if the bottom item is selected
            if (list1.SelectedIndex == list1.Items.Count - 1) {
                // select the next item
                list2.SelectedIndex = 0;
                (list2.Items[0] as UIElement).Focus();
                // make sure nothing else happens
                e.Handled = true;
            }
            break;
    }
}

private void list2_KeyDown(object sender, KeyEventArgs e) {
    switch (e.Key) {
        // check for up key
        case Key.Up:
            // if the top item is selected
            if (list2.SelectedIndex == 0) {
                // select the previous item
                int i = list1.Items.Count - 1;
                list1.SelectedIndex = i;
                (list1.Items[i] as UIElement).Focus();
                // make sure nothing else happens
                e.Handled = true;
            }
            break;
    }
}

这将允许使用 up/down 键在两个 ListView 之间进行无缝垂直过渡。您可以添加更多案例块以添加额外的 left/right 转换或其他内容。我相信您可以想出如何使它适应您的具体情况。

Answer 2

刚刚弄明白了。 KeyboardNavigation.DirectionalNavigation attached property does the trick. (possible values listed here)

示例可以简化为：

<StackPanel KeyboardNavigation.DirectionalNavigation="Contained">
  <ListBox KeyboardNavigation.DirectionalNavigation="Continue">
    <ListBoxItem Content="Item 1" />
    <ListBoxItem Content="Item 2" />
    <ListBoxItem Content="Item 3" />
  </ListBox>
  <ListBox KeyboardNavigation.DirectionalNavigation="Continue">
    <ListBoxItem Content="Item A" />
    <ListBoxItem Content="Item B" />
    <ListBoxItem Content="Item C" />
  </ListBox>
</StackPanel>

如何影响 WPF 中的键盘焦点遍历策略？

How to influence keyboard focus traversal policy in WPF?

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