如何：在 StackPanel 和 DockPanel 之间进行选择

  • 项目

尽管可以使用或 DockPanel 或 StackPanel 堆叠子元素，但两个控件并不总是生成相同的结果。 例如，放置子元素的顺序可能会影响 DockPanel 中子元素的大小，但不会影响 StackPanel 中子元素的大小。 发生这种不同的行为是因为 StackPanel 在 Double.PositiveInfinity 的堆叠方向上测量；但是，DockPanel 仅测量可用大小。

本文中的示例创建包含两个面板的 Grid，如下图所示：

A grid with two panels and hearts.

XAML 示例

以下示例演示在 XAML 中设计页面时，DockPanel 和 StackPanel 之间的主要区别。

<Grid Width="175" Height="150">
    <Grid.Resources>
        <ControlTemplate x:Key="EmojiViewBox" TargetType="{x:Type ContentControl}">
            <Viewbox>
                <Border Background="LightGray" BorderBrush="Black" BorderThickness="0.5">
                    <TextBlock Foreground="Red">💕</TextBlock>
                </Border>
            </Viewbox>
        </ControlTemplate>
    </Grid.Resources>
    <Grid.RowDefinitions>
        <RowDefinition />
        <RowDefinition />
    </Grid.RowDefinitions>

    <DockPanel Grid.Column="0" Grid.Row="0">
        <ContentControl Template="{StaticResource EmojiViewBox}" />
        <ContentControl Template="{StaticResource EmojiViewBox}" />
        <ContentControl Template="{StaticResource EmojiViewBox}" />
    </DockPanel>

    <StackPanel Grid.Column="0" Grid.Row="1"  Orientation="Horizontal">
        <ContentControl Template="{StaticResource EmojiViewBox}" />
        <ContentControl Template="{StaticResource EmojiViewBox}" />
        <ContentControl Template="{StaticResource EmojiViewBox}" />
    </StackPanel>
</Grid>

基于代码的示例

以下示例演示了 DockPanel 和 StackPanel 之间的主要区别。 此代码在 Window.Loaded 事件处理程序中运行：

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    Grid gridContainer = new Grid()
    {
        Width = 175,
        Height = 150
    };

    // Template to generate the content
    ControlTemplate viewBoxTemplate = (ControlTemplate)System.Windows.Markup.XamlReader.Parse(@"
        <ControlTemplate TargetType=""ContentControl"" xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation"">
            <Viewbox>
                <Border Background=""LightGray"" BorderBrush=""Black"" BorderThickness=""0.5"">
                    <TextBlock Foreground=""Red"">💕</TextBlock>
                </Border>
            </Viewbox>
        </ControlTemplate>
        ");

    gridContainer.RowDefinitions.Add(new RowDefinition());
    gridContainer.RowDefinitions.Add(new RowDefinition());

    // Dock panel
    DockPanel panel1 = new DockPanel();
    Grid.SetRow(panel1, 0);

    // Create the three controls for the panel
    panel1.Children.Add(new ContentControl() { Template = viewBoxTemplate });
    panel1.Children.Add(new ContentControl() { Template = viewBoxTemplate });
    panel1.Children.Add(new ContentControl() { Template = viewBoxTemplate });

    // Add the dock panel to the grid
    gridContainer.Children.Add(panel1);

    // Stack panel
    StackPanel panel2 = new StackPanel();
    panel2.Orientation = Orientation.Horizontal;
    Grid.SetRow(panel2, 1);

    // Create the three controls for the panel
    panel2.Children.Add(new ContentControl() { Template = viewBoxTemplate });
    panel2.Children.Add(new ContentControl() { Template = viewBoxTemplate });
    panel2.Children.Add(new ContentControl() { Template = viewBoxTemplate });

    // Add the dock panel to the grid
    gridContainer.Children.Add(panel2);
    
    // Set the grid as the content of this window or page
    Content = gridContainer;
}

Private Sub Window_Loaded(sender As Object, e As RoutedEventArgs)
    Dim gridContainer As New Grid() With {.Width = 175, .Height = 150}

    ' Template to generate the content
    Dim viewBoxTemplate As ControlTemplate = DirectCast(Markup.XamlReader.Parse("
            <ControlTemplate TargetType=""ContentControl"" xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation"">
                <Viewbox>
                    <Border Background=""LightGray"" BorderBrush=""Black"" BorderThickness=""0.5"">
                        <TextBlock Foreground=""Red"">💕</TextBlock>
                    </Border>
                </Viewbox>
            </ControlTemplate>"), ControlTemplate)


    gridContainer.RowDefinitions.Add(New RowDefinition())
    gridContainer.RowDefinitions.Add(New RowDefinition())

    ' Dock panel
    Dim panel1 As New DockPanel()
    Grid.SetRow(panel1, 0)

    ' Create the three controls for the panel
    panel1.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})
    panel1.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})
    panel1.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})

    ' Add the dock panel to the grid
    gridContainer.Children.Add(panel1)

    ' Stack panel
    Dim panel2 As New StackPanel() With {.Orientation = Orientation.Horizontal}
    Grid.SetRow(panel2, 1)

    ' Create the three controls for the panel
    panel2.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})
    panel2.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})
    panel2.Children.Add(New ContentControl() With {.Template = viewBoxTemplate})

    ' Add the dock panel to the grid
    gridContainer.Children.Add(panel2)

    'Set the grid as the content of this window or page
    Content = gridContainer
End Sub

另请参阅