为什么 UserControl 没有填充 VerticalContentAlignment 'Stretch'？

Question

这是父级 Xaml:

<Grid VerticalAlignment="Stretch">
    <Grid.RowDefinitions>
        <RowDefinition Height="20" />
        <RowDefinition Height="*" /><!-- Should stretch vertically -->
    </Grid.RowDefinitions>
    <DockPanel Grid.Row="0">
        <!-- Menu definition removed for brevity -->
    </DockPanel>
    <DockPanel Grid.Row="1"
               VerticalAlignment="Stretch"
               LastChildFill="True">
        <ItemsControl DockPanel.Dock="Top"
                      ItemsSource="{Binding Designer}"
                      HorizontalAlignment="Stretch"
                      HorizontalContentAlignment="Stretch"
                      VerticalAlignment="Stretch"
                      VerticalContentAlignment="Stretch"
                      Background="YellowGreen"/>
    </DockPanel>
</Grid>

ItemsSource 绑定到 ObservableCollection。当视图添加到集合中时，它会在主shell（视图）中更新。这是添加的 UserControl：

<UserControl x:Class="Prototype.StateMachineDesignerApp.Views.ProjectDesigner"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:local="clr-namespace:Prototype.StateMachineDesignerApp.Views"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="500"
             HorizontalAlignment="Stretch"
             HorizontalContentAlignment="Stretch"
             VerticalAlignment="Stretch"
             VerticalContentAlignment="Stretch"
             Margin="0">
    <Grid VerticalAlignment="Stretch">
        <Grid.RowDefinitions>
            <RowDefinition Height="20" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Border Grid.Row="0"
                BorderBrush="DimGray"
                BorderThickness="1"
                Background="LightSlateGray"
                Margin="1" />
        <Border Grid.Row="1"
                Margin="1">
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="1*" />
                    <ColumnDefinition Width="3" />
                    <ColumnDefinition Width="5*" />
                </Grid.ColumnDefinitions>
                <Border Grid.Column="0"
                        BorderBrush="DarkGoldenrod"
                        BorderThickness="1" />
                <GridSplitter Grid.Column="1"
                              HorizontalAlignment="Stretch"
                              VerticalAlignment="Stretch" />
                <Border Grid.Column="2"
                        BorderBrush="DarkGoldenrod"
                        BorderThickness="1" />
            </Grid>
        </Border>
    </Grid>
</UserControl>

UserControl 没有填满整个垂直 space：

最外层 Grid 的

Row[1] 正在垂直拉伸，ItemsControl.Background 填充该区域就是证明。

供参考，这是我所期待的：

关于它的价值，我已经在 SO 上查看了许多关于这个确切问题的问题，但 none 的解决方案似乎有所帮助。再一次，我看到的 none 个示例使用了 ItemsControl 和绑定。

Answer 1

发生这种情况是因为 ItemsControl 默认情况下将我们所有的项目放入垂直对齐的 StackPanel 中。不过更改起来非常容易，因为 ItemsControl 允许您更改用于容纳所有项目的面板类型。

<ItemsControl DockPanel.Dock="Top"
                  ItemsSource="{Binding Designer}"
                  HorizontalAlignment="Stretch"
                  HorizontalContentAlignment="Stretch"
                  VerticalAlignment="Stretch"
                  VerticalContentAlignment="Stretch"
                  Background="Transparent">
  <ItemsControl.ItemsPanel>
    <ItemsPanelTemplate>
         <Grid />
    </ItemsPanelTemplate>
 </ItemsControl.ItemsPanel>
</ItemsControl>

为什么 UserControl 没有填充 VerticalContentAlignment 'Stretch'？

Why UserControl isn't filling VerticalContentAlignment 'Stretch'?

c#

wpf

xaml

user-controls