在DataGrid中，我在行标题中添加了一个Expander，它在功能上运行良好，但是在展开时它会垂直居中。
我希望它保留在首页点击标题的顶部。
我在这里缺少什么？
<DataGrid Name="dgAudit"
CanUserReorderColumns="False"
CanUserAddRows="False"
CanUserDeleteRows="False"
CanUserResizeColumns="False"
CanUserResizeRows="False"
CanUserSortColumns="False"
IsReadOnly="True"
ItemsSource="{Binding GEOM_ASSET_OC_LIST}"
HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto"
AutoGenerateColumns="False"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
RowDetailsVisibilityMode="Collapsed"
>
<DataGrid.RowHeaderTemplate>
<DataTemplate>
<Expander Template="{StaticResource NewExpander}"
OverridesDefaultStyle="True"
Header=""
HorizontalAlignment="Right"
VerticalAlignment="Top"
Expanded="Expander_Expanded" Collapsed="Expander_Collapsed"
>
</Expander>
</DataTemplate>
</DataGrid.RowHeaderTemplate>
<DataGrid.Columns>...
这是主要模板：
<ControlTemplate x:Key="NewExpander" TargetType="{x:Type Expander}">
<DockPanel>
<ToggleButton x:Name="ExpanderButton"
DockPanel.Dock="Top"
Template="{StaticResource AnimatedExpanderButtonTemp}"
Content="{TemplateBinding Header}"
IsChecked="{Binding Path=IsExpanded, RelativeSource={RelativeSource TemplatedParent}}"
OverridesDefaultStyle="True"
Padding="0.5,0">
</ToggleButton>
</DockPanel>
</ControlTemplate>
以下是动画的模板：
<ControlTemplate x:Key="AnimatedExpanderButtonTemp" TargetType="{x:Type ToggleButton}">
<Border x:Name="ExpanderButtonBorder"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}" >
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Rectangle Fill="Transparent"
Grid.ColumnSpan="2"/>
<Ellipse Name="Circle"
Grid.Column="0"
Stroke="DarkGray"
Fill="LightGray"
Width="15"
Height="15"
HorizontalAlignment="Center"
VerticalAlignment="Center" />
<Path x:Name="Arrow"
Grid.Column="0"
Data="M 1,1.5 L 4.5,5 8,1.5"
Stroke="#FF666666"
StrokeThickness="2"
HorizontalAlignment="Center"
VerticalAlignment="Center"
RenderTransformOrigin="0.5,0.5" >
<Path.RenderTransform>
<RotateTransform Angle="0"/>
</Path.RenderTransform>
</Path>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked"
Value="True">
<Trigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Arrow"
Storyboard.TargetProperty="(Path.RenderTransform).(RotateTransform.Angle)"
To="180"
Duration="0:0:0.4"/>
</Storyboard>
</BeginStoryboard>
</Trigger.EnterActions>
<Trigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<DoubleAnimation Storyboard.TargetName="Arrow"
Storyboard.TargetProperty="(Path.RenderTransform).(RotateTransform.Angle)"
To="0"
Duration="0:0:0.4"/>
</Storyboard>
</BeginStoryboard>
</Trigger.ExitActions>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Stroke" Value="#FF3C7FB1" TargetName="Circle"/>
<Setter Property="Stroke" Value="#222" TargetName="Arrow"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Stroke" Value="#FF526C7B" TargetName="Circle"/>
<Setter Property="StrokeThickness" Value="1.5" TargetName="Circle"/>
<Setter Property="Stroke" Value="#FF003366" TargetName="Arrow"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
以下是展开崩溃事件：
private void Expander_Expanded(object sender, RoutedEventArgs e)
{
for (var vis = sender as Visual; vis != null; vis = VisualTreeHelper.GetParent(vis) as Visual)
if (vis is DataGridRow)
{
var row = (DataGridRow)vis;
row.DetailsVisibility = row.DetailsVisibility == Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
break;
}
}
private void Expander_Collapsed(object sender, RoutedEventArgs e)
{
for (var vis = sender as Visual; vis != null; vis = VisualTreeHelper.GetParent(vis) as Visual)
if (vis is DataGridRow)
{
var row = (DataGridRow)vis;
row.DetailsVisibility = row.DetailsVisibility == Visibility.Visible ? Visibility.Collapsed : Visibility.Visible;
break;
}
}
答案 0 :(得分：0)
默认ContentPresenter模板中的DataGridRowHeader具有VericalAlignment Center的硬编码。您需要修改模板才能解决此问题：
<DataGrid.Resources>
<BooleanToVisibilityConverter x:Key="bool2VisibilityConverter"/>
<Style x:Key="RowHeaderGripperStyle" TargetType="{x:Type Thumb}">
<Setter Property="Height" Value="8"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Cursor" Value="SizeNS"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Thumb}">
<Border Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type DataGridRowHeader}"
xmlns:Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero2">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DataGridRowHeader}">
<Grid>
<Themes:DataGridHeaderBorder BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" IsPressed="{TemplateBinding IsPressed}" IsHovered="{TemplateBinding IsMouseOver}" IsSelected="{TemplateBinding IsRowSelected}" Orientation="Horizontal" Padding="{TemplateBinding Padding}" SeparatorBrush="{TemplateBinding SeparatorBrush}" SeparatorVisibility="{TemplateBinding SeparatorVisibility}">
<StackPanel Orientation="Horizontal">
<ContentPresenter RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="Stretch"/>
<Control SnapsToDevicePixels="false" Template="{Binding ValidationErrorTemplate, RelativeSource={RelativeSource AncestorType={x:Type DataGridRow}}}" Visibility="{Binding (Validation.HasError), Converter={StaticResource bool2VisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGridRow}}}"/>
</StackPanel>
</Themes:DataGridHeaderBorder>
<Thumb x:Name="PART_TopHeaderGripper" Style="{StaticResource RowHeaderGripperStyle}" VerticalAlignment="Top"/>
<Thumb x:Name="PART_BottomHeaderGripper" Style="{StaticResource RowHeaderGripperStyle}" VerticalAlignment="Bottom"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</DataGrid.Resources>
不要忘记添加对PresentationFramework.Aero2.dll的引用。