C# 如何制作 WPF Expander Stretch？
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How can I make a WPF Expander Stretch?
提问by nmdr
The Expandercontrol in WPF does not stretch to fill all the available space. Is there any solutions in XAML for this?
ExpanderWPF 中的控件不会拉伸以填充所有可用空间。XAML 中有任何解决方案吗？
采纳答案by Jonathan Parker
All you need to do is this:
您需要做的就是：
<Expander>
<Expander.Header>
<TextBlock
Text="I am header text..."
Background="Blue"
Width="{Binding
RelativeSource={RelativeSource
Mode=FindAncestor,
AncestorType={x:Type Expander}},
Path=ActualWidth}"
/>
</Expander.Header>
<TextBlock Background="Red">
I am some content...
</TextBlock>
</Expander>
http://joshsmithonwpf.wordpress.com/2007/02/24/stretching-content-in-an-expander-header/
http://joshsmithonwpf.wordpress.com/2007/02/24/stretching-content-in-an-expander-header/
回答by Arcturus
Non stretchable Expanders is usually the problem of non stretchable parent controls.. Perhaps one of the parent controls has defined a HorizontalAlignmentor VerticalAlignmentproperty?
不可拉伸的Expanders通常是不可拉伸的父控件的问题。也许其中一个父控件定义了一个HorizontalAlignment或VerticalAlignment属性？
If you can post some sample code, we can give you a better answer.
如果您可以发布一些示例代码，我们可以为您提供更好的答案。
回答by Mark
I Agree with HTH - check what sort of a container you're putting the Expander in... the StackPanel will always fold it's children down to the smallest size they can go to.
我同意 HTH - 检查您将扩展器放入哪种容器中...... StackPanel 将始终将其子项折叠到他们可以达到的最小尺寸。
I'm using Expanders a lot in my project, and if you drop them into a Grid / DockPanel, then the expander will fill all available space (assuming it's Vertical & Horizontal orientations are set to Stretch).
我在我的项目中经常使用扩展器，如果你将它们放入网格/DockPanel，那么扩展器将填充所有可用空间（假设它的垂直和水平方向设置为拉伸）。
Jonathan's suggestion of Binding the Expander's width to the container's width can get a bit tricky... I tried this technique a few weeks back and found that it can producte undesirable results in some cases, because it can inhibit the functioning of the layout system.
乔纳森关于将扩展器的宽度绑定到容器的宽度的建议可能有点棘手......几周前我尝试过这种技术，发现它在某些情况下会产生不良结果，因为它会抑制布局系统的功能。
PS: As a general tip (and I'm sure I'm gonna get flamed for writing this), if you're unsure of what sort of layout-container to your controls in, then start off with a Grid. Using the Column & Row definitions allows you to very easily control whether child controls use minimum space ("Auto"), maximum space ("*") or an exact amount of space ("[number]").
PS：作为一般提示（我敢肯定我会因为写这篇文章而被激怒），如果您不确定控件的布局容器类型，那么从网格开始。使用列和行定义可以非常轻松地控制子控件是使用最小空间（“自动”）、最大空间（“*”）还是精确的空间量（“[数字]”）。
回答by Anthony Brien
The Silverlight Toolkit includes an Accordioncontrol which acts like an expander that always stretches to the available space. I haven't tested it yet, but it might be functional for WPF too, like the Silverlight Chart controls.
Silverlight Toolkit 包括一个Accordion控件，它的作用就像一个始终延伸到可用空间的扩展器。我还没有测试过它，但它可能也适用于 WPF，就像 Silverlight Chart 控件一样。
回答by Mark Smith
This solution is a lot simpler and does not effect other expander controls you may using in your application.
此解决方案要简单得多，并且不会影响您可能在应用程序中使用的其他扩展器控件。
<Expander ExpandDirection="Right" Grid.Column="0" Name="topOfB">
<Expander.Header>
<Grid HorizontalAlignment="Stretch" Width="{Binding Path=ActualWidth, ElementName=topOfB}">
<!-- control content goes here -->
回答by Amer Sawan
<Expander Name="EXPANDER_NAME">
<Expander IsExpanded="True" Margin="0">
<Expander.Header>
<Grid Background="Red" Width="{Binding ElementName=EXPANDER_NAME, Path=ActualWidth}">
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition Width="30"/>
</Grid.ColumnDefinitions>
<TextBlock> HEADER TEXT <TextBlock>
</Grid>
</Expander.Header>
</Expander>
回答by Johan Larsson
The accepted answer draws outside the control because the header content is in one column and the expander button is in the first. Might be good enough for some cases.
接受的答案在控件之外绘制，因为标题内容位于一列中，而扩展器按钮位于第一列中。对于某些情况可能已经足够了。
If you want a clean solution you have to change the template of the expander.
如果您想要一个干净的解决方案，您必须更改扩展器的模板。
Another way is an attached property:
另一种方式是附加属性：
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
public static class ParentContentPresenter
{
public static readonly System.Windows.DependencyProperty HorizontalAlignmentProperty = System.Windows.DependencyProperty.RegisterAttached(
"HorizontalAlignment",
typeof(HorizontalAlignment),
typeof(ParentContentPresenter),
new PropertyMetadata(default(HorizontalAlignment), OnHorizontalAlignmentChanged));
public static void SetHorizontalAlignment(this UIElement element, HorizontalAlignment value)
{
element.SetValue(HorizontalAlignmentProperty, value);
}
[AttachedPropertyBrowsableForChildren(IncludeDescendants = false)]
[AttachedPropertyBrowsableForType(typeof(UIElement))]
public static HorizontalAlignment GetHorizontalAlignment(this UIElement element)
{
return (HorizontalAlignment)element.GetValue(HorizontalAlignmentProperty);
}
private static void OnHorizontalAlignmentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var presenter = d.Parents().OfType<ContentPresenter>().FirstOrDefault();
if (presenter != null)
{
presenter.HorizontalAlignment = (HorizontalAlignment) e.NewValue;
}
}
private static IEnumerable<DependencyObject> Parents(this DependencyObject child)
{
var parent = VisualTreeHelper.GetParent(child);
while (parent != null)
{
yield return parent;
child = parent;
parent = VisualTreeHelper.GetParent(child);
}
}
}
It lets you do:
它可以让你：
<Expander Header="{Binding ...}">
<Expander.HeaderTemplate>
<DataTemplate>
<!--Using a border here to show how width changes-->
<Border BorderBrush="Red" BorderThickness="1"
local:ParentContentPresenter.HorizontalAlignment="Stretch">
...
</Border>
</DataTemplate>
</Expander.HeaderTemplate>
</Expander>
Note that the use of the attached property is somewhat fragile as it assumes that there is a ContentPresenterin the template.
请注意，附加属性的使用有点脆弱，因为它假定ContentPresenter模板中有 a 。
回答by Wobbles
I am pretty surprised nobody has mentioned to just edit the control template, all the other solutions have some pretty serious drawbacks weather its not calculating width properly, not redrawing, render time etc...
我很惊讶没有人提到只编辑控件模板，所有其他解决方案都有一些非常严重的缺点，因为它不能正确计算宽度，不能重绘，渲染时间等......
This control template will modify the header's contentpresenter horizontal alignment to match the actual expanders (meaning it will stretch)
此控制模板将修改标题的 contentpresenter 水平对齐方式以匹配实际扩展器（意味着它会拉伸）
<ControlTemplate x:Key="ExpanderControlTemplate1" TargetType="{x:Type Expander}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="3" SnapsToDevicePixels="True">
<DockPanel>
<ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" DockPanel.Dock="Top" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}">
<ToggleButton.FocusVisualStyle>
<Style>
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Border>
<Rectangle Margin="0" SnapsToDevicePixels="True" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ToggleButton.FocusVisualStyle>
<ToggleButton.Style>
<Style TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="19"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="1" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
<Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
<Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
<Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ToggleButton.Style>
</ToggleButton>
<ContentPresenter x:Name="ExpandSite" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" DockPanel.Dock="Bottom" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Visibility="Collapsed" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</DockPanel>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="True">
<Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
</Trigger>
<Trigger Property="ExpandDirection" Value="Right">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left"/>
<Setter Property="Style" TargetName="HeaderSite">
<Setter.Value>
<Style TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.RowDefinitions>
<RowDefinition Height="19"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<RotateTransform Angle="-90"/>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
<Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
<Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
<Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="ExpandDirection" Value="Up">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom"/>
<Setter Property="Style" TargetName="HeaderSite">
<Setter.Value>
<Style TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="19"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<RotateTransform Angle="180"/>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="1" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
<Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
<Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
<Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="ExpandDirection" Value="Left">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right"/>
<Setter Property="Style" TargetName="HeaderSite">
<Setter.Value>
<Style TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.RowDefinitions>
<RowDefinition Height="19"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<RotateTransform Angle="90"/>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="White" HorizontalAlignment="Center" Height="19" Stroke="#FF333333" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M1,1.5L4.5,5 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="False" Stroke="#FF333333" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Data" TargetName="arrow" Value="M1,4.5L4.5,1 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF5593FF"/>
<Setter Property="Fill" TargetName="circle" Value="#FFF3F9FF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Stroke" TargetName="circle" Value="#FF3C77DD"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="#FFD9ECFF"/>
<Setter Property="Stroke" TargetName="arrow" Value="Black"/>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Stroke" TargetName="circle" Value="#FFBCBCBC"/>
<Setter Property="Fill" TargetName="circle" Value="#FFE6E6E6"/>
<Setter Property="Stroke" TargetName="arrow" Value="#FF707070"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
