问题描述
如何通过 GridView 获取 ListView 的标题高度?它甚至有可能吗?
我需要根据 ListView 所以我开始写一个 Converter 。问题是我无法访问实际高度。
Visual Studio的调试器显示 GridView 有一个名为 HeaderRowPresenter 的属性,该属性又具有属性 ActualHeight 。但我无法访问它, HeaderRowPresenter 似乎是受保护或私有的。
所有其他 ColumnHeader * 属性( ColumnHeaderContainerStyle , ColumnHeaderTemplate 等)都是 对于所有 Header * 属性在 Columns (除了作为标题内容的 String )。
顺便说一句:我试图解决一个和我目前的方法让我这样做,所以也许我采取了错误的方式。
好的,我找到了解决方案,但我不是很自豪,因为它使用反射:
我写了 Converter 一个 View 和一个 ListView 作为值和参数,并返回高度t
public class HeightSyncConverter:IValueConverter
{
public object Convert(object value ,类型targetType,对象参数,CultureInfo culture)
{
GridView gvLocal = value作为GridView;
ListView lvOther =参数为ListView;
if(gvLocal == null || lvOther == null)
{
return 0;
}
GridView gvOther =(GridView)lvOther.View;
try
{
//获取非公共HeaderRowPresenter属性
GridViewHeaderRowPresenter hrpLocal =(GridViewHeaderRowPresenter)gvLocal.GetType()。GetProperty(HeaderRowPresenter,BindingFlags.NonPublic | BindingFlags .Instance).GetValue(gvLocal);
GridViewHeaderRowPresenter hrpOther =(GridViewHeaderRowPresenter)gvOther.GetType()。GetProperty(HeaderRowPresenter,BindingFlags.NonPublic | BindingFlags.Instance).GetValue(gvOther);
if(hrpLocal == null || hrpOther == null)
{
return 0;
}
//只有在其他ListView的标题高于本地
的情况下才有效if(hrpLocal.ActualHeight> hrpOther.ActualHeight)
{
返回0;
}
return hrpOther.ActualHeight - hrpLocal.ActualHeight;
}
catch(TargetInvocationException){}
return 0;
公共对象ConvertBack(对象值,类型targetType,对象参数,CultureInfo culture)
{
return null;
}
}
然后我用它来定义 Grid.Row :
< UserControl x:Class =GUI。 ListViewLayout
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:GUI
xmlns:conv =clr-namespace:GUI.Converter
mc:Ignorable =dd:DesignHeight = 300d:DesignWidth =300
Loaded =Window_Loaded>
< UserControl.Resources>
< Style x:Key =verticalGridViewColumnHeaderTargetType =GridViewColumnHeader>
< Setter Property =ContentTemplate>
< Setter.Value>
< DataTemplate>
< TextBlock Text ={Binding}FontWeight =Bold
VerticalAlignment =CenterTextAlignment =CenterHorizontalAlignment =Center>
< TextBlock.LayoutTransform>
< RotateTransform Angle =270/>
< /TextBlock.LayoutTransform>
< / TextBlock>
< / DataTemplate>
< / Setter>
< / style>
< conv:HeightSyncConverter x:Key =myConverter/>
< /UserControl.Resources>
< Grid x:Name =grid>
< Grid.ColumnDefinitions>
< ColumnDefinition Width =150/>
< ColumnDefinition Width =150/>
< /Grid.ColumnDefinitions>
< Grid.RowDefinitions>
< RowDefinition Height =Auto/>
< RowDefinition x:Name =fillerRowHeight ={Binding View,ElementName = listView1,Converter = {StaticResource myConverter},ConverterParameter = {x:Reference listView2}}/>
< RowDefinition Height =*/>
< /Grid.RowDefinitions>
< Button x:Name =someControlGrid.RowSpan =2>占位符< / Button>
< ListView x:Name =listView1Grid.Row =2>
< ListView.View>
< GridView>
< GridViewColumn Header =Header 1Width =60/>
< GridViewColumn Header =Header 2Width =60/>
< / GridView>
< /ListView.View>
< / ListView>
< ListView x:Name =listView2Grid.Row =1Grid.Column =1Grid.RowSpan =2>
< ListView.View>
< GridView>
< GridViewColumn Header =Long Header 1
HeaderContainerStyle ={StaticResource verticalGridViewColumnHeader}Width =Auto/>
< GridViewColumn Header =Long Header 2
HeaderContainerStyle ={StaticResource verticalGridViewColumnHeader}Width =Auto/>
< / GridView>
< /ListView.View>
< / ListView>
< / Grid>
< / UserControl>
问题是转换器在 ListView s和它们的头文件被初始化了,所以我重新评估了代码隐藏中的 Binding :
<$ p $用户控件
{
public ListViewLayout()
{
InitializeComponent();
private void Window_Loaded(object sender,RoutedEventArgs e)
{
BindingExpression binding = fillerRow.GetBindingExpression(RowDefinition.HeightProperty);
binding.UpdateTarget();
}
}
总而言之,我不认为这是值得付出努力,最好的方法是自己定义标题的高度,而不是检索自动计算的 ActualHeight 。
How can I get the height of the header of a ListView with a GridView? Is it even possible?
I need to set the height of one control based on the height of the header of a ListView so I started writing a Converter. The problem is that I can't access the actual height.
The debugger of Visual Studio shows me that GridView has a property called HeaderRowPresenter, which in turn has a property ActualHeight. But I can't access it, HeaderRowPresenter seems to be protected or private.
All other ColumnHeader* properties (ColumnHeaderContainerStyle, ColumnHeaderTemplate, etc.) are null on this object, same for all Header* properties on the Columns (except for the String that is the content of the header).
Btw: I'm trying to solve a different problem and my current approach let me to this, so maybe I'm taking this on the wrong way.
Okay, I've found a solution but I'm not very proud of it, because it uses reflection:
I wrote a Converter that takes a View and a ListView as value and parameter and returns the height difference of the headers:
public class HeightSyncConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { GridView gvLocal = value as GridView; ListView lvOther = parameter as ListView; if( gvLocal == null || lvOther == null) { return 0; } GridView gvOther = (GridView)lvOther.View; try { // get the non-public HeaderRowPresenter property GridViewHeaderRowPresenter hrpLocal = (GridViewHeaderRowPresenter)gvLocal.GetType().GetProperty("HeaderRowPresenter", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(gvLocal); GridViewHeaderRowPresenter hrpOther = (GridViewHeaderRowPresenter)gvOther.GetType().GetProperty("HeaderRowPresenter", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(gvOther); if( hrpLocal == null || hrpOther == null ) { return 0; } // Only works if the other ListView's header is higher than the local one's if( hrpLocal.ActualHeight > hrpOther.ActualHeight ) { return 0; } return hrpOther.ActualHeight - hrpLocal.ActualHeight; } catch(TargetInvocationException) { } return 0; } public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { return null; } }
I then use it to define the height of a Grid.Row:
<UserControl x:Class="GUI.ListViewLayout" 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:GUI" xmlns:conv="clr-namespace:GUI.Converter" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300" Loaded="Window_Loaded"> <UserControl.Resources> <Style x:Key="verticalGridViewColumnHeader" TargetType="GridViewColumnHeader"> <Setter Property="ContentTemplate"> <Setter.Value> <DataTemplate> <TextBlock Text="{Binding}" FontWeight="Bold" VerticalAlignment="Center" TextAlignment="Center" HorizontalAlignment="Center"> <TextBlock.LayoutTransform> <RotateTransform Angle="270" /> </TextBlock.LayoutTransform> </TextBlock> </DataTemplate> </Setter.Value> </Setter> </Style> <conv:HeightSyncConverter x:Key="myConverter" /> </UserControl.Resources> <Grid x:Name="grid"> <Grid.ColumnDefinitions> <ColumnDefinition Width="150" /> <ColumnDefinition Width="150" /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition x:Name="fillerRow" Height="{Binding View, ElementName=listView1, Converter={StaticResource myConverter}, ConverterParameter={x:Reference listView2}}" /> <RowDefinition Height="*" /> </Grid.RowDefinitions> <Button x:Name="someControl" Grid.RowSpan="2">Placeholder</Button> <ListView x:Name="listView1" Grid.Row="2"> <ListView.View> <GridView> <GridViewColumn Header="Header 1" Width="60"/> <GridViewColumn Header="Header 2" Width="60" /> </GridView> </ListView.View> </ListView> <ListView x:Name="listView2" Grid.Row="1" Grid.Column="1" Grid.RowSpan="2"> <ListView.View> <GridView> <GridViewColumn Header="Long Header 1" HeaderContainerStyle="{StaticResource verticalGridViewColumnHeader}" Width="Auto" /> <GridViewColumn Header="Long Header 2" HeaderContainerStyle="{StaticResource verticalGridViewColumnHeader}" Width="Auto" /> </GridView> </ListView.View> </ListView> </Grid> </UserControl>
The problem is that the converter is called before the ListViews and their headers are initialized, so I reevaluate the Binding in the code-behind:
public partial class ListViewLayout : UserControl { public ListViewLayout() { InitializeComponent(); } private void Window_Loaded(object sender, RoutedEventArgs e) { BindingExpression binding = fillerRow.GetBindingExpression(RowDefinition.HeightProperty); binding.UpdateTarget(); } }
All in all, I don't think this is worth the effort and the best way is to define the height of the headers myself instead of retrieving an automatically calculated ActualHeight.
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