我在SemanticZoom控件中有一个GridView作为缩小视图。此GridView使用自定义DataTemplateSelector作为ItemTemplateSelector。 DataTemplateSelector返回具有不同Foreground颜色的DataTemplate，具体取决于Group是否包含任何项目。
但是，即使DataTemplateSelector似乎工作并返回正确的模板，GridView也只使用一个模板，并且文本颜色相同。
这是GroupedListView的XAML：
<UserControl
x:Class="GroupList.GroupList.GroupedListView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:GroupList.GroupList"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:data="using:GroupList.Model"
xmlns:wuxdata="using:Windows.UI.Xaml.Data"
mc:Ignorable="d">
<UserControl.Resources>
<!-- Use a collection view source for content that presents itself as a list of items that can be grouped or sorted. Otherwise, you can use x:Bind
directly on the ListView's item source to for further optimization. Please see the AppUIBasics sample for an example of how to do this. -->
<CollectionViewSource x:Name="ContactsCVS" IsSourceGrouped="True" />
<Style TargetType="TextBlock" x:Key="TileHeaderTextStyle" BasedOn="{StaticResource ProximaNovaSemiBold}">
<Setter Property="FontSize" Value="54" />
<Setter Property="Foreground" Value="White" />
<Setter Property="FontWeight" Value="ExtraBold"/>
<Setter Property="FontStretch" Value="Expanded" />
</Style>
<Style TargetType="TextBlock" x:Key="TileHeaderTextStyleGray" BasedOn="{StaticResource TileHeaderTextStyle}">
<Setter Property="Foreground" Value="Khaki" />
</Style>
<!-- When using x:Bind, you need to set x:DataType -->
<DataTemplate x:Name="ContactListViewTemplate" x:DataType="data:Contact">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Ellipse x:Name="Ellipse"
Grid.RowSpan="2"
Width ="32"
Height="32"
Margin="6"
VerticalAlignment="Center"
HorizontalAlignment="Center"
Fill="LightGray"/>
<TextBlock Grid.Column="1"
Text="{x:Bind Name}"
x:Phase="1"
Style="{ThemeResource BaseTextBlockStyle}"
Margin="12,6,0,0"/>
<TextBlock Grid.Column="1"
Grid.Row="1"
Text="{x:Bind Position}"
x:Phase="2"
Style="{ThemeResource BodyTextBlockStyle}"
Margin="12,0,0,6"/>
</Grid>
</DataTemplate>
<DataTemplate x:Key="GrayZoomedOutTemplate" x:DataType="wuxdata:ICollectionViewGroup">
<TextBlock Text="{x:Bind Group.(data:GroupInfoList.Key)}" Margin="0,0,0,5" Style="{StaticResource TileHeaderTextStyleGray}" />
</DataTemplate>
<DataTemplate x:Key="ZoomedOutTemplate" x:DataType="wuxdata:ICollectionViewGroup">
<TextBlock Text="{x:Bind Group.(data:GroupInfoList.Key)}" Margin="0,0,0,5" Style="{StaticResource TileHeaderTextStyle}" />
</DataTemplate>
<local:GroupEmptyOrFullSelector x:Key="GroupEmptyOrFullSelector" Empty="{StaticResource GrayZoomedOutTemplate}" Full="{StaticResource ZoomedOutTemplate}" />
</UserControl.Resources>
<!--#region Navigation Panel -->
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel Orientation="Vertical">
<TextBlock Margin="15,0,0,0" Text="Paula's SemanticZoom Sandbox" Grid.Row="0"
VerticalAlignment="Center"
Style="{ThemeResource TitleTextBlockStyle}" />
<Button x:Name="ZoomInOutBtn" Content="ABC↕" Click="ZoomInOutBtn_Click" Width="60" HorizontalAlignment="Center" BorderThickness="0" />
</StackPanel>
<!--#endregion-->
<SemanticZoom x:Name="ZoomControl" Grid.Row="1">
<SemanticZoom.ZoomedInView>
<GridView ItemsSource="{x:Bind ContactsCVS.View}"
ItemTemplate="{StaticResource ContactListViewTemplate}"
SelectionMode="Single"
ShowsScrollingPlaceholders="True">
<GridView.GroupStyle>
<GroupStyle HidesIfEmpty="True">
<GroupStyle.HeaderTemplate>
<DataTemplate x:DataType="data:GroupInfoList">
<TextBlock Text="{x:Bind Key}"
Style="{ThemeResource TitleTextBlockStyle}" />
</DataTemplate>
</GroupStyle.HeaderTemplate>
</GroupStyle>
</GridView.GroupStyle>
</GridView>
</SemanticZoom.ZoomedInView>
<SemanticZoom.ZoomedOutView>
<GridView ItemTemplateSelector="{StaticResource GroupEmptyOrFullSelector}" ScrollViewer.VerticalScrollBarVisibility="Disabled" Margin="0, 200" Width="475" ItemsSource="{x:Bind ContactsCVS.View.CollectionGroups}" SelectionMode="None" >
</GridView>
</SemanticZoom.ZoomedOutView>
</SemanticZoom>
</Grid>
</UserControl>
这是DataTemplateSelector：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.Foundation.Collections;
using GroupList.Model;
namespace GroupList.GroupList
{
/// <summary>
/// This determines whether or not the Group passed during binding is empty or not and allows selection
/// of the proper DataTemplate based on this value.
/// </summary>
class GroupEmptyOrFullSelector : DataTemplateSelector
{
private DataTemplate _full;
private DataTemplate _empty;
public DataTemplate Full
{
set { _full = value; }
get { return _full; }
}
public DataTemplate Empty
{
set { _empty = value; }
get { return _empty; }
}
protected override DataTemplate SelectTemplateCore(object item, DependencyObject container)
{
var itemType = item.GetType();
var isGroup = itemType.Name == "GroupInfoList";
bool isEmpty = false;
GroupInfoList groupItem;
if (isGroup)
{
groupItem = item as GroupInfoList;
isEmpty = groupItem.Count == 0;
}
// Disable empty items
var selectorItem = container as SelectorItem;
if (selectorItem != null)
{
selectorItem.IsEnabled = !isEmpty;
}
if (isEmpty)
{
return Empty;
}
else
{
return Full;
}
}
}
}
答案 0 :(得分：0)
所以，问题出在这里：
在DataTemplateSelector列表中，即使传递了＆＃34;对象项＆＃34;它不是一个群体，它落到了模板选择逻辑中。有时，＆＃34;对象＆＃34;传递给你的函数不是一个Group对象，而是一个通用的DependencyObject。在这种情况下，模板选择逻辑需要返回默认模板，仅当＆＃34;对象项＆＃34;返回时才返回其中一个特定模板。是一个Group对象。因此，新函数如下所示：
for idx, item in enumerate(data):
if item == inputo:
print(idx)
else:
print("not found")