c# - 基于项目属性的网格背景颜色

Question

如何根据单个项目的属性设置单个网格项目的背景颜色？我有以下代码:

<PivotItem x:Uid="PivotBlocks" Margin="10, 10, 10, 10" Header="blockx" DataContext="{Binding Blocks}" d:DataContext="{Binding , Source={d:DesignData Source=/DataModel/SampleData.json, Type=data:DataSource}}">
    <GridView ItemsSource="{Binding Formations}" IsItemClickEnabled="True" ItemClick="Point_ItemClick" Loaded="PivotBlocks_Loaded" ContinuumNavigationTransitionInfo.ExitElementContainer="True">
        <GridView.ItemTemplate>
            <DataTemplate>
                <Grid Width="80" Height="80" Margin="0,0,10,10" Background="{StaticResource PhoneAccentBrush}">
                    <StackPanel VerticalAlignment="Bottom">
                        <TextBlock Text="{Binding Shorthand}" Padding="5, 0, 0, 5" Style="{StaticResource SubheaderTextBlockStyle}" />
                    </StackPanel>
                </Grid>
            </DataTemplate>
        </GridView.ItemTemplate>
    </GridView>
</PivotItem>

每个队形(项目)都有一个HasBeenSelected类型的Bool属性，我想使用该属性来设置颜色，如果为true，则为灰色，否则用户会加重颜色。

Answer 1

例如，您可以将Converter用于此任务:

在 namespace 中定义转换器类:

namespace MyConverters
{
  public class BoolToBrush : IValueConverter
  {
    private Brush FalseValue = new SolidColorBrush(Colors.Gray);
    public Brush TrueValue = Application.Current.Resources["PhoneAccentBrush"] as Brush;

    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (value == null) return FalseValue;
        else return (bool)value ? TrueValue : FalseValue;
    }

    public object ConvertBack(object value, Type targetType, object parameter, string language)
    {
        return value != null ? value.Equals(TrueValue) : false;
    }
  }
}

然后在XAML中的Page.Resources中定义一个键(不要忘记添加 namespace ):

<Page ...
      ... some code ...
 xmlns:converter="MyConverters"
      .../>
<Page.Resources>
    <converter:BoolToBrush x:Key="BoolToBrush"/>
</Page.Resources>

最后，您可以将转换器与Binding一起使用:

<PivotItem x:Uid="PivotBlocks" Margin="10, 10, 10, 10" Header="blockx" DataContext="{Binding Blocks}" d:DataContext="{Binding , Source={d:DesignData Source=/DataModel/SampleData.json, Type=data:DataSource}}">
    <GridView ItemsSource="{Binding Formations}" IsItemClickEnabled="True" ItemClick="Point_ItemClick" Loaded="PivotBlocks_Loaded" ContinuumNavigationTransitionInfo.ExitElementContainer="True">
        <GridView.ItemTemplate>
            <DataTemplate>
                <Grid Width="80" Height="80" Margin="0,0,10,10" Background="{Binding HasBeenSelected, Converter={StaticResource BoolToBrush}}">
                    <StackPanel VerticalAlignment="Bottom">
                        <TextBlock Text="{Binding Shorthand}" Padding="5, 0, 0, 5" Style="{StaticResource SubheaderTextBlockStyle}" />
                    </StackPanel>
                </Grid>
            </DataTemplate>
        </GridView.ItemTemplate>
    </GridView>
</PivotItem>