WPF，XAML:如何使用 ListBox ItemsSource 对象的属性绑定来设置 ListBoxItem 的样式? [英] WPF, XAML: How to style a ListBoxItem using binding on property of ListBox ItemsSource object?

问题描述

我有一个绑定到 LogMessages 的 ObservableCollection 的 ListBox.

I have a ListBox which is bound to ObservableCollection of LogMessages.

public ObservableCollection<LogMessage> LogMessages { get; set; }
public LogMessageData()
{
    this.LogMessages = new ObservableCollection<LogMessage>();
}

每条消息都有两个参数:

Each Message has two parameters:

public class LogMessage
{
    public string Msg { get; set; }
    public int Severity { get; set; }
    //code cut...
}

ListBox 充满了这些项目，我需要 color-code(更改 ListBoxItem 的 background color)列表，具体取决于LogMessage 项的 Severity 参数.

ListBox is getting filled with those Items, and I need to color-code (change a background color of ListBoxItem) list depending on a Severity parameter of a LogMessage item.

这是我现在在 XAML 中显示日志的用户控件:

Here's what I have now in XAML of user control showing the log:

    <UserControl.Resources>
    <AlternationConverter x:Key="BackgroundSeverityConverter">
        <SolidColorBrush>Green</SolidColorBrush>
        <SolidColorBrush>Yellow</SolidColorBrush>
        <SolidColorBrush>Red</SolidColorBrush>
    </AlternationConverter>
    <Style x:Key="BindingAlternation" TargetType="{x:Type ListBoxItem}">
        <Setter Property="Background" 
                Value="{Binding RelativeSource={RelativeSource TemplatedParent}, 
                Path=Severity, 
                Converter={StaticResource BackgroundSeverityConverter}}"/>
    </Style>
    <DataTemplate x:Key="LogDataTemplate">
        <TextBlock x:Name="logItemTextBlock" Width="Auto" Height="Auto" 
        Text="{Binding Msg}"/>
    </DataTemplate>
</UserControl.Resources>

还有一个实际的 ListBox:

and an actual ListBox:

<ListBox IsSynchronizedWithCurrentItem="True" 
    ItemTemplate="{DynamicResource LogDataTemplate}" 
    ItemsSource="{Binding LogFacility.LogMessages}" 
    x:Name="logListBox" Grid.Row="1" 
    ItemContainerStyle="{StaticResource BindingAlternation}" />

使用 AlternationConverter 是因为 message 的 Severity 参数是 Int (0..3) 类型，我们可以使用它轻松地在样式之间切换.

The AlternationConverter is used because the Severity parameter of message is of type Int (0..3), and we can easily switch between styles using that one.

这个概念很清楚，但到目前为止它对我不起作用.ListBoxItem 的背景颜色没有改变.

The concept is clear, but so far it does not work for me. The Background color of ListBoxItem did not change.

推荐答案

使用ItemContainerStyle:

<ListBox ItemsSource="{Binding LogMessages}">
    <ListBox.ItemContainerStyle>
        <Style TargetType="ListBoxItem">
            <Setter Property="Background" Value="{Binding Severity, Converter={StaticResource YourBackgroundConverter}}"/>
        </Style>
    </ListBox.ItemContainerStyle>
</ListBox>

这篇关于WPF，XAML:如何使用 ListBox ItemsSource 对象的属性绑定来设置 ListBoxItem 的样式?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！