列表框项触发颜色变化

Question

我想基于使用MVVM

<Border Grid.Row="1" Width="300" Margin="0,0,20,0" BorderThickness="1,2,1,1" CornerRadius="5" BorderBrush="#FF999393" Background="#FFE9EDF1" > 
    <ListBox ItemsSource="{Binding LogMessageList, UpdateSourceTrigger=PropertyChanged}" Background="{x:Null}" Margin="3" BorderBrush="{x:Null}" FontSize="13.333" > 
     <ListBox.ItemContainerStyle> 
      <Style TargetType="ListBoxItem"> 
        <Setter Property="Foreground" Value="#FF403E3E" /> 
        <Style.Triggers> 
         <DataTrigger Binding="{Binding FatalError, UpdateSourceTrigger=PropertyChanged}" Value="Fatal"> 
         <Setter Property="Foreground" Value="Firebrick" /> 
         </DataTrigger> 
        </Style.Triggers> 
      </Style> 
     </ListBox.ItemContainerStyle>              
    </ListBox> 

我正确地设置属性的变化，但似乎没有任何一个触发改变项目的颜色列表框更改。

感谢

编辑： 仍停留。尝试

<ListBox.ItemContainerStyle> 
    <Style TargetType="ListBoxItem"> 
     <Setter Property="Foreground" Value="#FF403E3E" /> 
      <Style.Triggers> 
       <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext.FatalError, UpdateSourceTrigger=PropertyChanged}" Value="Fatal"> 
      <Setter Property="Foreground" Value="Firebrick" /> 
     </DataTrigger> 
     </Style.Triggers> 
    </Style> 
</ListBox.ItemContainerStyle> 

Answer 1

试过你的情况。请参考下面的代码示例：

视图模型

public class Vm : INotifyPropertyChanged 
{ 
    public ObservableCollection<VmUser> VmUsers { get; set; } 

    private string errorType; 

    public string ErrorType 
    { 
     get { return errorType; } 
     set 
     { 
      errorType = value; 
      Raise("ErrorType"); 
     } 
    } 


    public event PropertyChangedEventHandler PropertyChanged; 

    public void Raise(string propertyName) 
    { 
     if (PropertyChanged != null) 
     { 
      PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
     } 
    } 
} 

public class VmUser 
{ 
    public string Name { get; set; } 

    public int Age { get; set; } 
} 

设置窗口的构造函数中DataContext：

public MainWindow() 
    { 
     Vm = new Vm 
     { 
      VmUsers = new ObservableCollection<VmUser> 
      { 
       new VmUser { Name = "Gil", Age = 1 }, 
       new VmUser { Name = "Dan", Age = 2 }, 
       new VmUser { Name = "John", Age = 3 }, 
      }, 

      ErrorType = "Fatal" 
     }; 
     InitializeComponent(); 
     DataContext = TheVm; 
    } 

在XAML定义ListBox为：

<ListBox Grid.Row="2" ItemsSource="{Binding VmUsers}" DisplayMemberPath="Name" SelectedValuePath="Age"> 
      <ListBox.ItemContainerStyle> 
       <Style TargetType="ListBoxItem"> 
        <Setter Property="Foreground" Value="#FF403E3E" /> 
        <Style.Triggers> 
         <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Window}},Path=DataContext.ErrorType, UpdateSourceTrigger=PropertyChanged}" Value="Fatal"> 
          <Setter Property="Foreground" Value="Red" /> 
         </DataTrigger> 
        </Style.Triggers> 
       </Style> 
      </ListBox.ItemContainerStyle> 
     </ListBox> 

为了测试th e我已经写了一个小测试来切换错误类型，点击按钮

private void Button_Click(object sender, RoutedEventArgs e) 
{ 
    var vm = this.DataContext as Vm; 
    if (vm != null) 
    { 
     if (vm.ErrorType == "Fatal") 
     { 
      vm.ErrorType = "Non Fatal"; 
     } 
     else 
     { 
      vm.ErrorType = "Fatal"; 
     } 
    } 
} 

上面的例子中前景色根据ErrorType改变。