如何在TreeView的SelectedItemChanged事件上更改TreeViewItem背景颜色？ [英] How to change the TreeViewItem background Color on SelectedItemChanged event of TreeView?

问题描述

Hi


在WPF应用程序中，我使用的是TreeView，它与源绑定。我正在使用DataTrigger根据特定条件更改TreeViewItem的背景。这里我的DataTrigger代码

Hi
In a WPF application I am using a TreeView and it is bind with a source. I am using a DataTrigger to change the background of TreeViewItem based on certain condition. Here my DataTrigger Code

<DataTrigger Binding="{Binding Id, Converter={StaticResource TreeViewItemBackGroundConverter}}" Value="True">
                               <Setter Property="Background" Value="Red"/>
                               <Setter Property="Opacity" Value="0.75"/>
                               <Setter Property="ToolTip" Value="{Binding Id, Converter={StaticResource ErrorConverter}}"/>
                           </DataTrigger>

它在加载时效果很好，但现在我想在选择更改或项目属性更改时执行此操作。我想检查我使用上面的数据触发器选择项目的相同条件，并根据我想要更改背景的条件。



我尝试使用SelectedItemChanged事件但无法找到TreeViewItem。我正在为TreeViewItem使用ItemTemplate。我怎么能这样做？



请帮助我。

It Works perfect when loading but now I want to do it on selection change or items property change. I want to check the same condition that I am using with Data Trigger above to selected Item and based on condition I want to change the background.

I tried to use SelectedItemChanged event but not able to find the TreeViewItem. I am using a ItemTemplate for the TreeViewItem. How I can do this?

Please help me.

推荐答案

你需要改变xaml中 TreeView 的 ItemContainerStyle 。将背景属性绑定到项目视图模型中的字符串属性，并使用转换器将该字符串属性转换为 Brush 。然后，您可以在设置 IsSelected 属性时从视图模型中设置背景。以下是一些可能有用的代码片段。

You need to change the ItemContainerStyle of the TreeView in xaml. Bind the Background property to a string property in the item view model and use a converter to convert that string property into a Brush. You can then set the background from the view model when the IsSelected property is set. Here are some code snippets that may be useful.

<treeview.itemcontainerstyle>
      <style targettype="{x:Type TreeViewItem}">
       <setter property="Background" value="{Binding BackgroundColour, Converter={StaticResource BackgroundToColourConverter},Mode=OneWay}" />
       <setter property="IsExpanded" value="{Binding IsExpanded, Mode=TwoWay}" />
        <setter property="IsSelected" value="{Binding IsSelected, Mode=TwoWay}" />
       </style>
    </treeview.itemcontainerstyle>

 public class BackgroundToColourConverter : IValueConverter
   {
       public object Convert(object value, Type targetType,
    object parameter, CultureInfo culture)
       {
           string s = value as string;
         Color color;
           switch (s)
           {
               case "Green":
                   color = Colors.Green;
                   break;
               case "Red":
                   color = Colors.Red;
                   break;
               default:
                   color = Colors.White;
                   break;

           }
           return new SolidColorBrush(color);
       }

       public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
       {
          return null;
       }
   }

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