在WPF中动态绑定触发值

Question

I'm using ListView along with the GridView for displaying the data in tabular format:

<ListView>
 <ListView.View>
   <GridView>
     <GridViewColumn Header="Name" Width="120" DisplayMemberBinding="{Binding Name}" />
     <GridViewColumn Header="Risk" Width="150" DisplayMemberBinding="{Binding RiskName}" />
   </GridView>
</ListView.View>

I have to change the background color based on the RiskName . For example, if RiskName is "High" then the background would be Red, if RiskName is "Medium" then the background would be "Yellow", and so on.

I added the style along with trigger to set background based on the value,

<Trigger Property="Text" Value="High">
  <Setter Property="Background" Value="Red"/>
</Trigger>
<Trigger Property="Text" Value="Medium">
  <Setter Property="Background" Value="Yellow"/>
</Trigger>

It works fine, but in my case the text of the RiskName is not constant. The value comes dynamically. In WPF is there any way I can set the Value of trigger property dynamically which look something like this?

<Trigger Property="Text" Value="{Binding RiskName}">
    <Setter Property="Background" Value="{Binding RiskBrush}"/>
</Trigger>

Any suggestion? If not then what is the other work around?

Answer 1

Use a Converter instead of a Trigger . Bind the Background to RiskName and write a converter that returns a Brush determined by the value of RiskName .

Link to MSDN for the interface you need to use IValueConverter - http://msdn.microsoft.com/en-us/library/system.windows.data.ivalueconverter%28v=vs.110%29.aspx

A link to a good tutorial on Converters: http://wpftutorial.net/ValueConverters.html

Answer 2

Something like this?

<converters:MyBrushLookupConverter x:Key="brushLookup" BrushDictionary="{Binding KeyedBrushes}" />

where MyBrushLookupConverter looks like

public class MyBrushLookupConverter : DependencyObject, IValueConverter
{
   // This is a dependency property - dependency property gumf omitted for brevity
   public Dictionary<string, Brush> BrushDictionary {get; set;}

   // Convert method
   public Convert(object value, ...)
   {
      return BrushDictionary[(string)value];
   }
}