Binding the Trigger value dynamic in WPF

问题

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?

回答1:

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];
   }
}

回答2:

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

来源：https://stackoverflow.com/questions/27444178/binding-the-trigger-value-dynamic-in-wpf

标签

wpf

data-binding

triggers

styles