CODEWITHSUNDEEP
wpfbindingdatacontextcontroltemplateivalueconverter
Aaron Arnold
Aaron Arnold

Reputation: 61

DataContext as Source for Converter Binding Within Resources

 <Canvas.DataContext>
  <ViewModels:VMSomeControl Model="{Binding RelativeSource={RelativeSource TemplatedParent}}" />
 </Canvas.DataContext>

 <!-- DataContext is not passed into these Instances.
      they also have no knowledge of their TemplatedParent. -->
 <Canvas.Resources>

  <!--  is there a way to use a binding that points to the datacontext within the resources ? -->
  <Converters:SomeConverter x:Key="someConverter" 
                            SomeProperty="{Binding Path=Model.SomeProperty}" />

  <!--  is there a way to point Directly to the TemplatedParent  ? -->
  <Converters:SomeConverter x:Key="someConverter" 
                            SomeProperty="{TemplateBinding SomeProperty}" />

 </Canvas.Resources>


 <SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter=0}" />

 <SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter=1}" />

</Canvas>

is it possible to use bindings that use either the dataContext or the TemplatedParent Within a ControlTemplate's Root Visuals resourecs ?

Upvotes: 6

Views: 13320

Answers (4)

Александр Д.
Александр Д.

Reputation: 11

SomeProperty="{Binding . ,Converter={StaticResource SomeConverter}, ConverterParameter=someParam}"

The dot is telling that you binding to datacontext

Upvotes: 1

Matrix
Matrix

Reputation: 123

Here is a simple and efficient way (that works for my app):

<DataGrid.Columns>
    <DataGridTextColumn Width="*" Header="ColumnHeader">
        <DataGridTextColumn.Binding>
            <Binding Converter="{StaticResource YourConverterKey}" ConverterParameter="DataContext"/>
        </DataGridTextColumn.Binding>
    </DataGridTextColumn>

Now you can use (value) in the Convertor method as your DataContext.

Upvotes: -3

Mart&#237;n Coll
Mart&#237;n Coll

Reputation: 3804

Previous answer is reeeeally really close. but the binding inside the multibinding should be :

<SomeFrameworkElement>
    <SomeFrameworkElement.SomeProperty>
        <MultiBinding Converter="{StaticResource someConverter}" >
            <Binding />
        </MultiBinding>        
    </SomeFrameworkElement.SomeProperty>
</SomeFrameworkElement>

that worked for me

Upvotes: 11

Jakob Christensen
Jakob Christensen

Reputation: 14956

If you want your value converter to be able to access the datacontext you may want to use ConverterParameter instead:

<SomeFrameworkElement SomeProperty="{Binding Path=Model.SomeOtherProperty, Converter={StaticResource someConverter}, ConverterParameter={Binding DataContext}}" />

The datacontext will then be passed on to your value converter as a parameter to your implementation of IValueConverter.Convert.

You may be able to pass bindable parameters to your valueconverter if you implement IMultiValueConverter and bind the parameters using the MultiBinding class in XAML:

<SomeFrameworkElement>
    <SomeFrameworkElement.SomeProperty>
        <MultiBinding Converter="{StaticResource someConverter}" >
            <Binding Path="DataContext"/>
        </MultiBinding>        
    </SomeFrameworkElement.SomeProperty>
</SomeFrameworkElement>

The binding elements of the <MultiBinding> element are passed to the Convert method of IMultiValueConverter as the values parameter. Convert has the following signature:

public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture);

Upvotes: 6

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