[Solved] DataFormComboBoxField event question

[Art Kedzierski]

Does the DataFormComboBoxField support the SelectionChanged event? I'm trying to change a related DataFormComboBoxField (actually, a four-tier hierarchical tree) and it's not working as expected. I'm using MVVM.

<telerik:DataFormComboBoxField Label="Vendor (Required):"
                               DataMemberBinding="{Binding Vendor, Mode=TwoWay}"
                               ItemsSource="{Binding ElementName=LayoutRoot, Path=DataContext.Vendors}"
                               SelectedValuePath="Vendor"
                               DisplayMemberPath="Vendor">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="SelectionChanged">
            <ei:CallMethodAction TargetObject="{Binding}"
                                 MethodName="GetProducts"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</telerik:DataFormComboBoxField>
<telerik:DataFormComboBoxField Label="Product (Required):"
                               DataMemberBinding="{Binding Product, Mode=TwoWay}"
                               ItemsSource="{Binding ElementName=LayoutRoot, Path=DataContext.Products}"
                               SelectedValuePath="Product"
                               DisplayMemberPath="Product"
                               IsEnabled="{Binding ElementName=LayoutRoot, Path=DataContext.ProductsEnabled}">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="SelectionChanged">
            <ei:CallMethodAction TargetObject="{Binding}"
                                 MethodName="GetComponents"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</telerik:DataFormComboBoxField>
<telerik:DataFormComboBoxField Label="Component:"
                               DataMemberBinding="{Binding Component, Mode=TwoWay}"
                               ItemsSource="{Binding ElementName=LayoutRoot, Path=DataContext.Components}"
                               SelectedValuePath="Component"
                               DisplayMemberPath="Component"
                               IsEnabled="{Binding ElementName=LayoutRoot, Path=DataContext.ComponentsEnabled}">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="SelectionChanged">
            <ei:CallMethodAction TargetObject="{Binding}"
                                 MethodName="GetVersions"/>
        </i:EventTrigger>
    </i:Interaction.Triggers>
</telerik:DataFormComboBoxField>
<telerik:DataFormComboBoxField Label="Version:"
                               DataMemberBinding="{Binding Version, Mode=TwoWay}"
                               ItemsSource="{Binding ElementName=LayoutRoot, Path=DataContext.Versions}"
                               SelectedValuePath="Version"
                               DisplayMemberPath="Version"
                               IsEnabled="{Binding ElementName=LayoutRoot, Path=DataContext.VersionsEnabled}">
</telerik:DataFormComboBoxField>

[Maya]

Hello Art,

You can add handler for RadComboBox SelectionChanged event as illustrated in this article. 

Regards,
Maya
Telerik

[Art Kedzierski]

Is there an MVVM way to do that or just code-behind? 

[Art Kedzierski]

Also, that article is for a GridViewComboBoxColumn. Is the process the same for DataFormComboBoxField? Do I need to add a separate handler for each DataFormComboBoxField?

[Maya]

Hi Art,

The same approach as the one illustrated in the article can be applied for data form and you need to add the handler only once. The event will be fired for selection change of each DataFormComboBoxField.
If you do not want to implement that logic in your code-behind, you can try creating an attached behavior and place it there. 

Regards,
Maya
Telerik