Question

I have a simple conditional, a textbox named tbDestinationTableName that should only allow user input when any selection is made from the the ComboBox cbConnection. I currently do this in codeBehind. Can some one correct the following code if this can be done in XAML?

<ComboBox x:Name="cbConnection"
                  ItemsSource="{Binding Source={StaticResource XmlConnectionList}, XPath=//ComboItem}"
                  DisplayMemberPath="Key"
                  SelectedValuePath="Value"
                  SelectedValue="{Binding Path=ConnectionString,ValidatesOnDataErrors=True,UpdateSourceTrigger=PropertyChanged}" 
                  Margin="{StaticResource ConsistentMargins}"
                  />

<kit:WatermarkTextBox Name="tbDestinationTableName" Margin="{StaticResource ConsistentMargins}"
                  TextChanged="tbDestinationTableName_TextChanged"
                  Text="{Binding Path=DestinationTableName, UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=True}"
                  Watermark="Destination Table"
                  IsEnabled="{Binding Path=ValidCreate}"/>

Answer 1

i believe you can do something like this with your custom textbox

<kit:WatermarkTextBox>
    <kit:WatermarkTextBox.Style>
        <Style TargetType="{x:Type kit:WatermarkTextBox}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding ElementName=cbConnection, Path=SelectedIndex}" Value="-1">
                    <Setter Property="IsReadOnly" Value="True"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </kit:WatermarkTextBox.Style>
</kit:WatermarkTextBox>

If you want to use IsEnabled instead then it should not be set in kit:WatermarkTextBox’s xaml.

Just use another Datatrigger like this:

   <kit:WatermarkTextBox Name="tbDestinationTableName" Margin="{StaticResource ConsistentMargins}"                     
                TextChanged="tbDestinationTableName_TextChanged"
                Text="{Binding Path=DestinationTableName, UpdateSourceTrigger=PropertyChanged,ValidatesOnDataErrors=True}"
              Watermark="Destination Table">
    <kit:WatermarkTextBox.Style>
        <Style TargetType="{x:Type kit:WatermarkTextBox}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding ElementName=cbConnection, Path=SelectedIndex}" Value="-1">
                    <Setter Property="IsEnabled" Value="False"/>
                </DataTrigger>
                <DataTrigger Binding="{Binding Path=ValidCreate}" Value="False">
                    <Setter Property="IsEnabled" Value="False"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </kit:WatermarkTextBox.Style>
</kit:WatermarkTextBox>