Question

Have a little problem with hooking up the keydown event without codebehind!
So, we have the combobox

<ComboBox Height="20" Width="auto"
                  ItemsSource="{Binding AlignComboItems}"
                  SelectedValue="{Binding SelectedComboItem, Mode=TwoWay}"
                  SelectedValuePath="Key" DisplayMemberPath="Value"

                  SelectedItem="{Binding SelectedItem}"
                  x:Name="cmbBoxAlign">
</ComboBox>

and some TextBox.

<TextBox Text={Binding SomeSource}></TextBox>

How to catch the keydown event on the TextBox for selecting the (for example) the last element in ComboBox? I cant use the TextBox DataSource property changing, because need hook the user input up.

Answer 1

If you don’t mind installing the Expression Blend SDK you should be able to do this in your textbox

<i:Interaction.Triggers>
    <i:EventTrigger EventName="KeyUp">
        <i:InvokeCommandAction Command="{Binding Path=TheCommand}" />
    </i:EventTrigger>
</i:Interaction.Triggers>

After adding a reference to System.Windows.Interactivity and the following namespace in your xaml

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"

Link to the Expression SDK for 4.0

http://www.microsoft.com/en-us/download/details.aspx?id=10801