EventHandler in WPF - Change in one element affects another-CodePudding

I have a stackpanel with a TextBlock and a ComboxBox and the I have a TextBox acting as a search field.

<StackPanel Grid.Row="1" Grid.Column="2">
    <TextBlock Text="Group Filter" Margin="7,0,0,0"/>
    <ComboBox Text ="{Binding GroupFilter}" Height="30" Width="130" Margin="0,4,0,0" 
        Padding="5" IsSynchronizedWithCurrentItem="True"
        ItemsSource="{Binding Source={StaticResource GroupFilterEnum}}"
    </ComboBox>
</StackPanel>

<TextBox Text="{Binding SingleFilter, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Grid.Row="1" Grid.Column="3" Height="30" Width="140" Margin="0,20,0,0" Padding="5" materialDesign:HintAssist.Hint="Search single Id...">
</TextBox>

So basically I have a data set and what you can do is you can filter the data based on either a predefined setting from theGroupFilterEnum or you can enter a filter value yourself in the TextBox.

What I try to do is:

When the TextBox is empty things should just be as they are. When the TextBox has a value I would like to add the following to the ComboBox to indicate that the ComboBox is inactive when there is a value in the TextBox:

IsEditable="False" 
IsHitTestVisible="False" 
Focusable="False" 
Foreground="{StaticResource MaterialDesignBodyLight}"

I have tried to make an TextChanged EventHandler for the TextBox like:

private void textChangedEventHandler(object sender, TextChangedEventArgs args)
{
    var text = sender.ToString().Replace("System.Windows.Controls.TextBox: ", "");

    if (!string.IsNullOrWhiteSpace(text))
    {

    }
}

But I don't really know how to refer to the ComboBox from this EventHandler. I am fairly new to this, so I haven't reallty done a lot of EventHandlers. Is this the way to do it? If yes, could someone please help me with the Eventhandler? Or maybe there is a better way? Directly in the xaml file maybe?

All help is highly appreciated and please let me know if additional information is needed.

Thanks in advance.

CodePudding user response：

You could bind the ComboBox properties you want to change to the Text property of the TextBox using a converter that you would need to implement (here is the example).

<TextBox x:Name="MyTextBox"/>
<ComboBox Focusable="{Binding ElementName=MyTextBox, Path=Text, Converter={StaticResource EmptyStringToBooleanConverter}}">

CodePudding user response：

If you want a control that can be used like a textBox or comboBox, you are not in the good way.

The comboBox control have a property IsEditable which permit to write or select a value.

Try this : <ComboBox IsEditable="True"/>

Else, you can give a name to your control and you will able to get it in your code behind by typing his name.

The result here : Result (And I'm sorry for my english, I'm french).