Multiple command parameters wpf button object

Mandar Jogalekar picture Mandar Jogalekar · Apr 11, 2013 · Viewed 39.8k times · Source

How can I send multiple parameters from Button in WPF? I am able to send single parameter which is value of TextBox properly. Here is the code.

XAML

<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="133,22,0,0"     Name="textBox1" VerticalAlignment="Top" Width="120" />
<Button Content="Button" Grid.Row="1" Height="23" Command="{Binding Path=CommandClick}" CommandParameter="{Binding Text,ElementName=textBox1}" HorizontalAlignment="Left" Margin="133,62,0,0" Name="button1" VerticalAlignment="Top" Width="75" />

Code behind

public ICommand CommandClick { get; set; }

this.CommandClick = new DelegateCommand<object>(AddAccount);

private void AddAccount(object obj)
{
    //custom logic
}

Answer

Ron.B.I picture Ron.B.I · Jul 6, 2013

Other than using the approach of defining properties in you class (let's call it your ViewModel) to be binded by your view, there are times (not common) where we don't wan't to do so, an important tool to know in these situations is the MultiBinding, so just for completeness sake , even though you are satisfied with the first option, I'll cover another approach.

so to answer your question:

1. MVVM Approach :

Use the MVVM approach and define properties to binded by your view, and use those properties in your ViewModel's command without the need for CommandParameters.

2. MultiBinding : (Can live happily with MVVM approach)

Passing the Command Parameter as a Multi Binded parameter as seen here:

 <Button Content="MultiBindingExample" Command="{Binding MyCommand}">
     <Button.CommandParameter>
         <MultiBinding Converter="{StaticResource MyMultiConverter}">
             <Binding Path="..." ElementName="MyTextBox"/>
             <Binding Path="..." ElementName="MySomethingElse"/>
         </MultiBinding>
     </Button.CommandParameter>
 </Button>

With your Converter Defined using the IMultiValueConverter Interface:

public class MyMultiConverter: IMultiValueConverter
{
    public object Convert(object[] values, ...)
    {
        return values.Clone();
    }
}

and for extracting the values: Simply refer to the parameter in your command as an Object[] and use the parameters in the same order as in the MultiBinding.