How to correctly pass some custom parameters to event handlers in WPF?

Question

What could be a correct way to assign parameters to objects in WPF window (objects as simple as rectangles) and pass them to event handlers on mouse clicks?

Thank you.

Answer 1

Here's one way:

Put this in the Window:

public static readonly RoutedUICommand clickCommand = new RoutedUICommand("TheCommand", "TheCommand", typeof(Window1));

void ClickRectangle(object sender, ExecutedRoutedEventArgs e)
{
    if (e.Parameter == null)
        return;
    MessageBox.Show("parameter = " + e.Parameter.ToString());
}

Then in the XAML:

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:my="clr-namespace:WpfApplication1"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <Rectangle Margin="50" Fill="Blue">
            <Rectangle.CommandBindings>
                <CommandBinding
                    Command="my:Window1.clickCommand" Executed="ClickRectangle" />
            </Rectangle.CommandBindings>
            <Rectangle.InputBindings>
                <MouseBinding MouseAction="LeftClick"
                              Command="my:Window1.clickCommand" CommandParameter="123" />
            </Rectangle.InputBindings>
        </Rectangle>
    </Grid>
</Window>