Question

I have a radgrid, for date column i have created a custom user control for filtering. I need to create a close button to close the user control. There are no close events which i can call. I don’t want to make visibility collapsed. I started with something below:

public partial class DateFilterControl : UserControl, IFilteringControl
{
    public event CloseEventHandler Close;
    public delegate void CloseEventHandler();

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        this.Close();            
    }
}

It is throwing nullreference exception which is obvious to come. What code do i need to put to close the user control?

Answer 1

use Messaging Service. With this you can close the window in ViewModel so no need to give close function in Backend. Add Command property to Cancel button

 <Button Content="Cancel" Command="{Binding CancelCommand}"/>

Now in the ViewModel add the RelayCommand property in that add

 Messenger.Default.Send<bool>(true, typeof(XViewModel));

Now in the BackEnd of this userControl adds following in the constructor.

 Messenger.Default.Register<bool>(this, typeof(ScheduleViewModel), (b) => 
                                        {
                                            if (b == true)
                                            {
                                                this.DialogResult = true;
                                            }
                                        });

Now u can close the Window…
This will surely helps u…