How to bind multiple selection of listview to viewmodel?

Question

I am implementing a listview, and a button next to it. I have to be able that when i select multiple items in a listview, and then click on a button, then the selected items are put into a list. But my question is , how do i bind the selected items towards the viewmodel? I changed my selectionmode to multiple. But then, do i just have to do:

SelectedItem={Binding path= selectedItems}

and then make in my viewmodel a property selectedItems, and it will set these items i have selected? Or what is the right solution to do this?

Answer 1

Like Doctor has already pointed out, you can bind SelectedItems to XAML CommandParameter

After a lot of digging and googling, I have finally found a simple solution to this common issue.

To make it work you must follow ALL the following rules:

1. Following Ed Ball's suggestion', on you XAML command databinding, define CommandParameter property BEFORE Command property. This a very time-consuming bug.

   

2. Make sure your ICommand's CanExecute and Execute methods have a parameter of object type. This way you can prevent silenced cast exceptions that occurs whenever databinding CommandParameter type does not match your command method's parameter type.

   private bool OnDeleteSelectedItemsCanExecute(object SelectedItems)
   {
       // Your goes here
   }
   
   private bool OnDeleteSelectedItemsExecute(object SelectedItems)
   {
       // Your goes here
   }
   

For example, you can either send a listview/listbox's SelectedItems property to you ICommand methods or the listview/listbox it self. Great, isn't it?

Hope it prevents someone spending the huge amount of time I did to figure out how to receive SelectedItems as CanExecute parameter.