Question

Somehow WPF Canvas has a lot of items which are NULL.

Is there some way to delete/remove it?

Answer 1

I am assuming your Canvas has null items because it is bound to a data source that has null items

It would be far better to remove the null items from the data source before binding the data, however if that isn’t possible, then try using a Converter that removes null items from the collection to do the binding.

All it really needs to do is loop through the items and check if each one is null. If so, remove it using .RemoveAt(index)

var i = 0;
while(i < list.Items.Count)
{
    if (list.items[i] == null)
        list.RemoveAt(i);
    else
        i++; // don't increase i if you're removing an item
}