How to call treeView.SelectedItemChanged programmatically

Question

In my program I would like to call to a SelectedItemChanged event using c# code-behind, I am just unsure about what to pass as parameters. This is for a TreeViewItem.

//Gets selected item in TreeView
private void TreeOne_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    MainWindowViewModel.SelectedItem = e.NewValue as TreeViewItem;
}

//I'm calling the SelectedItemChanged event from a RightButtonDown event
private void TreeOne_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
    TreeOne_SelectedItemChanged(/* What would go here? **/);
}

Also, when I try to build this I receive this compiler error that pretty much led to this question...

No overload for method TreeOne_SelectedItemChanged takes '0' arguments

I'm hoping that this is an easy question, but if I have not provided enough information, or haven't been clear enough please let me know.

Answer 1

Adding to @Bart Friederichs' answer and assuming that you have a reference to your TreeView, you could add the following method:

private void SetSelectedItem()
{
     MainWindowViewModel.SelectedItem = TreeOne.SelectedItem;
}

Then you can simply call this from wherever you like:

private void TreeOne_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{
    SetSelectedItem();
}

private void TreeOne_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
{
    SetSelectedItem();
}

Answer 2

The usual design pattern would be to call some kind of processing method, and not to "manually" fire events:

private TreeOne_SelectedItemChaned(object sender, 
                        RoutedPropertyChangedEventArgs<object> e) {
    processChange();
}

Then, from withing your code, you just call processChange(), no need to call TreeOne_SelectedItemChanged.

Answer 3

try to call

TreeOne_SelectedItemChanged(null, null);