Question

I’m pretty new to C#/WPF, coming from Obj-c background. I’m not really sure how this works in terms of object oriented design, and how different classes see each other.

So I have a large view (MainView) that has some custom plots and a datagrid on the bottom (Datagrid is in its separate xaml and has .cs file behind it). There is a custom object that gets added to the plots that when you drag it, the datagrid gets updated (by using dataGrid.ScrollIntoView). The code for the ScrollIntoView is in the xaml.cs file of the Datagrid.

To me this makes sense since the MainView has all the components and “sees” all the objects, so when the event handler of the dragWindow gets called, then the MainView asks for the DataGrid, and calls its method to update its column position. (This is the way I understand it, please feel free to correct me if I’m wrong).

Now I want to go the other way as well. So that if I update the scrollbar horizontally, then the dragwindow in the MainView will get updated. This does not make as much sense to me. I can create an event handler in the xaml.cs of the datagrid. But it does not see the dragWindow in the MainView right? So I’m not quite sure how to start implementing this functionality. Any help is always appreciated. Thanks!

Answer 1

Your grid control should expose an event to notify any consumers (MainView in this case) that scrolling has taken place.

public class YourGridControl
{
    public event EventHandler GridScrolled;
}

MainView can then attach a handler to this event in the designer or in the code:

gridCtrl.GridScrolled += OnGridScrolled;

private void OnGridScrolled(object sender, EventArgs e)
{
    // Logic here
}