AutomationElement child = walker.GetFirstChild(el);
using windows automation How do i simulator a left single click on Child ?
try with:
AutomationElement child = walker.GetFirstChild(el);
System.Windows.Point p = child.GetClickablePoint();
Mouse.Move((int)p.X, (int)p.Y);
Mouse.Click(MouseButton.Left);
Links:
AutomationElement.GetClickablePoint Method
Simulate mouse Enter/Move/Leave on WPF control without real mouse usage
Edit for comment
See this links:
Mouse.cs
NativeMethods.cs
Introduction to TestApi – Part 1: Input Injection APIs