Get ListView items from other windows

I'm doing some project on c#. I need to get i item from ListView window, handle of it I got by doing something like this

IntPtr par_hWnd = API.FindWindow(null, "Form1");
IntPtr child1 = API.FindWindowEx(par_hWnd, (IntPtr)0, null, null);

API is my static class with lots of dllimports from "user32.dll" I am able to get count of items in this ListView:

IntPtr count = API.SendMessage(child1, API.LVM_GETITEMCOUNT, 0, 0);

Now i need to get the text of item, but the result somehow must be placed in the LVITEM Structure, I don't know how to call SendMessage correctly, and how to implement LVITEM in c#. Can't find examples for c#. Any help?