C# Signature:

[DllImport("gdi32.dll")]
static extern bool DPtoLP(IntPtr hdc, [In, Out] POINT [] lpPoints, int nCount);

User-Defined Types:

POINT

Notes:

I cannot get this to work as-is. When I replace [In, Out] with [MarshalAs(UnmanagedType.LPArray)], everything is fine.

Tips & Tricks:

Please add some!

Sample Code:

POINT [] points = { new POINT(rect.Left, rect.Top), new POINT(rect.Right, rect.Bottom) };

bool ret = DPtoLP(m_hdc, points, 2);

Alternative Managed API:

Do you know one? Please contribute it!