Getting mouse position in c#

If you need to get current position in form's area (got experimentally), try the following:

Console.WriteLine(
    "Current mouse position in form's area is " + 
    (Control.MousePosition.X - this.Location.X - 8).ToString() +
    "x" + 
    (Control.MousePosition.Y - this.Location.Y - 30).ToString()
);

Although, 8 and 30 integers were found while experimenting. It'd be awesome if someone could explain why exactly these numbers worked.

Also, there's another variant (considering code is in a form's code-behind):

Point cp = PointToClient(Cursor.Position); // Get cursor's position according to form's area
Console.WriteLine("Cursor position: X = " + cp.X + ", Y = " + cp.Y);

   internal static class CursorPosition {
  [StructLayout(LayoutKind.Sequential)]
  public struct PointInter {
     public int X;
     public int Y;
     public static explicit operator Point(PointInter point) => new Point(point.X, point.Y);       
  }

  [DllImport("user32.dll")]
  public static extern bool GetCursorPos(out PointInter lpPoint);

  // For your convenience
  public static Point GetCursorPosition() {
     PointInter lpPoint;
     GetCursorPos(out lpPoint);
     return (Point) lpPoint;
  }

}

This answer was not eligible at the time the question was asked, but today you can use the static method Mouse.GetPosition(IInputElement) from the namespace System.Windows.Input in the PresentationCore assembly. This is valid from .NET Framework 3.0 and forward. Find more information on https://docs.microsoft.com/en-us/dotnet/api/system.windows.input.mouse.getposition?view=windowsdesktop-6.0#System_Windows_Input_Mouse_GetPosition_System_Windows_IInputElement_

Example:

// displayArea is a StackPanel and txtBoxMousePosition is
// a TextBox used to display the position of the mouse pointer.
Point position = Mouse.GetPosition(displayArea);
txtBoxMousePosition.Text = "X: " + position.X +
    "\n" +
    "Y: " + position.Y;