RectangleF.Inflate Method (Single, Single)
Enlarges this RectangleF structure by the specified amount.
Assembly: System.Drawing (in System.Drawing.dll)
This method enlarges this rectangle, not a copy of it. The rectangle is enlarged in both directions along an axis. For example, if a 50 by 50 rectangle is inflated by 50 in the x-axis, the resultant rectangle will be 150 units long (the original 50, the 50 in the minus direction, and the 50 in the plus direction) maintaining the rectangle's geometric center.
If either x or y is negative, the RectangleF is deflated in the corresponding direction.
Available since 1.1