Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

Drawing with GDI+

Previous lessons have touched upon drawing graphics in a couple of places. For example,

Lesson 23 uses a

Turtle class that provides drawing methods, and Lesson 31 explains

printing, which requires that you draw text, lines, and whatever other shapes you want

to print.

However, I’ve mostly avoided discussing graphics code. While I find graphics code a lot of

fun, I have to admit that it’s usually not a high priority for most business applications (aside

from printing).

This lesson explains the basics of graphics programming in C#. It explains the objects that

you use to produce graphics and shows how to use those objects to draw on bitmaps or con-

trols at run time.

Before you can start drawing bar charts or building a new painting application, however, you

need to know about three classes:

Graphics, Pen, and Brush.

GRAPHICS

The Graphics class represents the drawing surface, whether it is a bitmap stored in memory,

a control’s surface on the screen, or a printed page (you saw printing in Lesson 31). In many

ways you can think of

Graphics as the “paper” on which you’re drawing.

The

Graphics class provides the methods that do the actual drawing. Many of them come in

two flavors: one for drawing and one for filling. For example,

DrawRectangle draws a hollow

rectangle and

FillRectangle fills in a rectangle’s interior.

Table 39-1 summarizes some of the most useful of those metho ...