Topic 4. Working with graphics using Windows Forms and GDI+

Goal: become familiar with the GDI+ subsystem and the Windows Forms window repainting model; learn to draw shapes, text, and images with pens and brushes, use coordinate transformations, GraphicsPath outlines, and double buffering; master mouse handling, saving drawings as PNG, printing, and creating custom controls.

Lecture contents

1. The Paint event, colors, and pens — GDI+ and the Paint event · The coordinate system and colors · Pens, brushes, and releasing resources
2. Shapes, text, and transformations — Shapes · Text · Coordinate transformations · Compound shapes: GraphicsPath and Region
3. Animation and drawing with the mouse — Animation and double buffering · Interactive drawing with the mouse
4. Images, printing, and custom controls — Images, export, and printing · A custom control
5. Common mistakes — Common mistakes

Practice and review

• Practice — 3 worked examples with complete code
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links