Research about applications 3_RA

In graphical user interfaces such as Microsoft Windows, drawing on the screen is an important task.

Everything displayed on the screen is based on simple drawing operations. In Visual Studio .NET, developers have easy access to that drawing functionality whenever they need it through a technology called GDI+. Using GDI+, developers can easily perform drawing operations such as generating graphs or building custom controls.

All GDI+ drawing is done using a Graphics object. This object has a large number of methods that encapsulate drawing operations on a drawing “canvas.” GDI+ supports some drawing canvases including windows, bitmaps, and printer pages. Depending on the type of drawing canvas, the Graphics object is created or retrieved in several different ways. If you want to modify the contents of a bitmap file you would create a Bitmap canvas using the FromImage() method.

Drawing in a WinForms form is a somewhat peculiar task because it is not enough to draw the graphic once. Instead, the “drawing” may have to be “refreshed” (re-drawn) whenever a window requires repainting. Repainting can happen whenever a user resizes a window or one window overlaps another window and then something brings the overlapped windows to the front.

Whenever you use GDI+ to draw, you use the GDI+ coordinate system. By default, the coordinate system maps directly to the pixels on your monitor. However, you may want different behaviour. You can transform the coordinate system if you have special needs.

Graphics class’s methods:

Graphics class’s properties:

References

The Basics of GDI (codemag.com)

GDI+ Tutorial for Beginners (c-sharpcorner.com)

Graphics Class (System.Drawing) | Microsoft Docs