GDI is an acronym for Graphics Device Interface, the main task is responsible for the exchange of information between the system and drawing program, deal with graphics and image output all Windows programs. The emergence of GDI programmers no need to worry about hardware and equipment normal driving, it is the application's output and the output can be converted to constitute the hardware to achieve the isolation program developers and hardware, greatly facilitate the development work.
Chinese name of the Graphics Device Interface
English name GDI (Graphics Device Interface)
Information exchange system and is responsible for the task of drawing programs
Features facilitate the development work
basic introduction
GDI is an acronym for Graphics Device Interface, the meaning is the Graphics Device Interface , its main task is responsible for the exchange of information between the system and drawing program, deal with the graphical output of all Windows programs.
In the Windows operating system, the vast majority of applications with graphical interfaces are inseparable from the GDI, we use a number of GDI function can be easily provided in the screen, the output operation graphics, text, and so on printers and other output devices.
Feature
GDI has the following characteristics:
1. The program does not allow direct access to physical hardware displays, through a process called "device context" of the abstract interface indirect access to the display hardware;
2. When the program needs to communicate with the display hardware (display, printer, etc.), you must first obtain a device context associated with a particular window;
3. The user without concern for the specific type of physical device;
4. Windows environment data structure of the reference device output data is completed.
GDI functions generally can be classified as:
Device context function (e.g. GetDC, CreateDC, DeleteDC), line drawing function (e.g., LineTo, Polyline, Arc), filling drawing function (e.g., Ellipse, FillRect, Pie), drawing property function (e.g. SetBkColor, SetBkMode, SetTextColor), text, Font function (e.g. TextOut, GetFontData), bitmap function (e.g. SetPixel, BitBlt, StretchBlt), the coordinates of the function (e.g. DPtoLP, LPtoDP, ScreenToClient, ClientToScreen), the mapping function (e.g. SetMapMode, SetWindowExtEx, SetViewportExtEx), metafile functions (e.g. PlayMetaFile, SetWinMetaFileBits), function region (e.g. FillRgn, FrameRgn, InvertRgn), path function (e.g. BeginPath, EndPath, StrokeAndFillPath), clipping function (e.g. SelectClipRgn, SelectClipPath) and the like.