X Window研究笔记(22)-简单示例

时间：2009-08-07 来源：lixianjing

X Window研究笔记(22)- 简单示例

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文章出处：http://www.limodev.cn/blog
作者联系方式：李先静 <xianjimli at hotmail dot com>

22.X Window 简单示例

对大多数linux程序员来说，很少有机会直接用Xlib去开发应用程序，那样开发效率太低，一般都是使用基于像GTK＋和QT这样的toolkit。不过了解一下XWindow编程没有什么坏处，这里举一个简单的例子，供新手参考：

xdemo.c

#include <string.h>
#include <X11/Xlib.h>
#include <X11/keysym.h>
 
int main(int argc, char* argv[])
 {
 Display* display = XOpenDisplay(NULL);
 int screen = DefaultScreen(display);
 int width = DisplayWidth(display, screen)/2;
 int height = DisplayHeight(display, screen)/2;
 
 Window win = XCreateSimpleWindow(display, RootWindow(display, screen),
 0, 0, width, height, 3, BlackPixel(display, screen), WhitePixel(display, screen));
 
 XSelectInput(display, win, ExposureMask|KeyPressMask | ButtonPressMask | StructureNotifyMask);
 
 GC gc = XCreateGC(display, win, 0, NULL);
 
 XMapWindow(display, win);
 
 while(1)
 {
 XEvent event = {0};
 XNextEvent(display, &event);
 switch(event.type)
 {
 case ConfigureNotify:
 {
 width = event.xconfigure.width;
 height = event.xconfigure.height;
 break;
 }
 case Expose:
 {
 XSetForeground(display, gc, WhitePixel(display, screen));
 XFillRectangle(display, win, gc, 0, 0, width, height);
 XSetForeground(display, gc, BlackPixel(display, screen));
 XDrawString(display, win, gc, width/2, height/2, "XWindow", 7);
 break;
 }
 case KeyPress:
 {
 if(event.xkey.keycode == XKeysymToKeycode(display, XK_Escape))
 {
 XFreeGC(display, gc);
 XCloseDisplay(display);
 return 0;
 }
 }
 default:break;
 }
 }
 
 return 0;
}
 
 Makefile
all:
 gcc -g -lX11 xdemo.c -o xdemo
clean:
 rm -f xdemo

（我并不擅长X Window编程，请不要问我关于X Window编程的问题。）