X Window研究笔记(22)-简单示例

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

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 
#include 
#include 
 
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。）