xlib编程-一个简单的xlib程序

 

/*
* Simple Xlib application drawing a box in a window.
*/

#include <X11/Xlib.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
        struct _XDisplay *d;
        int s;
        Window w;
        XEvent e;

        /* To open a connection to the X server that controls a display*/
        d = XOpenDisplay(NULL);
        if(d == NULL)
        {
                printf("Cannot open display\n");
                exit(1);
        }

/* Both return the default screen number referenced by the XOpenDisplay() function */
        s = DefaultScreen(d);

        /* create window */
        w = XCreateSimpleWindow(d,
                                RootWindow(d, s),
                                10,
                                10,
                                100,
                                100,
                                1,
                                BlackPixel(d, s),
                                WhitePixel(d, s));

        /* select kind of events we are interested in */
        XSelectInput(d, w, ExposureMask | KeyPressMask);

        /* map (show) the window */
        XMapWindow(d, w);

        /* event loop */
        while(1)
        {
                XNextEvent(d, &e);
                /* draw or redraw the window */
                if(e.type == Expose)
                {
                        XFillRectangle(d, w, DefaultGC(d, s), 10, 10, 100, 100);
                }
                /* exit on key press */
                if(e.type == KeyPress)
                        break;
        }

        /* close connection to server */
        XCloseDisplay(d);

        return 0;
}