头文件graphics.h包含getpixel()函数，该函数返回位置(x，y)处像素的颜色。
用法:
int getpixel(int x, int y);
注意：默认情况下，屏幕为黑色，因此(0,0)处像素的颜色为黑色。
下面是getpixel()函数的实现。
// C Implementation for getpixel()
#include
#include
// driver code
int main()
{
// gm is Graphics mode which is
// a computer display mode that
// generates image using pixels.
// DETECT is a macro defined in
// "graphics.h" header file
int gd = DETECT, gm, color;
char arr[50];
// initgraph initializes the
// graphics system by loading a
// graphics driver from disk
initgraph(&gd, &gm, "");
// getpixel function
color = getpixel(0, 0);
// sprintf stands for “String print”.
// Instead of printing on console,
// it store output on char buffer
// which are specified in sprintf
sprintf(arr, "color of pixel at (0,0) = %d",
color);
// outtext function displays text
// at current position.
outtext(arr);
getch();
// closegraph function closes the
// graphics mode and deallocates
// all memory allocated by
// graphics system .
closegraph();
return 0;
}
输出：
说明：由于屏幕上未画任何东西，并且默认情况下屏幕为黑色，因此(0，0)处像素的颜色为黑色，因为0表示黑色。
