在UIView上得到某一点的颜色值

- (UIColor *) colorOfPoint:(CGPoint)point

{

unsigned char pixel[4] = {0};

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

CGContextRef context = CGBitmapContextCreate(pixel, 1, 1, 8, 4, colorSpace, kCGImageAlphaPremultipliedLast);

CGContextTranslateCTM(context, -point.x, -point.y);

[self.layer renderInContext:context];

CGContextRelease(context);

CGColorSpaceRelease(colorSpace);

NSLog(@"pixel: %d %d %d %d", pixel[0], pixel[1], pixel[2], pixel[3]);

UIColor *color = [UIColor colorWithRed:pixel[0]/255.0 green:pixel[1]/255.0 blue:pixel[2]/255.0 alpha:pixel[3]/255.0];

return color;

}

在UIView上得到某一点的颜色值