根据坐标过去颜色
- (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; }