一、下載地址

下載：https://github.com/puyangdev/PYColorPicker

二、 效果

三、關鍵程式碼

//獲取圖片某一點的顏色
- (UIColor *)colorAtPixel:(CGPoint)point {
    if (!CGRectContainsPoint(CGRectMake(0.0f, 0.0f, self.image.size.width, self.image.size.height), point)) {
        return nil;
    }
    
    NSInteger pointX = trunc(point.x);
    NSInteger pointY = trunc(point.y);
    CGImageRef cgImage = self.image.CGImage;
    NSUInteger width = self.image.size.width;
    NSUInteger height = self.image.size.height;
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    int bytesPerPixel = 4;
    int bytesPerRow = bytesPerPixel * 1;
    NSUInteger bitsPerComponent = 8;
    unsigned char pixelData[4] = { 0, 0, 0, 0 };
    CGContextRef context = CGBitmapContextCreate(pixelData,
                                                 1,
                                                 1,
                                                 bitsPerComponent,
                                                 bytesPerRow,
                                                 colorSpace,
                                                 kCGImageAlphaPremultipliedLast |     kCGBitmapByteOrder32Big);
    CGColorSpaceRelease(colorSpace);
    CGContextSetBlendMode(context, kCGBlendModeCopy);
    
    CGContextTranslateCTM(context, -pointX, pointY-(CGFloat)height);
    CGContextDrawImage(context, CGRectMake(0.0f, 0.0f, (CGFloat)width, (CGFloat)height), cgImage);
    CGContextRelease(context);
    
    CGFloat red   = (CGFloat)pixelData[0] / 255.0f;
    CGFloat green = (CGFloat)pixelData[1] / 255.0f;
    CGFloat blue  = (CGFloat)pixelData[2] / 255.0f;
    CGFloat alpha = (CGFloat)pixelData[3] / 255.0f;
    NSLog(@"%f %f %f %f",(CGFloat)pixelData[0],(CGFloat)pixelData[1],(CGFloat)pixelData[2],(CGFloat)pixelData[3]);
    return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
}