uiview 某点返回 色值 How to get the color of a pixel in an UIView?

// UIView+ColorOfPoint.h
@interface UIView (ColorOfPoint)
- (UIColor *) colorOfPoint:(CGPoint)point;
@end

// UIView+ColorOfPoint.m
#import "UIView+ColorOfPoint.h"
#import <QuartzCore/QuartzCore.h>

@implementation UIView (ColorOfPoint)

- (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;
}

@end

Link to files:https://github.com/ivanzoid/ikit/tree/master/UIView+ColorOfPoint