从 Objective-C 中的像素获取颜色

Question

我想从屏幕上的坐标中获取颜色并将其放入变量中。我正在使用 Theos，只是为了学习而在我的 iOS 5 设备上闲逛，所以请不要像我在所有帖子中看到的那样启动 "stop wasting your time making tweaks for old iOS" :|

Answer 1

试试下面的代码：

// 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, kCGBitmapAlphaInfoMask & 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;
}

您可以在此处找到文件：https://github.com/ivanzoid/ikit/tree/master/UIView%2BColorOfPoint

此外，请在此处查看答案以获取更多信息：How to get the color of a pixel in an UIView?

从 Objective-C 中的像素获取颜色

Get color from pixel in Objective-C

objective-c

jailbreak

ios

theos