ios - 蒙版图像并填充颜色

Question

我想用颜色遮盖 image 并填充选区和其余部分。我正在使用 CGImageCreateWithMaskingColors，但我不知道如何用另一种颜色填充 image。

这是我的代码的开始

UIImage *source = [UIImage imageNamed:@"nb.png"];

const CGFloat myMaskingColors[6] = {0,110,0,110,0,110};
CGImageRef imageRef = CGImageCreateWithMaskingColors(source.CGImage, myMaskingColors);
UIImage* imageB = [UIImage imageWithCGImage:imageRef];
UIImageView *imageView = [[UIImageView alloc]initWithImage:imageB];

感谢您的帮助编辑:我想我不清楚，我想选择一种颜色，其余选择另一种颜色

Answer 1

如果你想在图像上应用 2 种颜色，那么你可以像这样在图像上应用渐变

- (UIImage *)applyGradientOnImage:(UIImage *)image withStartColor:(UIColor *)color1 endColor:(UIColor *)color2 {
    UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, 0, image.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    CGContextSetBlendMode(context, kCGBlendModeNormal);
    CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
    //CGContextDrawImage(context, rect, img.CGImage);

    // Create gradient
    NSArray *colors = [NSArray arrayWithObjects:(id)color2.CGColor, (id)color1.CGColor, nil];
    CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
    CGGradientRef gradient = CGGradientCreateWithColors(space, (__bridge CFArrayRef)colors, NULL);

    // Apply gradient
    CGContextClipToMask(context, rect, image.CGImage);
    CGContextDrawLinearGradient(context, gradient, CGPointMake(0,0), CGPointMake(0, image.size.height), 0);
    UIImage *gradientImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    CGGradientRelease(gradient);
    CGColorSpaceRelease(space);

    return gradientImage;
}