在UIImage中将某些颜色更改为透明

Question

i have color 255.0.180 and i need to convert this color to transparent. When i use white color, this code works fine:

     image = UIImage(data: UIImageJPEGRepresentation(image, 1.0)!)!

    let rawImageRef: CGImageRef = image.CGImage!

    let colorMasking: [CGFloat] = [222, 255, 222, 255, 222, 255]
    //        222.0/255.0, 255.0/255.0,
    UIGraphicsBeginImageContext(image.size);
    let maskedImageRef=CGImageCreateWithMaskingColors(rawImageRef, colorMasking);


    CGContextTranslateCTM(UIGraphicsGetCurrentContext(), 0.0, image.size.height);
    CGContextScaleCTM(UIGraphicsGetCurrentContext(), 1.0, -1.0);


    CGContextDrawImage(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, image.size.width, image.size.height), maskedImageRef);
    let result = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return  result!

when i use same code with colorMasking: 222, 255, 222, 0, 255, 180 - doesn't work. Can you help me, please?

Answer 1

也许如果您愿意，可以只调用此UIColor.clearColor（），这将为您提供透明的颜色。