在Objective c中将图像转换为字节

Question

 unsigned char *ImgBytes = [ImgBytes stringByAppendingString:getStringForImage:imageView.image];

错误Bad Receiver Type Unsigned char

Answer 1

NSString  *ImgBytes;
ImgBytes=[ImgBytes stringByAppendingString:[self getStringForImage:imageView.image]];

ImgBytes=[ImgBytes stringByAppendingString:[NSString stringWithFormat:@"^%@",q]];

-(NSString*)getStringForImage:(UIImage*)img
{
    @try {
        NSData *data = UIImagePNGRepresentation(img);
        NSUInteger len = data.length;
        uint8_t bytes = (uint8_t )[data bytes];
        NSMutableString *result = [NSMutableString stringWithCapacity:len];
        for (NSUInteger i = 0; i < len; i++) {
            if (i) {
                [result appendString:@","];
            }
            [result appendFormat:@"%d",bytes];
        }
        return result;
    } @catch (NSException * e) {
        NSLog(@"Exception: %@", e);
    }
    @finally {
        NSLog(@"finally");
    }
}