一、生成分享所需二维码

所需头文件

#import <CoreImage/CoreImage.h>

生成分享的二维码

    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [filter setDefaults];
    NSString *string = [NSString stringWithFormat:@"https://itunes.apple.com/cn/app/id%@",@"AppId"];
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    [filter setValue:data forKeyPath:@"inputMessage"];
    CIImage *image = [filter outputImage];

以上image就得到了所需二维码。不过这个二维码有点模糊，下面做高清处理。

二、图片高清处理

- (UIImage *)hdImageWithUIImage:(CIImage *)image width:(CGFloat)imageWidth {
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(imageWidth/CGRectGetWidth(extent), imageWidth/CGRectGetHeight(extent));
    size_t width = CGRectGetWidth(extent) * scale;
    size_t height = CGRectGetHeight(extent) * scale;
    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

三、二维码添加logo

以上得到了二维码，不过太单调了。我们在二维码的中间放上App的logo。

得到App的logo代码

    NSString *icon = [[[[NSBundle mainBundle] infoDictionary] valueForKeyPath:@"CFBundleIcons.CFBundlePrimaryIcon.CFBundleIconFiles"] lastObject];
    shareImageView.image = [UIImage imageNamed:icon];

以下是整套代码

    CGFloat imageWidth = AUTO_W(225);
    UIImageView *shareImageView = [[UIImageView alloc] init];
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [filter setDefaults];
    NSString *string = [NSString stringWithFormat:@"https://itunes.apple.com/cn/app/id%@",[VKLConfigParse parserConfig].AppId];
    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
    [filter setValue:data forKeyPath:@"inputMessage"];
    CIImage *image = [filter outputImage];
    UIImage *qrImage = [self hdImageWithUIImage:image width:imageWidth];
    NSString *icon = [[[[NSBundle mainBundle] infoDictionary] valueForKeyPath:@"CFBundleIcons.CFBundlePrimaryIcon.CFBundleIconFiles"] lastObject];
    UIImage *iconImage = [self hdImageWithUIImage:[UIImage imageNamed:icon].CIImage width:imageWidth * 0.3];
    UIGraphicsBeginImageContext(CGSizeMake(imageWidth, imageWidth));
    [qrImage drawInRect:CGRectMake(0, 0, imageWidth, imageWidth)];
    [iconImage drawInRect:CGRectMake((imageWidth - iconImage.size.width) * 0.5, (imageWidth - iconImage.size.height) * 0.5, iconImage.size.width, iconImage.size.height)];
    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    shareImageView.image = resultingImage;