iOS遇到的坑

1、二维码尺寸必须是59*59及以上，否则微信内长按识别不了二维码，其他手机扫二维码可能会扫不出来

代码:

+ (UIImage *)generateQRCodeWithString:(NSString *)string size:(CGFloat)size {

    if(!string || string.length==0) {

        returnUIImage.new;

    }

    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

    //过滤器恢复默认

    [filtersetDefaults];

    //给过滤器添加数据<字符串长度893>

    NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion: NO];

    [filtersetValue:dataforKey:@"inputMessage"];

    // 注： 这里如果设置H的时间 二维码太小可能会造成信息不全 无法扫描

    [filtersetValue:@"M" forKey:@"inputCorrectionLevel"];

    //获取二维码过滤器生成二维码

    CIImage*image = [filteroutputImage];

    UIImage *img = [self createNonInterpolatedUIImageFromCIImage:[image imageByApplyingTransform:CGAffineTransformMakeScale(YYScreenScale(), YYScreenScale())] WithSize:size];

    returnimg;

}

+ (UIImage *)createNonInterpolatedUIImageFromCIImage:(CIImage *)image WithSize:(CGFloat)size {

    CGRect extent = CGRectIntegral(image.extent);

    CGFloatscale =MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

    //创建bitmap

    size_twidth =CGRectGetWidth(extent)*scale;

    size_theight =CGRectGetHeight(extent)*scale;

    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRefbitmapImage = [contextcreateCGImage:imagefromRect:extent];

    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);

    CGContextScaleCTM(bitmapRef, scale, scale);

    CGContextDrawImage(bitmapRef, extent, bitmapImage);

    //保存图片

    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

//    UIImage *newImage = [UIImage imageWithCGImage:scaledImage];

    UIImage *newImage = [UIImage imageWithCGImage:scaledImage scale:YYScreenScale() orientation:UIImageOrientationUp];

    CGContextRelease(bitmapRef);

    CGImageRelease(bitmapImage);

    CGColorSpaceRelease(cs);

    CGImageRelease(scaledImage);

    returnnewImage;

}