系统原生方法 生成二维码

1.可以直接返回二维码图片 UIimage

pragma mark-> 二维码生成

1、-(UIImage *)createQRimageWithStr:(NSString *)str
{
    UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:[self createQRForString:str] withSize:250.0f];
    UIImage *customQrcode = [self imageBlackToTransparent:qrcode withRed:0.0f andGreen:0.0f andBlue:0.0f];
    return customQrcode;
}

2.或者返回二维码UIImageView 还可以设置shadow样式

1、-(UIImageView *)getQRCodeImageViewWithStr:(NSString *)codeUrl
{
    UIImage *qrcode = [self createNonInterpolatedUIImageFormCIImage:[self createQRForString:codeUrl] withSize:250.0f];
    UIImage *customQrcode = [self imageBlackToTransparent:qrcode withRed:0.0f andGreen:0.0f andBlue:0.0f];
    UIImageView *_qrImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, SF(150), SF(150))];
    _qrImageView.image = customQrcode;
    // set shadow
    _qrImageView.layer.shadowOffset = CGSizeMake(0, 2);
    _qrImageView.layer.shadowRadius = 2;
    _qrImageView.layer.shadowColor = [UIColor blackColor].CGColor;
    _qrImageView.layer.shadowOpacity = 0.5;
    return _qrImageView;
}

具体实现方法

pragma mark - InterpolatedUIImage

- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/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);
    // release
    CGColorSpaceRelease(cs);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

pragma mark - QRCodeGenerator

- (CIImage *)createQRForString:(NSString *)qrString {
    NSData *stringData = [qrString dataUsingEncoding:NSUTF8StringEncoding];
    
    CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    [qrFilter setValue:stringData forKey:@"inputMessage"];
    [qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"];
    return qrFilter.outputImage;
}

pragma mark - imageToTransparent

void ProviderReleaseData (void *info, const void *data, size_t size){
    free((void*)data);
}

改变二维码颜色

- (UIImage*)imageBlackToTransparent:(UIImage*)image withRed:(CGFloat)red andGreen:(CGFloat)green andBlue:(CGFloat)blue{
    const int imageWidth = image.size.width;
    const int imageHeight = image.size.height;
    size_t      bytesPerRow = imageWidth * 4;
    uint32_t* rgbImageBuf = (uint32_t*)malloc(bytesPerRow * imageHeight);
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbImageBuf, imageWidth, imageHeight, 8, bytesPerRow, colorSpace,kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    CGContextDrawImage(context, CGRectMake(0, 0, imageWidth, imageHeight), image.CGImage);
    int pixelNum = imageWidth * imageHeight;
    uint32_t* pCurPtr = rgbImageBuf;
    for (int i = 0; i < pixelNum; i++, pCurPtr++){
if ((*pCurPtr & 0xFFFFFF00) < 0x99999900){
// change color
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[3] = red; //0~255
ptr[2] = green;
ptr[1] = blue;
}else{
uint8_t* ptr = (uint8_t*)pCurPtr;
ptr[0] = 0;
}
    }
    
    CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgbImageBuf, bytesPerRow * imageHeight, ProviderReleaseData);
    CGImageRef imageRef = CGImageCreate(imageWidth, imageHeight, 8, 32, bytesPerRow, colorSpace,
kCGImageAlphaLast | kCGBitmapByteOrder32Little, dataProvider,
NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease(dataProvider);
    UIImage* resultUIImage = [UIImage imageWithCGImage:imageRef];
    // release
    CGImageRelease(imageRef);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    return resultUIImage;
}”