使用iOS-QR-Code-Encoder 生成二维码

一：所需类库

iOS-QR-Code-Encoder

　 官网主页：https://github.com/moqod/iOS-QR-Code-Encoder

导入：QuartzCore.framework

二：使用流程

1. 导入libqrencode文件夹里的所有文件
2. 在使用的地方 导入 

   #import "qrencode.h"

3. 添加如下生成代码：

//生成二维码：

- (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size {
    if (![string length]) {
        return nil;
    }

    // generate QR
    QRcode *code = QRcode_encodeString([string UTF8String], , QR_ECLEVEL_L, QR_MODE_8, );
    if (!code) {
        return nil;
    }

    if (code->width > size) {
        printf("Image size is less than qr code size (%d)\n", code->width);
        return nil;
    }

    // create context

    CGBitmapInfo bitmapInfo = (CGBitmapInfo) kCGImageAlphaPremultipliedLast;

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef ctx = CGBitmapContextCreate(, size, size, , size * , colorSpace, bitmapInfo);

    CGAffineTransform translateTransform = CGAffineTransformMakeTranslation(, -size);
    CGAffineTransform scaleTransform = CGAffineTransformMakeScale(, -);
    CGContextConcatCTM(ctx, CGAffineTransformConcat(translateTransform, scaleTransform));

    // draw QR on this context
    [self drawQRCode:code context:ctx size:size];

    // get image
    CGImageRef qrCGImage = CGBitmapContextCreateImage(ctx);
    UIImage * qrImage = [UIImage imageWithCGImage:qrCGImage];

    // free memory
    CGContextRelease(ctx);
    CGImageRelease(qrCGImage);
    CGColorSpaceRelease(colorSpace);
    QRcode_free(code);

    return qrImage;
}

- (void)drawQRCode:(QRcode *)code context:(CGContextRef)ctx size:(CGFloat)size {
    int margin = ;
    unsigned char *data = code->data;
    int width = code->width;
    int totalWidth = width + margin * ;
    int imageSize = (int)floorf(size);

    // @todo - review float->int stuff
    int pixelSize = imageSize / totalWidth;
    if (imageSize % totalWidth) {
        pixelSize = imageSize / width;
        margin = (imageSize - width * pixelSize) / ;
    }

    CGRect rectDraw = CGRectMake(0.0f, 0.0f, pixelSize, pixelSize);
    // draw
    CGContextSetFillColor(ctx, CGColorGetComponents([UIColor blackColor].CGColor));
    for(int i = ; i < width; ++i) {
        for(int j = ; j < width; ++j) {
            if(*data & ) {
                rectDraw.origin = CGPointMake(margin + j * pixelSize, margin + i * pixelSize);
                CGContextAddRect(ctx, rectDraw);
            }
            ++data;
        }
    }
    CGContextFillPath(ctx);
}

三：调用生成二维：

        //数据处理部分
        CGFloat qrcodeLength = ;
        UIImageView *imageV = [[UIImageView alloc]initWithFrame:CGRectMake((contentView.width-qrcodeLength)/, , qrcodeLength,qrcodeLength)];
        //imageV.backgroundColor = [UIColor grayColor];
        //添加二维码
        imageV.image = [self qrImageForString:@"2013.11.11购物狂欢节" imageSize:qrcodeLength];
        [contentView addSubview:imageV];