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], 0, QR_ECLEVEL_L, QR_MODE_8, 1);
    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(0, size, size, 8, size * 4, colorSpace, bitmapInfo);
    
    CGAffineTransform translateTransform = CGAffineTransformMakeTranslation(0, -size);
    CGAffineTransform scaleTransform = CGAffineTransformMakeScale(1, -1);
    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 = 0;
    unsigned char *data = code->data;
    int width = code->width;
    int totalWidth = width + margin * 2;
    int imageSize = (int)floorf(size);
    
    // @todo - review float->int stuff
    int pixelSize = imageSize / totalWidth;
    if (imageSize % totalWidth) {
        pixelSize = imageSize / width;
        margin = (imageSize - width * pixelSize) / 2;
    }
    
    CGRect rectDraw = CGRectMake(0.0f, 0.0f, pixelSize, pixelSize);
    // draw
    CGContextSetFillColor(ctx, CGColorGetComponents([UIColor blackColor].CGColor));
    for(int i = 0; i < width; ++i) {
        for(int j = 0; j < width; ++j) {
            if(*data & 1) {
                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 = 150;
        UIImageView *imageV = [[UIImageView alloc]initWithFrame:CGRectMake((contentView.width-qrcodeLength)/2, 10, 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];