//二维码生成

    //UIImageView *theImageView = [[UIImageView alloc]init];

    //[self.view addSubview:theImageView];

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

    [filter setDefaults];

    NSData *data = [@"hello worold!" dataUsingEncoding:NSUTF8StringEncoding];

    [filter setValue:data forKey:@"inputMessage"];

    CIImage *outputImage = [filter outputImage];

    CIContext *context = [CIContext contextWithOptions:nil];

    CGImageRef cgImage = [context createCGImage:outputImage

                                       fromRect:[outputImage extent]];

    UIImage *image = [UIImage imageWithCGImage:cgImage

                                         scale:1.

                                   orientation:UIImageOrientationUp];

    NSLog(@"image QRCode : %@",NSStringFromCGSize(image.size));

    // Resize without interpolating

    UIImage *resized = [self resizeImage:image

                             withQuality:kCGInterpolationNone

                                    rate:5.0];

    NSLog(@"%@",NSStringFromCGSize(resized.size));

    UIImageView *theImageView =[[UIImageView alloc]initWithImage:resized];

    theImageView.frame = CGRectMake(100, 200, 100, 100);

    [self.view addSubview:theImageView];

    CGImageRelease(cgImage);

//Resize image

- (UIImage *)resizeImage:(UIImage *)image

             withQuality:(CGInterpolationQuality)quality

                    rate:(CGFloat)rate

{

	UIImage *resized = nil;

	CGFloat width = image.size.width * rate;

	CGFloat height = image.size.height * rate;

	UIGraphicsBeginImageContext(CGSizeMake(width, height));

	CGContextRef context = UIGraphicsGetCurrentContext();

	CGContextSetInterpolationQuality(context, quality);

	[image drawInRect:CGRectMake(0, 0, width, height)];

	resized = UIGraphicsGetImageFromCurrentImageContext();

	UIGraphicsEndImageContext();

	return resized;

}