生成二维码
#import "ViewController.h" #import <CoreImage/CoreImage.h> @interface ViewController () @property (weak, nonatomic) IBOutlet UIImageView *imageView; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; } - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { // 1.创建过滤器 CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; // 2.恢复默认 [filter setDefaults]; // 3.给过滤器添加数据(正则表达式/账号和密码) NSString *dataString = @"http://www.520it.com"; NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding]; [filter setValue:data forKeyPath:@"inputMessage"]; // 4.获取输出的二维码 CIImage *outputImage = [filter outputImage]; // 5.显示二维码 self.imageView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200]; } /** * 根据CIImage生成指定大小的UIImage * * @param image CIImage * @param size 图片宽度 */ - (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size { CGRect extent = CGRectIntegral(image.extent); CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent)); // 1.创建bitmap; 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); // 2.保存bitmap到图片 CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef); CGContextRelease(bitmapRef); CGImageRelease(bitmapImage); return [UIImage imageWithCGImage:scaledImage]; } @end