/// 开始扫描二维码  - (IBAction)clickStart:(id)sender {      WHC_QRCodeVC * vc = [WHC_QRCodeVC new];      /// 扫描二维码代理      vc.delegate = self;      /// 生成二维码图片地址      vc.myQRCodeUrl = @"https://github.com/netyouli?tab=repositories";      [self presentViewController:vc animated:YES completion:nil];  }    #pragma mark - WHC_QRCodeVCDelegate  /// 扫描二维码回调  - (void)WHCQRCodeVCScanCallBack:(NSString *)value isQRCode:(BOOL)isQRCode {      if (isQRCode) {          QRCodeWebVC * vc = [QRCodeWebVC new];          vc.value = value;          [self presentViewController:vc animated:YES completion:nil];      }else {          [[[UIAlertView alloc] initWithTitle:value                                      message:nil                                      delegate:nil                                      cancelButtonTitle:@"OK"                                      otherButtonTitles:nil,                                      nil] show];      }  }    /// 生成二维码图片回调  - (void)WHCQRCodeVCBecomeQRCodeImage:(UIImage *)image {      MyQRCodeVC * vc = [MyQRCodeVC new];      vc.myQRCodeImage = image;      [self presentViewController:vc animated:YES completion:nil];  }