Question

我正在开发一个简单的应用程序扫描QR码。要扫描QR码，我使用一种委托方法，如下所示。

- (void) imagePickerController: (UIImagePickerController*) reader didFinishPickingMediaWithInfo: (NSDictionary*) info

此外，我还有另一种源类型相机的委托方法来拍照。

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)img editingInfo:(NSDictionary *)editInfo

我有2个按钮用于扫描QR和拍照。但问题是当我拍摄新照片时

- (void) imagePickerController: (UIImagePickerController*) reader didFinishPickingMediaWithInfo: (NSDictionary*) info

调用

方法。怎么解决这个问题。当我选择照片按钮时，我需要调用特定的委托方法，当我打电话选择QR按钮时，我需要调用另一个委托方法。

Answer 1

首先 - 值得一提的是这个方法：

- (void)imagePickerController:(UIImagePickerController *)picker 
        didFinishPickingImage:(UIImage *)img 
                  editingInfo:(NSDictionary *)editInfo

自iOS 3.0起，

已弃用。现在使用的唯一方法是

- (void)imagePickerController:(UIImagePickerController *)picker  
didFinishPickingMediaWithInfo:(NSDictionary *)info

（从字典中获取图像参考）

要回答这个问题：您需要一种方法来识别委托回调中的每个picker。一种方法是创建几个属性，每个选择器一个属性，并在调用选择器时设置属性...

@property (nonatomic, weak) UIImagePickerController* QRpicker;
@property (nonatomic, weak) UIImagePickerController* cameraPicker;

创建您的QRPicker ......

 UIImagePickerController* QRpicker = [[UIImagePickerController alloc] init];
         //configure QRPicker
 [self presentViewController:QRpicker];
 self.QRpicker = QRpicker;

对cameraPicker执行相同的操作

然后你只需要检查哪种类型的选择器调用了委托方法

- (void)imagePickerController:(UIImagePickerController *)picker  
didFinishPickingMediaWithInfo:(NSDictionary *)info
{
  if ([picker isEqual:self.QRPicker])
      //code for QRPicker delegate
  else 
      //code for cameraPicker delegate

iPhone - 如何处理多个UIImagePickerControllerDelegate？

1 个答案: