处理captureStillImageAsynchronouslyFromConnection：completionHandler：

Question

我一直在试图设置一个小的iOS方法，当用户打开应用程序时自动拍照。经过大量的研究，我终于找到了这个iOS taking photo programmatically，并且在我从苹果中发现了这个之后，我再次发现了这个https://developer.apple.com/library/ios/samplecode/AVCam/Introduction/Intro.html有人可以帮我开始设置一个方法captureStillImageAsynchronouslyFromConnection:completionHandler: 我不希望来自这个用户的任何交互。感谢

Answer 1

即使你似乎想要做的异步调用，并使用AVFoundation，我还是在这种情况下，建议只需使用UIImagePickerController，例如：

- (void)viewDidLoad { 

    [super viewDidLoad]; 

    // If the device has a camera... 
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) { 

     // Create an image picker 
     UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init]; 
     imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera; 
     imagePickerController.cameraDevice = UIImagePickerControllerCameraDeviceFront; 
     imagePickerController.showsCameraControls = NO; 
     imagePickerController.delegate = self; 

     [self presentViewController:imagePickerController animated:YES completion:^{ 

      // And take the picture after a short delay 
      // to give the view and image picker time to get 
      // ready 
      [self performSelector:@selector(takepic:) withObject:imagePickerController afterDelay:2]; 
     }]; 
    } 
} 

// Automatically take the picture using the 
// image picker passed in as a parameter 
- (void)takepic:(UIImagePickerController*)imagePickerController { 
    [imagePickerController takePicture]; 
} 

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { 
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage]; 

    // ... Do whatever with the image ... 

    [picker dismissViewControllerAnimated:YES completion:nil]; 
}