将UIPinchGestureRecognizer添加到UIImagePickerController

Question

我试图将UIPinchGestureRecognizer添加到UIImagePickerController中以放大/缩小前面的摄像机，但无法调用UIPinchGestureRecognizer (handlePinchWithGestureRecognizer)中的方法。我没有收到任何错误，但也没有得到任何互动。

下面是我在viewDidAppear中使用的代码：

_imagePicker = [[UIImagePickerController alloc] init];
_imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
_imagePicker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
_imagePicker.allowsEditing = YES;
_imagePicker.showsCameraControls = NO;
_imagePicker.navigationBarHidden = YES;
_imagePicker.view.userInteractionEnabled = YES;
_imagePicker.view.multipleTouchEnabled = YES;
_imagePicker.delegate = self;

 UIPinchGestureRecognizer *pinchGestureRecognizer = pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchWithGestureRecognizer:)];


[_imagePicker.view addGestureRecognizer:pinchGestureRecognizer];

[self presentViewController:_imagePicker animated:NO completion:nil];

Answer 1

首先，我不会将手势识别器添加到UIKit视图控制器的视图中，这些视图不应该被子类化。你不知道里面到底发生了什么，你的识别器会如何干扰视图的标准功能。

其次，我试图在我的iPhone上放大前面的摄像头，这是不可能的。

如果您想从前面的摄像机获取视频并将其放大，您必须实现您自己的Controller，该控制器从前面的摄像机获取视频会话，并进行转换以进行缩放等等。