iOS，UIImagePickerController有没有一种方法来检测用户点击拍照button，而不实现自定义控件？
Xcode 7.3，iOS 9.3.1
我想为用户即将拍摄照片和编辑照片之后使用两个自定义叠加视图。 要改变覆盖，我想知道是否有一个从UIImagePickerControllerDelegate的callback方法，让我知道当用户开始编辑图片，或者当用户点击拍照button。
我所知道的唯一方法是：
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info - (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
我已经看了这里： UIImagePickerController与cameraOverlayView的重点，当button叠加被点击 ， 如何知道我点击“拍照button”与UIImagePicker和iOS – 拍照后button在UIImagePickerController CustomOverlayView点击 。
或者也许有一种方法可以通过添加观察者来从标准button中获取点击事件。
请帮忙！ 提前致谢。
您可以使用在使用UIImagePickerController时也必须实现的UINavigationControllerDelegate 。 像这样实现委托方法[...]didShowViewController[...]
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated { NSLog(@"%@", [viewController class]); }
产生以下输出（使用模拟器，selectUIImagePickerControllerSourceTypePhotoLibrary作为sourceType并像这样浏览：相册概述>特定相册>编辑特定照片）：
2016-04-08 00：19：36.882 ImagePicker [44578：4705834] PUUIAlbumListViewController
2016-04-08 00：19：41.341 ImagePicker [44578：4705834] PUUIMomentsGridViewController
2016-04-08 00：19：47.929 ImagePicker [44578：4705834] PUUIImageViewController
希望有所帮助！
UIImagePickerControllerDelegate是相当差，但你可以通过添加一个观察者来处理它：
Swift 3：
NotificationCenter.default.addObserver(forName: NSNotification.Name(rawValue: "_UIImagePickerControllerUserDidCaptureItem"), object:nil, queue:nil, using: { note in //Do something })
Objective-C的：
[[NSNotificationCenter defaultCenter] addObserverForName:@"_UIImagePickerControllerUserDidCaptureItem" object:nil queue:nil usingBlock:^(NSNotification * _Nonnull note) { //Do something }];
Xcode 8.2.1，iOS10.2.1
在实施之前，请阅读早期版本的解决scheme以了解基础知识。 谢谢！ 问题是，各种子视图的一些名称已经从iOS 9.3.1更改为iOS 10.2.1。
这里是完整的代码（见下面插入位置），代替“//代码在这里”：
for (UIView *subviewImagePickerControllerView in self.imagePickerController.view.subviews) { if ([subviewImagePickerControllerView.class.description isEqualToString:@"UINavigationTransitionView"]) { for (UIView *subviewUINavigationTransitionView in subviewImagePickerControllerView.subviews) { if ([subviewUINavigationTransitionView.class.description isEqualToString:@"UIViewControllerWrapperView"]) { for (UIView *subviewUIViewControllerWrapperView in subviewUINavigationTransitionView.subviews) { if ([subviewUIViewControllerWrapperView.class.description isEqualToString:@"CAMCameraViewControllerContainerView"]) { for (UIView *subviewCAMCameraViewControllerContainerView in subviewUIViewControllerWrapperView.subviews) { if ([subviewCAMCameraViewControllerContainerView.class.description isEqualToString:@"CAMViewfinderView"]) { for (UIView *subviewCAMViewfinderView in subviewCAMCameraViewControllerContainerView.subviews) { if ([subviewCAMViewfinderView.class.description isEqualToString:@"CAMBottomBar"]) { for (UIView *subviewCAMBottomBar in subviewCAMViewfinderView.subviews) { if ([subviewCAMBottomBar.class.description isEqualToString:@"CUShutterButton"] && [subviewCAMBottomBar.class isSubclassOfClass:[UIButton class]]) { UIButton *shutterButton = (UIButton *)subviewCAMBottomBar; [shutterButton addTarget:self action:@selector(touchUpInsideCMKShutterButton) forControlEvents:UIControlEventTouchUpInside]; } else { nil; } } } } } else if ([subviewCAMCameraViewControllerContainerView.class.description isEqualToString:@"PLCropOverlay"]) { for (UIView *subviewPLCropOverlay in subviewCAMCameraViewControllerContainerView.subviews) { if ([subviewPLCropOverlay.class.description isEqualToString:@"PLCropOverlayBottomBar"]) { for (UIView *subviewPLCropOverlayBottomBar in subviewPLCropOverlay.subviews) { if ([subviewPLCropOverlayBottomBar.class.description isEqualToString:@"PLCropOverlayPreviewBottomBar"]) { for (UIView *itemPLCropOverlayPreviewBottomBar in subviewPLCropOverlayBottomBar.subviews) { if ([itemPLCropOverlayPreviewBottomBar.class isSubclassOfClass:[UIButton class]]) { UIButton *buttonPLCropOverlay = (UIButton *)itemPLCropOverlayPreviewBottomBar; if ([buttonPLCropOverlay.titleLabel.text isEqualToString:@"Retake"]) { UIButton *retakeButton = buttonPLCropOverlay; [retakeButton addTarget:self action:@selector(touchUpInsideButtonRetake) forControlEvents:UIControlEventTouchUpInside]; } else { nil; } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } }
Xcode 7.3，iOS9.3.1
我必须得到这个工作，所以我花了很多时间搞清楚这一点。
其要点在于，在UIImagePickerController出现之后，向下钻取视图层次结构，查找CMKShutterButton和带有“Retake”标题的重拍button，然后将select器附加到button的动作，就像这样…
[shutterButton addTarget:self action:@selector(touchUpInsideCMKShutterButton) forControlEvents:UIControlEventTouchUpInside]; [retakeButton addTarget:self action:@selector(touchUpInsideButtonRetake) forControlEvents:UIControlEventTouchUpInside];
将下面的代码放到您的图像select器出现后调用的完成块中：
[self presentViewController:self.imagePickerController animated:true completion:^(void){ //Code goes here }
这里是完整的代码，代替了上面的代码：
for (UIView *subviewImagePickerControllerView in self.imagePickerController.view.subviews) { if ([subviewImagePickerControllerView.class.description isEqualToString:@"UINavigationTransitionView"]) { for (UIView *subviewUINavigationTransitionView in subviewImagePickerControllerView.subviews) { if ([subviewUINavigationTransitionView.class.description isEqualToString:@"UIViewControllerWrapperView"]) { for (UIView *subviewUIViewControllerWrapperView in subviewUINavigationTransitionView.subviews) { if ([subviewUIViewControllerWrapperView.class.description isEqualToString:@"PLImagePickerCameraView"]) { for (UIView *subviewPLImagePickerCameraView in subviewUIViewControllerWrapperView.subviews) { if ([subviewPLImagePickerCameraView.class.description isEqualToString:@"CMKBottomBar"]) { for (UIView *itemCMKBottomBar in subviewPLImagePickerCameraView.subviews) { if ([itemCMKBottomBar.class.description isEqualToString:@"CMKShutterButton"] && [itemCMKBottomBar.class isSubclassOfClass:[UIButton class]]) { UIButton *shutterButton = (UIButton *)itemCMKBottomBar; [shutterButton addTarget:self action:@selector(touchUpInsideCMKShutterButton) forControlEvents:UIControlEventTouchUpInside]; } else { nil; } } } else if ([subviewPLImagePickerCameraView.class.description isEqualToString:@"PLCropOverlay"]) { for (UIView *subviewPLCropOverlay in subviewPLImagePickerCameraView.subviews) { if ([subviewPLCropOverlay.class.description isEqualToString:@"PLCropOverlayBottomBar"]) { for (UIView *subviewPLCropOverlayBottomBar in subviewPLCropOverlay.subviews) { if ([subviewPLCropOverlayBottomBar.class.description isEqualToString:@"PLCropOverlayPreviewBottomBar"]) { for (UIView *itemPLCropOverlayPreviewBottomBar in subviewPLCropOverlayBottomBar.subviews) { if ([itemPLCropOverlayPreviewBottomBar.class isSubclassOfClass:[UIButton class]]) { UIButton *buttonPLCropOverlay = (UIButton *)itemPLCropOverlayPreviewBottomBar; if ([buttonPLCropOverlay.titleLabel.text isEqualToString:@"Retake"]) { UIButton *retakeButton = buttonPLCropOverlay; [retakeButton addTarget:self action:@selector(touchUpInsideButtonRetake) forControlEvents:UIControlEventTouchUpInside]; } else { nil; } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } } } else { nil; } }
这里是我附加的方法，它在呈现图像select器控制器的视图控制器中进行：
- (void)touchUpInsideCMKShutterButton { NSLog(@"Take"); } - (void)touchUpInsideButtonRetake { NSLog(@"Re-take"); }
希望这可以帮助别人！ 谢谢。