Question

自iOS 10推出以来，我们几年前开发的应用程序已经开始崩溃。该应用程序重复呈现UIImagePickerControllers，以允许用户捕获主题的多张照片。这样做了40多次后，应用程序崩溃了。这在我们测试过的所有设备上都是可重现的，但在引入iOS 10之前没有发生。我们在Info.plist文件中有NSCameraUsageDescription和NSPhotoLibraryUsageDescription键。

我创建了一个演示问题的最小示例应用。这是最终导致崩溃的代码：

- (IBAction) cameraPressed:(id) sender {
    self.picker = [[UIImagePickerController alloc] init];
    self.picker.sourceType =  UIImagePickerControllerSourceTypeCamera;
    self.picker.delegate = self;
    self.picker.allowsEditing = NO;
    [self presentViewController:self.picker animated:YES completion:nil];
}

当用户反复使用连接到此IBAction的相机按钮时，它最终开始变慢（拾取器的呈现开始花费更长时间），并最终崩溃（通常在使用相机50次以后）。没有生成崩溃日志，但是当连接到Xcode时，这样的输出会出现在导致崩溃的控制台中：

2016-11-04 20:30:11.884984 WLPBeta[2747:275474] [MC] Invalidating cache
2016-11-04 20:30:11.890776 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:30:13.017608 WLPBeta[2747:275091] [MC] Invalidating cache
2016-11-04 20:30:13.018312 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:30:19.271720 WLPBeta[2747:276311] [MC] Invalidating cache
2016-11-04 20:30:19.279462 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:08.229294 WLPBeta[2747:278515] [MC] Invalidating cache
2016-11-04 20:32:08.273941 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:09.335711 WLPBeta[2747:278514] [MC] Invalidating cache
2016-11-04 20:32:09.342161 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:14.193376 WLPBeta[2747:278515] [MC] Invalidating cache
2016-11-04 20:32:14.213902 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:47.944657 WLPBeta[2747:275091] [MC] Invalidating cache
2016-11-04 20:32:47.972053 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:48.550934 WLPBeta[2747:279485] [MC] Invalidating cache
2016-11-04 20:32:48.575065 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:50.855308 WLPBeta[2747:279485] [MC] Invalidating cache
2016-11-04 20:32:50.856329 WLPBeta[2747:273019] [MC] Reading from public effective user settings.
2016-11-04 20:32:52.201535 WLPBeta[2747:275091] [GatekeeperXPC] Connection to assetsd was interrupted or assetsd died

我还向Apple发布了一个错误报告，并将其添加到开放式雷达中：http://www.openradar.me/radar?id=4941109843197952

有没有人遇到过这个问题？是否有一个修复程序可以让我们在没有使用Xcode 8重新编译应用程序的情况下移过这个？不幸的是，我们正在使用尚未为Xcode 8和iOS 10 SDK做好准备的第三方库，因此我们仍在使用Xcode 7.3.1构建应用程序。

编辑：这里是一个Github repo的链接，其中包含一个可用于演示此问题的示例应用。

https://github.com/lolay/ImagePickerTest

编辑2：如果我更改代码以便在viewDidLoad中分配和初始化选择器，则在使用相机按钮的次数相同后，它仍然会崩溃。

- (void)viewDidLoad {
    [super viewDidLoad];
    self.picker = [[UIImagePickerController alloc] init];
    self.picker.sourceType =  UIImagePickerControllerSourceTypeCamera;
    self.picker.allowsEditing = NO;
}

- (IBAction) cameraPressed:(id) sender {
    [self presentViewController:self.picker animated:YES completion:nil];
}

Answer 1

您的UIImagePickerController定义为STRONG。

请在视图被破坏之前将其更改为弱或确保对象为零。

Answer 2

试试这段代码。

- (IBAction) cameraPressed:(id) sender {
   if (self.picker == nil){
      self.picker = [[UIImagePickerController alloc] init];
   }

    self.picker.sourceType =  UIImagePickerControllerSourceTypeCamera;
    self.picker.delegate = self;
    self.picker.allowsEditing = NO;
    [self presentViewController:self.picker animated:YES completion:nil];
}

Answer 3

您是否尝试在cameraPressed（）函数

中声明Imagepicker变量

- (IBAction) cameraPressed:(id) sender {
   UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.sourceType =  UIImagePickerControllerSourceTypeCamera;
    picker.delegate = self;
    picker.allowsEditing = NO;
    [self presentViewController:self.picker animated:YES completion:nil];
}

Answer 4

您需要明确驳回UIImagePickerController，即使它似乎是自动执行此操作。如果你不这样做，它可能会保留视图控制器，从而导致内存问题。

来自UIImagePickerControllerDelegate documentation：

如果将图像选择器的showsCameraControls属性设置为NO和提供您自己的自定义控件，您可以拍摄多张照片在解除图像选择器界面之前。但是，如果你设置它属性为YES，您的代理人必须关闭图像选择器界面用户拍摄一张照片或取消操作后。

默认情况下，该属性为YES，因此您需要关闭。

使用类似于以下的内容：

- (IBAction) cameraPressed:(id) sender {
    UIImagePickerController* picker = [[UIImagePickerController alloc] init];
    picker.sourceType =  UIImagePickerControllerSourceTypeCamera;
    picker.allowsEditing = NO;
    picker.delegate = self;
    [self presentViewController:picker animated:YES completion:nil];
}

- (void) imagePickerController:(UIImagePickerController *)picker
    didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void) imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

为什么我的应用程序在重复呈现和使用UIImagePickerControllers时会在iOS 10上崩溃？

4 个答案: