调用alloc init时，UIImagePickerController确实很慢 [英] UIImagePickerController really slow when calling alloc init

问题描述

我有一个视图控制器，按下tabBarController中的一个选项卡。在此视图控制器中，我在viewDidLoad方法中初始化UIImagePickerController：

I have a view controller that is presented on pressing on one of the tabs in a tabBarController. In this view controller I initialise a UIImagePickerController in the viewDidLoad method:

- (void)viewDidLoad
{
    [super viewDidLoad];

    //Set imagePicker
    //-------------------------//
    _imagePicker = [[UIImagePickerController alloc] init];
    _imagePicker.delegate = self;
    _imagePicker.videoMaximumDuration = 10.0f;
}

目的是在稍后按钮显示时显示UIImagePickerController按下。出于某种原因，虽然为此视图控制器按下选项卡图标时，此viewDidLoad方法正在运行时有3-4秒的挂起。当我注释掉行_imagePicker = [[UIImagePickerController alloc] init]时，没有挂起时间，视图控制器立即加载 - 应该如此。

The intention is to then display the UIImagePickerController at a later time when a button is pressed. For some reason though when the tab icon is pressed for this view controller, there is a 3-4 second hang while this viewDidLoad method is running. When I comment out the line _imagePicker = [[UIImagePickerController alloc] init] there is no hang time and the view controller loads immediately - as it should.

有谁知道为什么分配和初始化UIImagePickerController需要这么长时间？如果是这样，除了将其作为后台进程运行之外，有没有办法加快速度？这似乎不是正常行为。

Does anyone know why allocating and initialising the UIImagePickerController is taking so long? If so, is there a way to speed it up other than running it as a background process? It seems like this is not normal behaviour.

我使用的是iOS7，我没有调用viewWillAppear或viewDidAppear。

I am using iOS7, and I am not calling viewWillAppear or viewDidAppear.

推荐答案

原来这只是在调试模式下（当iPhone连接并通过Xcode运行时）的一个问题。一旦相同的应用程序在没有连接到Xcode的情况下运行，就不会出现延迟。

Turns out this is only a problem when in debug mode (when the iPhone is connected and running through Xcode). Once the same app is running without being connected to Xcode the lag doesn't occur.

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