如何检测用户已单击"不允许访问摄像头"

Question

我正在使用a UIImagePicker来向用户展示相机以拍摄将在应用中使用的照片.

我的问题是,当用户第一次打开图像选择器时,他们会看到一个提示:'"我的应用程序"想要使用两个选项访问您的相机,不允许和确定.

我的要求是,当用户单击"不允许"时,图像选择器将被关闭,留下黑色视图.有没有办法检测用户选择了不允许？

这是我的代码UIImagePicker:

var PhotoPicker:UIImagePickerController = UIImagePickerController()
PhotoPicker.delegate = self
PhotoPicker.sourceType = .Camera
PhotoPicker.cameraFlashMode = .Off
PhotoPicker.showsCameraControls = false
PhotoPicker.cameraDevice = .Rear
self.presentViewController(PhotoPicker, animated: false, completion: nil)

Answer 1

要检测对库的访问:

您需要使用AssetsLibrary.一,导入资产库框架:

import AssetsLibrary

然后,请求授权状态,如果未确定,则使用块来捕获这些事件,如下所示:

if ALAssetsLibrary.authorizationStatus() == ALAuthorizationStatus.NotDetermined {

    let library = ALAssetsLibrary()
    library.enumerateGroupsWithTypes(.All, usingBlock: { (group, stop) -> Void in

        // User clicked ok
    }, failureBlock: { (error) -> Void in

        // User clicked don't allow
        imagePickerController.dismissViewControllerAnimated(true, completion: nil)
    })
}

要检测对相机的访问:

你需要使用AVFoundation.一,导入avfoundation框架:

import AVFoundation

然后,如前所述,当您转到imagepicker并捕获事件时请求用户权限.

if AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo) == AVAuthorizationStatus.NotDetermined {

    AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo, completionHandler: { (videoGranted: Bool) -> Void in

        // User clicked ok
        if (videoGranted) {

        // User clicked don't allow
        } else {
            imagePickerController.dismissViewControllerAnimated(true, completion: nil)
        }
    })
}

希望能帮助到你!