确定是否设置了对照片库的访问权限 - PHPhotoLibrary

Question

使用 iOS 8 中的新功能，如果您在应用程序中使用相机，它会请求访问相机的权限，然后当您尝试重新拍摄照片时，它会请求访问照片库的权限。下次我启动应用程序时，我希望检查相机和照片库是否具有访问权限。

对于相机，我检查它通过

if ([AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo] == AVAuthorizationStatusDenied)
{
// do something
}

我正在为照片库寻找类似的东西。

Answer 1

这里是 iOS 8+ 的完整指南（没有 ALAssetLibrary）：

首先，我们必须提供usage description，因为现在它是 PHPhotoLibrary必需的。
为此，我们必须打开文件info.plist，找到密钥Privacy - Photo Library Usage Description 并为其提供值。如果密钥不存在，则只需创建它。
这是一个图像示例：
还要确保Bundle name 键在info.plist 文件中的值不为空。

现在有了描述后，我们就可以正常调用requestAuthorization方法请求授权了：

[PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
    switch (status) {
        case PHAuthorizationStatusAuthorized:
            NSLog(@"PHAuthorizationStatusAuthorized");
            break;
        case PHAuthorizationStatusDenied:
            NSLog(@"PHAuthorizationStatusDenied");
            break;
        case PHAuthorizationStatusNotDetermined:
            NSLog(@"PHAuthorizationStatusNotDetermined");
            break;
        case PHAuthorizationStatusRestricted:
            NSLog(@"PHAuthorizationStatusRestricted");
            break;
    }
}];

注意 1： requestAuthorization 实际上不会在每次通话时都显示警报。它每隔一段时间显示一次，保存用户的答案并每次返回它，而不是再次显示警报。但由于这不是我们需要的，这里有一个有用的代码，每次我们需要权限时总是显示警报（重定向到设置）：

- (void)requestAuthorizationWithRedirectionToSettings {
    dispatch_async(dispatch_get_main_queue(), ^{
        PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
        if (status == PHAuthorizationStatusAuthorized)
        {
            //We have permission. Do whatever is needed
        }
        else
        {
            //No permission. Trying to normally request it
            [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
                if (status != PHAuthorizationStatusAuthorized)
                {
                    //User don't give us permission. Showing alert with redirection to settings
                    //Getting description string from info.plist file
                    NSString *accessDescription = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"NSPhotoLibraryUsageDescription"];
                    UIAlertController * alertController = [UIAlertController alertControllerWithTitle:accessDescription message:@"To give permissions tap on 'Change Settings' button" preferredStyle:UIAlertControllerStyleAlert];
                    
                    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil];
                    [alertController addAction:cancelAction];
                    
                    UIAlertAction *settingsAction = [UIAlertAction actionWithTitle:@"Change Settings" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
                        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
                    }];
                    [alertController addAction:settingsAction];
                    
                    [[UIApplication sharedApplication].keyWindow.rootViewController presentViewController:alertController animated:YES completion:nil];
                }
            }];
        }
    });
}

常见问题一： 部分用户complain 表示在info.plist 文件中进行上述更改后，应用程序没有显示警报。
解决方案：为了测试尝试将Bundle Identifier 从项目文件更改为其他内容，清理并重建应用程序。如果它开始工作，那么一切都很好，将其重命名。

常见问题 2： 当应用程序获得照片权限时，当获取结果未更新（并且使用这些获取请求中的图像的视图仍然为空）时，存在一些特定情况，按照文档中的承诺在运行时。
实际上，当我们像这样使用 WRONG 代码时会发生这种情况：

- (void)viewDidLoad {
    if ([PHPhotoLibrary authorizationStatus] != PHAuthorizationStatusAuthorized)
    {
        //Reloading some view which needs photos
        [self reloadCollectionView];
        // ...
    } else {
        [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
            if (status == PHAuthorizationStatusAuthorized)
                [self reloadCollectionView];
            // ...
        }];
    }
    // ...
}

在这种情况下，如果用户拒绝授予 viewDidLoad 的权限，然后跳转到设置、允许并跳转回应用程序，则不会刷新视图，因为 [self reloadCollectionView] 和获取请求未发送。
解决方案：我们只需要调用[self reloadCollectionView] 并在要求授权之前执行其他获取请求，如下所示：

- (void)viewDidLoad {
    //Reloading some view which needs photos
    [self reloadCollectionView];
    if ([PHPhotoLibrary authorizationStatus] != PHAuthorizationStatusAuthorized)
    {
        // ...
}

Answer 2

iOS 14 及更高版本 Apple 添加了一项新功能，可限制对照片库的访问。根据您的要求（例如创建自定义照片库），您必须检查用户是否仅授予有限访问权限并希望授予完全访问权限。

为了向后兼容，即使您获得有限访问权限，不带参数的旧版本也会返回 .authorized。

斯威夫特 5：

switch PHPhotoLibrary.authorizationStatus(for: .readWrite) {
case .notDetermined:
    // ask for access
case .restricted, .denied:
    // sorry
case .authorized:
    // we have full access
 
// new option: 
case .limited:
    // we only got access to some photos of library
}

有一个代码可以再次调用受限访问屏幕。如果用户仅授予 .limited 访问权限，并且您希望用户再次选择图像。

PHPhotoLibrary.shared().presentLimitedLibraryPicker(from: presentVCObj)

在应用程序每次重新启动时，iOS 都会显示警报以通知用户访问受限。如果您想停止该警报，请添加 PHPhotoLibraryPreventAutomaticLimitedAccessAlert 在 Info.plist

中为“是”

Answer 3

和形式一样，Swift 2.X 版本：

    func checkPhotoLibraryPermission() {
       let status = PHPhotoLibrary.authorizationStatus()
       switch status {
       case .Authorized:
            //handle authorized status
       case .Denied, .Restricted :
            //handle denied status
       case .NotDetermined:
            // ask for permissions
            PHPhotoLibrary.requestAuthorization() { (status) -> Void in
               switch status {
               case .Authorized:
                   // as above
               case .Denied, .Restricted:
                   // as above
               case .NotDetermined:
                   // won't happen but still
               }
            }
        }
    }

还有 Swift 3 / Swift 4：

    import Photos

    func checkPhotoLibraryPermission() {
        let status = PHPhotoLibrary.authorizationStatus()
        switch status {
        case .authorized: 
        //handle authorized status
        case .denied, .restricted : 
        //handle denied status
        case .notDetermined: 
            // ask for permissions
            PHPhotoLibrary.requestAuthorization { status in
                switch status {
                case .authorized: 
                // as above
                case .denied, .restricted: 
                // as above
                case .notDetermined: 
                // won't happen but still
                }
            }
        }
    }

Answer 4

我知道这已经得到解答，但只是为了扩展@Tim 的答案，这里是您需要的代码（iOS 8 及更高版本）：

PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];

if (status == PHAuthorizationStatusAuthorized) {
     // Access has been granted.
}

else if (status == PHAuthorizationStatusDenied) {
     // Access has been denied.
}

else if (status == PHAuthorizationStatusNotDetermined) {

     // Access has not been determined.
     [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {

         if (status == PHAuthorizationStatusAuthorized) {
             // Access has been granted.         
         }

         else {
             // Access has been denied.
         }
     }];  
}

else if (status == PHAuthorizationStatusRestricted) {
     // Restricted access - normally won't happen.
}

别忘了#import <Photos/Photos.h>

如果您使用的是 Swift 3.0 或更高版本，则可以使用以下代码：

// Get the current authorization state.
let status = PHPhotoLibrary.authorizationStatus()

if (status == PHAuthorizationStatus.authorized) {
    // Access has been granted.
}

else if (status == PHAuthorizationStatus.denied) {
    // Access has been denied.
}

else if (status == PHAuthorizationStatus.notDetermined) {

    // Access has not been determined.
    PHPhotoLibrary.requestAuthorization({ (newStatus) in

        if (newStatus == PHAuthorizationStatus.authorized) {

        }

        else {

        }
    })
}

else if (status == PHAuthorizationStatus.restricted) {
    // Restricted access - normally won't happen.
}

别忘了import Photos

Answer 5

更新：SWIFT 3 IOS10

---

注意：在 AppDelegate.swift 中导入 Photos 如下

// AppDelegate.swift

导入 UIKit

导入照片

...

---

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    photoLibraryAvailabilityCheck()

}

//MARK:- PHOTO LIBRARY ACCESS CHECK
func photoLibraryAvailabilityCheck()
{
    if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
    {

    }
    else
    {
        PHPhotoLibrary.requestAuthorization(requestAuthorizationHandler)
    }
}
func requestAuthorizationHandler(status: PHAuthorizationStatus)
{
    if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized
    {

    }
    else
    {
        alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
    }
}

//MARK:- CAMERA & GALLERY NOT ALLOWING ACCESS - ALERT
func alertToEncourageCameraAccessWhenApplicationStarts()
{
    //Camera not available - Alert
    let internetUnavailableAlertController = UIAlertController (title: "Camera Unavailable", message: "Please check to see if it is disconnected or in use by another application", preferredStyle: .alert)

    let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
        let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
        if let url = settingsUrl {
            DispatchQueue.main.async {
                UIApplication.shared.open(url as URL, options: [:], completionHandler: nil) //(url as URL)
            }

        }
    }
    let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
    internetUnavailableAlertController .addAction(settingsAction)
    internetUnavailableAlertController .addAction(cancelAction)
    self.window?.rootViewController!.present(internetUnavailableAlertController , animated: true, completion: nil)
}
func alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
{
    //Photo Library not available - Alert
    let cameraUnavailableAlertController = UIAlertController (title: "Photo Library Unavailable", message: "Please check to see if device settings doesn't allow photo library access", preferredStyle: .alert)

    let settingsAction = UIAlertAction(title: "Settings", style: .destructive) { (_) -> Void in
        let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
        if let url = settingsUrl {
            UIApplication.shared.open(url as URL, options: [:], completionHandler: nil)
        }
    }
    let cancelAction = UIAlertAction(title: "Okay", style: .default, handler: nil)
    cameraUnavailableAlertController .addAction(settingsAction)
    cameraUnavailableAlertController .addAction(cancelAction)
    self.window?.rootViewController!.present(cameraUnavailableAlertController , animated: true, completion: nil)
}

答案更新自Alvin George

Answer 6

Swift 2.0+

根据此处的答案组合，我为自己创建了一个解决方案。此方法仅检查是否没有权限。

我们有一个方法pickVideo() 需要访问照片。如果不是.Authorized 请求许可。

如果未授予权限，pickVideo() 将不会被调用，并且用户无法选择视频。

只要用户没有授予对照片的完全访问权限，您就可以避免让他们选择“或崩溃”您的应用程序。

  // Method that requires access to photos
  func pickVideo(){
    // Check for permission
    if PHPhotoLibrary.authorizationStatus() != .Authorized{
      // If there is no permission for photos, ask for it
      PHPhotoLibrary.requestAuthorization(requestAuthorizationHandler)
      return
    }
    //... pick video code here...
  }

  func requestAuthorizationHandler(status: PHAuthorizationStatus){
    if PHPhotoLibrary.authorizationStatus() == .Authorized{
      // The user did authorize, so, pickVideo may be opened
      // Ensure pickVideo is called from the main thread to avoid GUI problems
      dispatch_async(dispatch_get_main_queue()) {
        pickVideo()
      }
    } else {
      // Show Message to give permission in Settings
      let alertController = UIAlertController(title: "Error", message: "Enable photo permissions in settings", preferredStyle: .Alert)
      let settingsAction = UIAlertAction(title: "Settings", style: .Default) { (alertAction) in
        if let appSettings = NSURL(string: UIApplicationOpenSettingsURLString) {
          UIApplication.sharedApplication().openURL(appSettings)
        }
      }
      alertController.addAction(settingsAction)
      // If user cancels, do nothing, next time Pick Video is called, they will be asked again to give permission
      let cancelAction = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
      alertController.addAction(cancelAction)
      // Run GUI stuff on main thread
        dispatch_async(dispatch_get_main_queue()) {      
          self.presentViewController(alertController, animated: true, completion: nil)
        }
      }
    }

Answer 7

I have a simple solution on swift 2.0

//
//  AppDelegate.swift
//  HoneyBadger
//
//  Created by fingent on 14/08/15.
//  Copyright (c) 2015 fingent. All rights reserved.
//

import UIKit
import Photos

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        self.window?.makeKeyAndVisible()

             self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let initialViewController = storyboard.instantiateViewControllerWithIdentifier("LoginPageID")
            self.window?.rootViewController = initialViewController
            self.window?.makeKeyAndVisible()
        return true
    }
    func applicationDidEnterBackground(application: UIApplication) {
        print("Application On background", terminator: "")
    }
    func applicationDidBecomeActive(application: UIApplication) {
        cameraAllowsAccessToApplicationCheck()
        photoLibraryAvailabilityCheck()
    }
    //MARK:- CAMERA ACCESS CHECK
    func cameraAllowsAccessToApplicationCheck()
    {
        let authorizationStatus = AVCaptureDevice.authorizationStatusForMediaType(AVMediaTypeVideo)
        switch authorizationStatus {
        case .NotDetermined:
            // permission dialog not yet presented, request authorization
            AVCaptureDevice.requestAccessForMediaType(AVMediaTypeVideo,
                completionHandler: { (granted:Bool) -> Void in
                    if granted {
                        print("access granted", terminator: "")
                    }
                    else {
                        print("access denied", terminator: "")
                    }
            })
        case .Authorized:
            print("Access authorized", terminator: "")
        case .Denied, .Restricted:
            alertToEncourageCameraAccessWhenApplicationStarts()
        default:
            print("DO NOTHING", terminator: "")
        }
    }
    //MARK:- PHOTO LIBRARY ACCESS CHECK
    func photoLibraryAvailabilityCheck()
    {
        if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.Authorized
        {

        }
        else
        {
            PHPhotoLibrary.requestAuthorization(requestAuthorizationHandler)
        }
    }
    func requestAuthorizationHandler(status: PHAuthorizationStatus)
    {
        if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.Authorized
        {

        }
        else
        {
            alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
        }
    }

    //MARK:- CAMERA & GALLERY NOT ALLOWING ACCESS - ALERT
    func alertToEncourageCameraAccessWhenApplicationStarts()
    {
        //Camera not available - Alert
        let internetUnavailableAlertController = UIAlertController (title: "Camera Unavailable", message: "Please check to see if it is disconnected or in use by another application", preferredStyle: .Alert)

        let settingsAction = UIAlertAction(title: "Settings", style: .Destructive) { (_) -> Void in
            let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
            if let url = settingsUrl {
                dispatch_async(dispatch_get_main_queue()) {
                    UIApplication.sharedApplication().openURL(url)
                }

            }
        }
        let cancelAction = UIAlertAction(title: "Okay", style: .Default, handler: nil)
        internetUnavailableAlertController .addAction(settingsAction)
        internetUnavailableAlertController .addAction(cancelAction)
        self.window?.rootViewController!.presentViewController(internetUnavailableAlertController , animated: true, completion: nil)
    }
    func alertToEncouragePhotoLibraryAccessWhenApplicationStarts()
    {
//Photo Library not available - Alert
        let cameraUnavailableAlertController = UIAlertController (title: "Photo Library Unavailable", message: "Please check to see if device settings doesn't allow photo library access", preferredStyle: .Alert)

        let settingsAction = UIAlertAction(title: "Settings", style: .Destructive) { (_) -> Void in
            let settingsUrl = NSURL(string:UIApplicationOpenSettingsURLString)
            if let url = settingsUrl {
                UIApplication.sharedApplication().openURL(url)
            }
        }
        let cancelAction = UIAlertAction(title: "Okay", style: .Default, handler: nil)
        cameraUnavailableAlertController .addAction(settingsAction)
        cameraUnavailableAlertController .addAction(cancelAction)
        self.window?.rootViewController!.presentViewController(cameraUnavailableAlertController , animated: true, completion: nil)
    }
}

Answer 8

我是这样做的：

- (void)requestPermissions:(GalleryPermissions)block
{
    PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];

    switch (status) 
    {
        case PHAuthorizationStatusAuthorized:
            block(YES);
            break;
        case PHAuthorizationStatusNotDetermined:
        {
            [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus authorizationStatus)
            {
                if (authorizationStatus == PHAuthorizationStatusAuthorized)
                {
                    block(YES);
                }
                else
                {
                    block(NO);
                }
            }];
            break;
        }
        default:
            block(NO);
            break;
    }
}

我会根据成功或失败将我需要做的事情作为块发送。

Answer 9

这里是我常用的一个小而简单的sn-p。

- (void)requestPhotoAuthorization:(void (^)(BOOL granted))granted
{
    void (^handler)(PHAuthorizationStatus) = ^(PHAuthorizationStatus status)
    {
        if (status == PHAuthorizationStatusAuthorized) granted(YES);
        else if (status == PHAuthorizationStatusNotDetermined) [PHPhotoLibrary requestAuthorization:handler];
        else granted(NO);
    };
    handler([PHPhotoLibrary authorizationStatus]);
}

Answer 10

使用 ALAssetsLibrary 应该可以工作：

ALAuthorizationStatus status = [ALAssetsLibrary authorizationStatus];
switch (status) {
    case ALAuthorizationStatusNotDetermined: {
        // not determined
        break;
    }
    case ALAuthorizationStatusRestricted: {
        // restricted
        break;
    }
    case ALAuthorizationStatusDenied: {
        // denied
        break;
    }
    case ALAuthorizationStatusAuthorized: {
        // authorized
        break;
    }
    default: {
        break;
    }
}

Answer 11

检查+[PHPhotoLibrary authorizationStatus] - 如果未设置，它将返回PHAuthorizationStatusNotDetermined。 （然后您可以在同一个班级使用+requestAuthorization: 请求访问权限。）