iOS之訪問權限以及跳轉到系統界面

iOS開發中有時候有這樣的需求：當用戶設置不允許訪問照片、麥克風和相機等系統權限的時候，這時需要直接跳轉到系統的隱私界面進行設置。

判斷是否開啟權限

前面已經說過，我們需要在用戶不允許訪問的時候跳轉，那么首先我們就要判斷一些是否已經開啟系統相機權限了。

照片權限檢測

需要：#import <AssetsLibrary/AssetsLibrary.h> //導入此類和AssetsLibrary.framework框架

代碼如下：

int author = [ALAssetsLibrary authorizationStatus]; NSLog(@"author type:%d",author); if(author == ALAuthorizationStatusRestricted || author == ALAuthorizationStatusDenied) { // The user has explicitly denied permission for media capture. UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"無法使用相冊" message:@"請在iPhone的\"設置-隱私-照片\"中允許訪問照片。" delegate:self cancelButtonTitle:@"確定" otherButtonTitles:nil]; [alert show]; return;

ALAssetsLibrary類

ALAssetsLibrary類是代表系統中整個資源庫，使用它可以訪問資源庫中的資源和保存照片，視頻等功能。

    //判斷當前應用是否能訪問相冊資源 /* typedef NS_ENUM(NSInteger, ALAuthorizationStatus) { ALAuthorizationStatusNotDetermined = 0, 用戶尚未做出了選擇這個應用程序的問候 ALAuthorizationStatusRestricted, 此應用程序沒有被授權訪問的照片數據。可能是家長控制權限。 ALAuthorizationStatusDenied, 用戶已經明確否認了這一照片數據的應用程序訪問. ALAuthorizationStatusAuthorized 用戶已授權應用訪問照片數據. } */

訪問攝像頭

需要：#import <AVFoundation/AVFoundation.h>

代碼如下：

if(isIOS7AndLater) { NSString *mediaType = AVMediaTypeVideo;// Or AVMediaTypeAudio AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType]; NSLog(@"---cui--authStatus--------%d",authStatus); // This status is normally not visible—the AVCaptureDevice class methods for discovering devices do not return devices the user is restricted from accessing. if(authStatus ==AVAuthorizationStatusRestricted){ NSLog(@"Restricted"); }else if(authStatus == AVAuthorizationStatusDenied){ // The user has explicitly denied permission for media capture. NSLog(@"Denied"); //應該是這個，如果不允許的話 UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"請在設備的\"設置-隱私-相機\"中允許訪問相機。" delegate:self cancelButtonTitle:@"確定" otherButtonTitles:nil]; [alert show]; return; } else if(authStatus == AVAuthorizationStatusAuthorized){//允許訪問 // The user has explicitly granted permission for media capture, or explicit user permission is not necessary for the media type in question. NSLog(@"Authorized"); }else if(authStatus == AVAuthorizationStatusNotDetermined){ // Explicit user permission is required for media capture, but the user has not yet granted or denied such permission. [AVCaptureDevice requestAccessForMediaType:mediaType completionHandler:^(BOOL granted) { if(granted){//點擊允許訪問時調用 //用戶明確許可與否，媒體需要捕獲，但用戶尚未授予或拒絕許可。 NSLog(@"Granted access to %@", mediaType); } else { NSLog(@"Not granted access to %@", mediaType); } }]; }else { NSLog(@"Unknown authorization status"); } }

麥克風權限檢測

代碼如下：

  //檢測麥克風功能是否打開 [[AVAudioSessionsharedInstance]requestRecordPermission:^(BOOL granted) { if (!granted) { [ViewUtilalertViewWithString:NSLocalizedString(@"麥克風功能未開啟",nil)]; } else { [selfrecord:sender]; } }];

如何跳轉到系統設置界面

判斷權限是否設置之后就可以在相應的代理方法進行界面跳轉了，那么如何進行跳轉呢？

首先要在項目中的info.plist中添加 URL types 並設置一項URL Schemes為prefs，如下圖：

1.jpg

實現代碼如下：

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:url]];//url為具體路徑

以下是跳轉到一些常用界面的代碼

隱私->照片界面

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=Privacy&path=PHOTOS"]];

隱私->相機界面

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=Privacy&path=CAMERA"]];

藍牙設置界面

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=Bluetooth"]];

其他界面參數配置

About — prefs:root=General&path=About

Accessibility — prefs:root=General&path=ACCESSIBILITY

Airplane Mode On — prefs:root=AIRPLANE_MODE

Auto-Lock — prefs:root=General&path=AUTOLOCK

Brightness — prefs:root=Brightness

Bluetooth — prefs:root=General&path=Bluetooth

Date & Time — prefs:root=General&path=DATE_AND_TIME

FaceTime — prefs:root=FACETIME

General — prefs:root=General

Keyboard — prefs:root=General&path=Keyboard

iCloud — prefs:root=CASTLE

iCloud Storage & Backup — prefs:root=CASTLE&path=STORAGE_AND_BACKUP

International — prefs:root=General&path=INTERNATIONAL

Location Services — prefs:root=LOCATION_SERVICES

Music — prefs:root=MUSIC

Music Equalizer — prefs:root=MUSIC&path=EQ

Music Volume Limit — prefs:root=MUSIC&path=VolumeLimit

Network — prefs:root=General&path=Network

Nike + iPod — prefs:root=NIKE_PLUS_IPOD

Notes — prefs:root=NOTES

Notification — prefs:root=NOTIFICATIONS_ID

// 

@"prefs:root=NOTIFICATIONS_ID&path=應用的boundleId"

Phone — prefs:root=Phone

Photos — prefs:root=Photos

Profile — prefs:root=General&path=ManagedConfigurationList

Reset — prefs:root=General&path=Reset

Safari — prefs:root=Safari

Siri — prefs:root=General&path=Assistant

Sounds — prefs:root=Sounds

Software Update — prefs:root=General&path=SOFTWARE_UPDATE_LINK

Store — prefs:root=STORE

Twitter — prefs:root=TWITTER

Usage — prefs:root=General&path=USAGE

VPN — prefs:root=General&path=Network/VPN

Wallpaper — prefs:root=Wallpaper

Wi-Fi — prefs:root=WIFI

文／小球hy（簡書作者）
原文鏈接：http://www.jianshu.com/p/1fb3f60b689a
著作權歸作者所有，轉載請聯系作者獲得授權，並標注“簡書作者”。