iOS開發(fā)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(tǒng)權限的時候蛾派，這時需要直接跳轉到系統(tǒng)的隱私界面進行設置。
判斷是否開啟權限
前面已經(jīng)說過，我們需要在用戶不允許訪問的時候跳轉海蔽，那么首先我們就要判斷一些是否已經(jīng)開啟系統(tǒng)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\"中允許訪問照片绑谣。"
delegate:self
cancelButtonTitle:@"確定"
otherButtonTitles:nil];
[alert show];
return;
ALAssetsLibrary類
ALAssetsLibrary類是代表系統(tǒng)中整個資源庫党窜，使用它可以訪問資源庫中的資源和保存照片，視頻等功能借宵。
//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(shù)據(jù)幌衣。可能是家長控制權限壤玫。
ALAuthorizationStatusDenied, 用戶已經(jīng)明確否認了這一照片數(shù)據(jù)的應用程序訪問.
ALAuthorizationStatusAuthorized 用戶已授權應用訪問照片數(shù)據(jù).
}
*/
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"); //應該是這個豁护，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
//用戶明確許可與否欲间，媒體需要捕獲楚里，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(tǒng)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猎贴，那么如何進行跳轉呢班缎？
首先要在項目中的info.plist中添加 URL types 并設置一項URL Schemes為prefs蝴光，如下圖：
實現(xiàn)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(shù)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
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
