系统权限

• 在访问相机、相册等，需在info.plist里配置上请求权限的描述信息
  举个栗子：
  <key>NSCameraUsageDescription</key>
  <string>描述信息</string>
  下面列出所有的key，用到的自行添加吧。
  NSBluetoothPeripheralUsageDescription
  NSCalendarsUsageDescription
  NSCameraUsageDescription
  NSContactsUsageDescription
  NSHealthShareUsageDescription
  NSHealthUpdateUsageDescription
  NSHomeKitUsageDescription
  NSLocationAlwaysUsageDescription
  NSLocationWhenInUseUsageDescription
  NSMicrophoneUsageDescription
  NSMotionUsageDescription
  NSPhotoLibraryUsageDescription
  NSRemindersUsageDescription
  NSSiriUsageDescription
  NSSpeechRecognitionUsageDescription
  NSVideoSubscriberAccountUsageDescription
  NSVoIPUsageDescription

App跳转设置

  openUrl:
  openURL: options: completionHandler:
  prefs:root=某项服务

若要跳转系统设置，需先再URL type中添加一个prefs值，如下图：

设置 url types.png

• iOS <= iOS7 , 只能跳转到 系统设置页面
  NSURL *url= [NSURL URLWithString:@"prefs:root=LOCATION_SERVICES"];
  if ([[UIApplication sharedApplication] canOpenURL:url]) {
  [[UIApplication sharedApplication] openURL:url];
  }

• iOS >= iOS8 && <= iOS9 ，支持跳转到设置界面及设置内层界面
  可以使用UIApplicationOpenSettingsURLString跳转到当前app设置

• iOS >= iOS10，支持跳转到自己应用设置，不支持跳转到系统设置
  NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
  UIApplication *application = [UIApplication sharedApplication];
  if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
  [application openURL:url options:@{} completionHandler:^(BOOL success) {
  if (completion) { completion(success); }
  }];
  }
  options可选值：UIApplicationOpenURLOptionUniversalLinksOnly。
  Value为布尔值，默认为False，如果Value为True，那么只有安装了Link所对应的App的情况下才能打开这个Universal Link，而不是通过启动Safari方式打开这个Link的代表的网站。
  [[UIApplication sharedApplication] openURL:URL options:@{UIApplicationOpenURLOptionUniversalLinksOnly:@YES} completionHandler:nil];

• iOS >= iOS8 可以这样
  - (void)openUrl:(NSString *)urlStr completiongHandler:(void (^ __nullable)(BOOL success))completion {
  NSURL *url = [NSURL URLWithString:urlStr];
  UIApplication *application = [UIApplication sharedApplication];
  if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
  [application openURL:url options:@{} completionHandler:^(BOOL success) {
  if (completion) { completion(success); }
  }];
  }
  else {
  BOOL success = false;
  if ([application canOpenURL:url]) {
  success = [application openURL:url];
  }
  if (completion) { completion(success); }
  }
  }
  调用
  // NSString *urlStr = @"prefs:root=Phone";
  NSString *urlStr = UIApplicationOpenSettingsURLString;
  [self openUrl:urlStr completiongHandler:^(BOOL success) {
  if (!success) {
  // 跳转失败
  }else {
  // 跳转成功
  }
  }];

• 以下列出一些系统设置的URL
  蜂窝网络：prefs:root=MOBILE_DATA_SETTINGS_ID
  VPN — prefs:root=General&path=Network/VPN
  Wi-Fi：prefs:root=WIFI
  定位服务：prefs:root=LOCATION_SERVICES
  个人热点：prefs:root=INTERNET_TETHERING
  关于本机：prefs:root=General&path=About
  辅助功能：prefs:root=General&path=ACCESSIBILITY
  飞行模式：prefs:root=AIRPLANE_MODE
  锁定：prefs:root=General&path=AUTOLOCK
  亮度：prefs:root=Brightness
  蓝牙：prefs:root=General&path=Bluetooth
  时间设置：prefs:root=General&path=DATE_AND_TIME
  FaceTime：prefs:root=FACETIME
  设置：prefs:root=General
  键盘设置：prefs:root=General&path=Keyboard
  iCloud：prefs:root=CASTLE
  iCloud备份：prefs:root=CASTLE&path=STORAGE_AND_BACKUP
  语言：prefs:root=General&path=INTERNATIONAL
  定位：prefs:root=LOCATION_SERVICES
  音乐：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
  Wallpaper — prefs:root=Wallpaper