[[UIApplication sharedApplication] openURL:url];
通过给url不同的值，可以实现调用系统自带 电话／短信／邮箱／浏览器／...
1、调用 电话phone
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://800888"]];
拨打电话之后不跳转回app
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"telprompt://800888"]];
拨打电话之后跳转回app
2、调用自带 浏览器safari
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://www.abt.com"]];
3、调用 自带Mail
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto://admin@abt.com"]];
4、调用 SMS
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"sms://800888"]];
5、调用 app Store
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://"]];
6、调用 iBook
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-books://"]];
7、调用 Map
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"maps://"]];
8、调用 Facetime
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"facetime://"]];
9、调用 Music
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"music://"]];
10、跳转到系统设置相关界面
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=WIFI"]];
以下为设置的跳转关键字
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
INTERNET_TETHERING Internet_tethering — prefs:root= INTERNET_TETHERING