zdeMacBook-Pro:sometest z$ react-native run-ios -h
react-native run-ios 

builds your app and starts it on iOS simulator

Options:
  --simulator [string]      Explicitly set simulator to use. Optionally include iOS version between parenthesis at the end to match an exact version: "iPhone 6 (10.0)" (default
 
: "iPhone 11")
  --configuration [string]  Explicitly set the scheme configuration to use (default: "Debug")
  --scheme [string]         Explicitly set Xcode scheme to use
  --project-path [string]   Path relative to project root where the Xcode project (.xcodeproj) lives. (default: "ios")
  --device [string]         Explicitly set device to use by name.  The value is not required if
 
 you have a single device connected.
  --udid [string]           Explicitly set device to use by udid
  --no-packager             Do not launch packager while building
  --verbose                 Do not use xcpretty even if installed
  --port [number]            (default: 8081)
  --terminal [string]       Launches the Metro Bundler in
 
 a new window using the specified terminal path. (default: "Apple_Terminal")
  -h, --help                output usage information

Example usage:
  Run on a different simulator, e.g. iPhone SE: 
  react-native run-ios --simulator "iPhone SE" //執行在模擬器命令

  Pass a non-standard location of iOS directory: 
  react-native run-ios --project-path "./app/ios"

  Run on a connected device, e.g. Max's iPhone: 
  react-native run-ios --device "Max's iPhone" //執行在iOS真機

  Run on the AppleTV simulator: 
  react-native run-ios --simulator "Apple TV"  --scheme "helloworld-tvOS"