这里是改变iOS模拟器的新路径，你只需要改变

default: 'iPhone 6' or something else 

路径:

<project_root>/node_modules/@react-native-community/cli/build/commands/runIOS/runIOS.js

修改/node_modules/react-native/local-cli/runIOS/findMatchingSimulator.js的行代码

线55

  if (
    simulator.availability !== '(available)' &&
    simulator.isAvailable !== true
  ) {
    continue;
  }

取代的:

   if (
                simulator.availability !== '(available)' &&
                simulator.isAvailable !== true
              ) {
                continue;
     }

使用——simulator标志指定一个模拟器。

以下是iOS 14.0之后可用的设备:

npx react-native run-ios --simulator="iPhone 8"
npx react-native run-ios --simulator="iPhone 8 Plus"
npx react-native run-ios --simulator="iPhone 11"
npx react-native run-ios --simulator="iPhone 11 Pro"
npx react-native run-ios --simulator="iPhone 11 Pro Max"
npx react-native run-ios --simulator="iPhone SE (2nd generation)"
npx react-native run-ios --simulator="iPhone 12 mini"
npx react-native run-ios --simulator="iPhone 12"
npx react-native run-ios --simulator="iPhone 12 Pro"
npx react-native run-ios --simulator="iPhone 12 Pro Max"
npx react-native run-ios --simulator="iPhone 13 Pro"
npx react-native run-ios --simulator="iPhone 13 Pro Max"
npx react-native run-ios --simulator="iPhone 13 mini"
npx react-native run-ios --simulator="iPhone 13"
npx react-native run-ios --simulator="iPod touch (7th generation)"
npx react-native run-ios --simulator="iPad Pro (9.7-inch)"
npx react-native run-ios --simulator="iPad (9th generation)"
npx react-native run-ios --simulator="iPad Air (4th generation)"
npx react-native run-ios --simulator="iPad Pro (11-inch) (3rd generation)"
npx react-native run-ios --simulator="iPad Pro (12.9-inch) (5th generation)"
npx react-native run-ios --simulator="iPad mini (6th generation)"

列出所有可用的iOS设备:

xcrun simctl list devices

目前没有办法设置默认值。

React Native Docs:在模拟器上运行

对于RN 0.64.2，配置位于node_modules/@react-native-community/cli-platform-ios/build/commands/runIOS/index.js，您可以修改文件中的默认模拟器

正如Ian L所回答的，我也使用NPM来管理我的脚本。

例子: { "脚本":{ “ios”:“react-native run-ios——模拟器=\"iPad Air 2\""， “设备”:“xcrun simctl list设备” ｝ ｝

这样，我可以很快得到我需要的东西:

列出所有设备:npm run devices 运行默认模拟器:npm Run ios

1)重命名你的模拟器，如果模拟器与相同的名称，但不同的iOS版本

Xcode -> Window -> Devices and Simulators -> Simulators.

2)打开react原生项目文件夹

3)编辑package.json

"scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest",
    "flow": "node_modules/.bin/flow",
    "start-iphone6": "react-native run-ios --simulator \"iPhone 6 11.3\""
}

4)运行NPM start-iphone6