react-native - React Native错误消息: Trying to add a root view with an explicit id already set

Question

我目前正在使用 React Native 开发一个应用程序。依据是Ignite 。目前，当我启动应用程序时，我经常收到一条我不理解的错误消息。也许有人可以告诉我它说了什么或如何解决问题。

Trying to add a root view with an explicit id already set. React Native uses the id field to track react tags and will overwrite this field. If that is fine, explicitly overwrite the id field to View.NO_ID before calling addRootView.
addRootViewGroup
    NativeViewHierarchyManager.java:504
addRootView
    NativeViewHierarchyManager.java:496
addRootView
    UIViewOperationQueue.java:572
registerRootView
    UIImplementation.java:129
addRootView
    UIManagerModule.java:211
attachRootViewToInstance
    ReactInstanceManager.java:897
setupReactContext
    ReactInstanceManager.java:855
access$1000
    ReactInstanceManager.java:109
run
    ReactInstanceManager.java:821
handleCallback
    Handler.java:739
dispatchMessage
    Handler.java:95
dispatchMessage
    MessageQueueThreadHandler.java:31
loop
    Looper.java:148
run
    MessageQueueThreadImpl.java:194
run
    Thread.java:818

我不确定需要哪些信息来帮助我，但这些至少是我的项目的依赖项(来自 package.json):

"dependencies": {
  "apisauce": "^0.14.0",
  "babel-preset-expo": "^4.0.0",
  "format-json": "^1.0.3",
  "lodash": "^4.17.2",
  "native-base": "^2.3.2",
  "prop-types": "^15.5.10",
  "querystringify": "0.0.4",
  "ramda": "^0.24.1",
  "react": "16.0.0-alpha.12",
  "react-native": "0.48.4",
  "react-native-animatable": "^1.2.4",
  "react-native-config": "^0.6.0",
  "react-native-elements": "^0.17.0",
  "react-native-i18n": "^2.0.6",
  "react-native-responsive-ui": "^1.1.1",
  "react-native-simple-encryption": "^1.2.1",
  "react-native-swiper": "^1.5.13",
  "react-native-vector-icons": "^4.4.0",
  "react-navigation": "^1.0.0-beta.13",
  "react-redux": "^5.0.2",
  "redux": "^3.6.0",
  "redux-persist": "^4.1.0",
  "redux-saga": "^0.15.6",
  "reduxsauce": "0.4.1",
  "seamless-immutable": "^7.0.1"
},
"devDependencies": {
  "@storybook/addon-storyshots": "^3.2.12",
  "@storybook/react-native": "^3.2.12",
  "babel-jest": "21.2.0",
  "babel-plugin-ignite-ignore-reactotron": "^0.3.0",
  "babel-preset-es2015": "^6.18.0",
  "babel-preset-react-native": "3.0.2",
  "enzyme": "^2.6.0",
  "husky": "^0.13.1",
  "ignite-ir-boilerplate": "^2.1.1",
  "jest": "21.2.1",
  "mockery": "^2.0.0",
  "react-addons-test-utils": "~15.4.1",
  "react-dom": "16.0.0-alpha.12",
  "react-test-renderer": "16.0.0-alpha.12",
  "reactotron-react-native": "^1.12.0",
  "reactotron-redux": "^1.11.1",
  "reactotron-redux-saga": "^1.11.1"
},

Answer 1

我注意到，当您在导出组件后声明变量或属性时，会发生这种情况。例如，如果您执行以下操作:

export default SignInLayout extends React.Component {
    render() {
        <Header />
        <Content />
        <Footer />
    }
}

const styles = Stylesheet.create({
    red: {
      color: red
    }
});

您收到错误尝试添加已设置显式 ID 的 Root View 。

要解决此问题，请在导出组件之前将变量声明向上移动。或者，您仍然可以通过将上面的代码更改为仅在最后导出组件来将变量声明保留在底部。

SignInLayout extends React.Component {
    render() {
        <Header />
        <Content />
        <Footer />
    }
}

const styles = Stylesheet.create({
    red: {
      color: red
    }
});

export default SignInLayout;