RN 各种小问题

问题:vs code 无法启动 双击无反应

方法:控制台 输入 netsh winsock reset

   重启 vs

 

问题:RN Debugger Network 不显示

源网页:https://github.com/jhen0409/react-native-debugger/blob/master/docs/network-inspect-of-chrome-devtools.md

See the comments of node_modules/react-native/Libraries/Core/InitializeCore.js#L43-L53. It uses XMLHttpRequest from WebWorker in Chrome, basically it can manually setup by:

global.XMLHttpRequest = global.originalXMLHttpRequest
  ? global.originalXMLHttpRequest
  : global.XMLHttpRequest
global.FormData = global.originalFormData
  ? global.originalFormData
  : global.FormData

fetch // Ensure to get the lazy property

if (window.__FETCH_SUPPORT__) {
  // it's RNDebugger only to have
  window.__FETCH_SUPPORT__.blob = false
} else {
  /*
   * Set __FETCH_SUPPORT__ to false is just work for `fetch`.
   * If you're using another way you can just use the native Blob and remove the `else` statement
   */
  global.Blob = global.originalBlob ? global.originalBlob : global.Blob
  global.FileReader = global.originalFileReader
    ? global.originalFileReader
    : global.FileReader
}

 

RN 警告:

Warning: Can't call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.

方法来自 https://blog.csdn.net/softwarenb/article/details/81123389

方法 1:组件被销毁之前重写setState方法 不对状态做任何改变 

componentWillUnmount() {
        this.setState = (state, callback) => {
            return;
        };
    }

方法 2:组件被销毁之前可以 setState  销毁之后就不能 setState (待测)

componentWillMount() {
        this._isMounted = true
        fetch('网络请求').then(status, response) => {
            if (this._isMounted) {
                this.setState({
                    activityTipsImg: response.data.tips_url,
                    activityTipsContent: response.data.tips_content
                })
            }
        });
    }
    componentWillUnmount() {
        this._isMounted = false
    }

 

原文地址:https://www.cnblogs.com/gemeiyi/p/10019534.html