this.setState(state, callback); The second parameter this.setState() accepts is the callback function, and that’s where you’ll want to add your side effects. This callback function will get triggered when React state has finished updating. this.setState(newStateObject, () => { // ...
的原因 --- 在第二次运行时,因为你不能 push 到一个数字。 您需要改用 Array.prototype.concat() 。它不会改变原始数组,而是返回一个包含新串联元素的新数组。这就是你想在里面做的 setState 。您的代码应如下所示: this.setState({ userAnswers: this.state.userAnswers.concat(this.state.value), questi...
warning: Cannot update a component (ArrayInput) while rendering a different component (SelectInput)marmelab/react-admin#4632 Closed TomJannesmentioned this issueApr 9, 2020 Warning: Cannot update a component (XXX) while rendering a different componentmarmelab/react-admin#4665 ...
// 对数据的状态进行变更toggleChecked(event){letchecked=event.target.checked;letindex=event.target.getAttribute("data-index");letlist=this.state.list;list[index].checked=checked;this.setState({list});},render(){// 将数组的数据渲染出来return({this.state.list...
Remember, whenever we are updating state, it's important that we always pass a new object/array tosetState. That's why we're using the spread operator here to make a copy of the array, instead of.push, which will mutate the original array. ...
It can be confusing, since React props are read-only, but Highcharts for performance reasons mutates the original data array. This behaviour is NOT changed by our wrapper. You need to pass a copy of your data to the wrapper if you want to prevent mutations. ...
if(!Array.prototype.map){Array.prototype.map=function(){// implement the method};}// usagetypeof[].map==='function';// true, `map()` is now usable A polyfill is a solution in pure JavaScript-land. It’s a good solution when adding new methods to existing objects or implementing new...
stateNode:保存Fiber对应的真实DOM节点 ref: 和key一样属于base字段 2.2 Fiber树结构实现 代码语言:html 复制 function FiberNode( tag: WorkTag, pendingProps: mixed, key: null | string, mode: TypeOfMode, ) { ... // Fiber this.return = null; ...
Fix crash on empty snapToOffsets array (145fd041c7 by @ryancat) Fix StatusBar not updating to use translucent values when set to the same value across different activities (d34a75e9e5) Fix underlineColorAndroid transparent not working on API 21 (52aee50a70 by @fabriziobertoglio1987) Fixed...
By updating the State based on user actions or asynchronous events, you can create components that respond to user input and reflect the changes in real time. To learn more about React JS check out Intellipaat’s React JS Course. Why Do We Need State in ReactJS? State is crucial in ...