react之相关组件API

学习参考资料;菜鸟教程；

react入门教程实例-阮一峰；

一.无状态组件：没有生命周期，没有数据传递，只是用于view层显示；

import React,{Component} from "react"; // 引入react库文件// 创建组件export default ()=>{  return(        <div>            我是无状态组件！        </div>     )}

上面只是创建组件，如何引入组件是非常简单的，想要知道，可以在上一节（react数据传递那块）去了解这个组件的完整的创建过程；

ReactDOM.render 是 React 的最基本方法，用于将模板转为 HTML 语言，并插入指定的 DOM 节点；

引用于：http://www.ruanyifeng.com/blog/2015/03/react.html；（react入门教程实列）

正因为这个，我们组件的内外部的引入；

class Index extends Component{//创建内部组件    render(){        return(            <div>                              <Nostate></Nostate>{//外部组件引入；               }            </div>    )  }}ReactDOM.render(<div>  我是谁的人！  <Index />{    //内部组件引入；  }  </div>,document.getElementById("root"))

组件的引包省略；

react不存在双向数据绑定：可以模拟双向数据绑定；通过event.target方法去改变；

this.state={              txt:""             }render(){       return(      <div>                     <input type="text"  onChange={this.chang.bind(this)} />            {this.state.txt}      </div>    )     }chang(event){ this.setState({txt:event.target.value})}

接下来要讲一下，关于propTypes的这个东西；

引入：

cnpm install prop-types --saveimport PropTypes from 'prop-types'就是类型检测，检查代码bug

import PropTypes from 'prop-types';MyComponent.propTypes = {  // You can declare that a prop is a specific JS primitive. By default, these  // are all optional.  optionalArray: PropTypes.array,  optionalBool: PropTypes.bool,  optionalFunc: PropTypes.func,  optionalNumber: PropTypes.number,  optionalObject: PropTypes.object,  optionalString: PropTypes.string,  optionalSymbol: PropTypes.symbol,  // Anything that can be rendered: numbers, strings, elements or an array  // (or fragment) containing these types.  optionalNode: PropTypes.node,  // A React element.  optionalElement: PropTypes.element,  // You can also declare that a prop is an instance of a class. This uses  // JS's instanceof operator.  optionalMessage: PropTypes.instanceOf(Message),  // You can ensure that your prop is limited to specific values by treating  // it as an enum.  optionalEnum: PropTypes.oneOf(['News', 'Photos']),  // An object that could be one of many types  optionalUnion: PropTypes.oneOfType([    PropTypes.string,    PropTypes.number,    PropTypes.instanceOf(Message)  ]),  // An array of a certain type  optionalArrayOf: PropTypes.arrayOf(PropTypes.number),  // An object with property values of a certain type  optionalObjectOf: PropTypes.objectOf(PropTypes.number),  // An object taking on a particular shape  optionalObjectWithShape: PropTypes.shape({    color: PropTypes.string,    fontSize: PropTypes.number  }),  // You can chain any of the above with `isRequired` to make sure a warning  // is shown if the prop isn't provided.  requiredFunc: PropTypes.func.isRequired,  // A value of any data type  requiredAny: PropTypes.any.isRequired,  // You can also specify a custom validator. It should return an Error  // object if the validation fails. Don't `console.warn` or throw, as this  // won't work inside `oneOfType`.  customProp: function(props, propName, componentName) {    if (!/matchme/.test(props[propName])) {      return new Error(        'Invalid prop `' + propName + '` supplied to' +        ' `' + componentName + '`. Validation failed.'      );    }  },  // You can also supply a custom validator to `arrayOf` and `objectOf`.  // It should return an Error object if the validation fails. The validator  // will be called for each key in the array or object. The first two  // arguments of the validator are the array or object itself, and the  // current item's key.  customArrayProp: PropTypes.arrayOf(function(propValue, key, componentName, location, propFullName) {    if (!/matchme/.test(propValue[key])) {      return new Error(        'Invalid prop `' + propFullName + '` supplied to' +        ' `' + componentName + '`. Validation failed.'      );    }  })};