这次给大家带来React.js之props,使用React.js的props注意事项有哪些,下面就是实战案例,一起来看一下。
父组件向子组件传值
<Son userid={123}/>
在Son组件接收父组件传递过来的值
<p>接收到的父页面的属性 -- userid: {this.props.userid} username:{this.props.username}</p>
当然也可以在Son页面设置传递参数的类型和默认值
// 给属性设置类型BodyIndex.propTypes = { // isRequired 必须的参数 userid: React.PropTypes.number.isRequired, username: React.PropTypes.string }// 设置默认值BodyIndex.defaultProps = { username: '哈哈'}
设置类型具体参考官方文档
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.' ); } }) };
Son组件把从父组件传递过来的属性传递到孙子组件
通过展开运算符{...this.props},把从父组件传递过来的属性,全部传递给自己的子组件(孙子组件)
id={1234} 为Son组件自己传递给孙子组件的属性
<GrandSon {...this.props} id={1234}/>
在孙子组件调用从Son组件传递过来的属性
<p>{this.props.userid} {this.props.username} {this.props.id}</p>
refs: 是访问到组件内部 DOM 节点唯一可靠的方法
给标签添加ref
<input ref='submitButton' type="button" value='提交' onClick={() => this.changeUserInfo(99)}/>
当想要获取该dom时,通过this.refs.xxx获取
this.refs.submitButton.style.color = 'red';
注意:
不要在 render 或 render 之前对 Refs 进行调用;
不要滥用 Refs,能不使用,就不要使用!!!
相信看了本文案例你已经掌握了方法,更多精彩请关注php中文网其它相关文章!
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以上就是React.js之props的详细内容,更多请关注php中文网其它相关文章!
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