引入
类似state，props也是为组件提供数据来源的方式，不同的是state是自己定义数据，props是接受组件外部数据。
直接上🌰
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="test"></div>
<script type="text/javascript" src="../js/react.development.js"></script>
<script type="text/javascript" src="../js/react-dom.development.js"></script>
<script type="text/javascript" src="../js/babel.min.js"></script>
<script type="text/babel">
// 1.创建组件
class Person extends React.Component{
render(){
console.log(this)
const {name,sex,age} = this.props
return (
<ul>
<li>姓名：{name}</li>
<li>性别：{sex}</li>
<li>年龄：{age}</li>
</ul>
)
}
}
ReactDOM.render(<Person name="jerry" sex="男" age="20"/>,document.getElementById('test'))
</script>
</body>
</html>
批量传递多组标签属性
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="test"></div>
<script type="text/javascript" src="../js/react.development.js"></script>
<script type="text/javascript" src="../js/react-dom.development.js"></script>
<script type="text/javascript" src="../js/babel.min.js"></script>
<script type="text/babel">
// 1.创建组件
class Person extends React.Component{
render(){
console.log(this)
const {name,sex,age} = this.props
return (
<ul>
<li>姓名：{name}</li>
<li>性别：{sex}</li>
<li>年龄：{age}</li>
</ul>
)
}
}
const p = {name:'老王头',sex:'男',age:'76'}
ReactDOM.render(<Person name="jerry" sex="男" age="20"/>,document.getElementById('test'))
//批量传递多组标签属性
ReactDOM.render(<Person {...p}/>,document.getElementById('test'))
</script>
</body>
</html>
限制传入的数据格式
在对数据格式进行限制时需要引入React资源包
<script type="text/javascript" src="../js/prop-types.js"></script>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="test"></div>
<script type="text/javascript" src="../js/react.development.js"></script>
<script type="text/javascript" src="../js/react-dom.development.js"></script>
<script type="text/javascript" src="../js/babel.min.js"></script>
<script type="text/javascript" src="../js/prop-types.js"></script>
<script type="text/babel">
// 1.创建组件
class Person extends React.Component{
render(){
console.log(this)
const {name,sex,age} = this.props
// this.props.name = 'jack' 会报错 因为props是只读的
return (
<ul>
<li>姓名：{name}</li>
<li>性别：{sex}</li>
<li>年龄：{age}</li>
</ul>
)
}
}
// 需求：对props传入的对象进行数据格式限制
// 对标签属性进行类型、必要性的限制
Person.propTypes = {
name:PropTypes.string.isRequired, //字符串&必填
age:PropTypes.number, //数值
sex:PropTypes.string, //数值
speak:PropTypes.func //限制speak为函数
}
// 制定默认标签属性值
Person.defaultProps = {
sex:'男',
age:1
}
ReactDOM.render(<Person name="jerry" sex="男" age="20"/>,document.getElementById('test'))
const p = {name:'老王头',sex:'男',age:'76'}
//批量传递多组标签属性
ReactDOM.render(<Person {...p}/>,document.getElementById('test'))
</script>
</body>
</html>
阅读代码依然能发现propTypes、defaultProps是给Person实例里的属性赋值，显然这可以在Person类里直接写赋值语句来省略Person.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="test"></div>
<div id="test1"></div>
<script type="text/javascript" src="../js/react.development.js"></script>
<script type="text/javascript" src="../js/react-dom.development.js"></script>
<script type="text/javascript" src="../js/babel.min.js"></script>
<script type="text/javascript" src="../js/prop-types.js"></script>
<script type="text/babel">
// 1.创建组件
class Person extends React.Component{
// 需求：对props传入的对象进行数据格式限制
static propTypes = {
name:PropTypes.string.isRequired, //字符串&必填
age:PropTypes.number, //数值
sex:PropTypes.string, //数值
speak:PropTypes.func //限制speak为函数
}
// 制定默认标签属性值
static defaultProps = {
sex:'男',
age:1
}
render(){
console.log(this)
const {name,sex,age} = this.props
// this.props.name = 'jack' 会报错 因为props是只读的
return (
<ul>
<li>姓名：{name}</li>
<li>性别：{sex}</li>
<li>年龄：{age}</li>
</ul>
)
}
}
ReactDOM.render(<Person name={100} sex="男" age="20"/>,document.getElementById('test'))
const p = {name:'老王头',sex:'男',age:'76'}
//批量传递多组标签属性
ReactDOM.render(<Person {...p}/>,document.getElementById('test1'))
</script>
</body>
</html>
看看效果
啊 奇妙的知识
