77 lines
1.4 KiB
Markdown
77 lines
1.4 KiB
Markdown
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---
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title: React - Components
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localeTitle: 反应 - 组件
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---
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## 反应 - 组件
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组件可在react.js中重用。您可以将值注入道具,如下所示:
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```jsx
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function Welcome(props) {
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return <h1>Hello, {props.name}</h1>;
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}
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const element = <Welcome name="Faisal Arkan" />;
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ReactDOM.render(
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element,
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document.getElementById('root')
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);
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```
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`name="Faisal Arkan"`将从`function Welcome(props)`赋予`{props.name}`值,并返回已通过`name="Faisal Arkan"`赋予值的组件,之后反应将元素转换为html。
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### 声明组件的其他方法
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使用React.js时,有许多方法可以声明组件,但有两种组件, **_无状态_**组件和**_有状态_**组件。
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### 有状态
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#### 类类型组件
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```jsx
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class Cat extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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humor: 'happy'
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}
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}
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render() {
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return(
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<div>
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<h1>{this.props.name}</h1>
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<p>
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{this.props.color}
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</p>
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</div>
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);
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}
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}
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```
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### 无状态组件
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#### 功能组件(ES6的箭头功能)
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```jsx
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const Cat = props => {
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return (
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<div>
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<h1>{props.name}</h1>
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<p>{props.color}</p>
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</div>;
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);
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};
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```
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#### 隐式返回组件
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```jsx
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const Cat = props =>
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<div>
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<h1>{props.name}</h1>
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<p>{props.color}</p>
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</div>;
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```
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