47 lines
1.4 KiB
Markdown
47 lines
1.4 KiB
Markdown
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---
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title: Pass a Callback as Props
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localeTitle: 将回调作为道具传递
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---
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## 将回调作为道具传递
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### 描述
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* 将`GetInput`组件添加到MyApp中的render方法，然后将一个名为`inpu`的prop从`inputValue`的状态传递给`inputValue` 。还要创建一个名为`handleChange`的prop，并将输入处理程序`handleChange`给它。
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* 将`RenderInput`添加到MyApp中的render方法，然后创建一个名为`input`的prop，并将`inputValue`从state传递给它。
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### 提示
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* `state`是一个属性`Myapp`类，所以用“this.state”来获取对象的值
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* 要了解有关状态和道具的更多信息，请阅读[状态和生命周期](https://reactjs.org/docs/state-and-lifecycle.html)以及[组件和道具](https://reactjs.org/docs/components-and-props.html) 。
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### 解
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```javascript
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class MyApp 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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inputValue: ''
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}
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this.handleChange = this.handleChange.bind(this);
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}
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handleChange(event) {
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this.setState({
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inputValue: event.target.value
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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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{ /* change code below this line */
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<GetInput input={this.state.inputValue} handleChange={this.handleChange}/>
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}
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{ /* change code above this line */
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<RenderInput input={this.state.inputValue}/>
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}
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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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