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react如何设置数据

2026-01-15 08:51:43React

设置数据的常见方法

在React中设置数据通常涉及组件的状态管理，可以通过以下几种方式实现：

使用useState Hook（函数组件）

import React, { useState } from 'react';

function MyComponent() {
  const [count, setCount] = useState(0);

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}

使用类组件的state

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = { count: 0 };
  }

  render() {
    return (
      <div>
        <p>Count: {this.state.count}</p>
        <button onClick={() => this.setState({ count: this.state.count + 1 })}>
          Increment
        </button>
      </div>
    );
  }
}

使用Context API共享数据

const MyContext = React.createContext();

function App() {
  const [value, setValue] = useState('default');

  return (
    <MyContext.Provider value={{ value, setValue }}>
      <ChildComponent />
    </MyContext.Provider>
  );
}

function ChildComponent() {
  const { value, setValue } = useContext(MyContext);
  return <button onClick={() => setValue('new value')}>{value}</button>;
}

使用Redux管理全局状态

import { createStore } from 'redux';
import { Provider, useSelector, useDispatch } from 'react-redux';

const reducer = (state = { count: 0 }, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return { count: state.count + 1 };
    default:
      return state;
  }
};

const store = createStore(reducer);

function Counter() {
  const count = useSelector(state => state.count);
  const dispatch = useDispatch();

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => dispatch({ type: 'INCREMENT' })}>Increment</button>
    </div>
  );
}

function App() {
  return (
    <Provider store={store}>
      <Counter />
    </Provider>
  );
}