import React from "react";
import { render } from "react-dom";
import { createStore, applyMiddleware } from "redux";
import { Provider, connect } from "react-redux";
import thunk from "redux-thunk";

const disabled = (state = true, action) => {
  return action.type === "TOGGLE" ? !state : state;
};

class Button extends React.Component {
  componentDidUpdate(prevProps) {
    if (prevProps.disabled !== this.props.disabled && !this.props.disabled) {
      //  this.ref.focus();  // uncomment this to see the desired effect
    }
  }
  render() {
    const { props } = this;
    console.log("rendering", props.value);
    return (
      <div>
        <input
          type="checkbox"
          onClick={() => {
            props.toggle();
            this.ref.focus(); // doesn't work
          }}
        />
        <input
          disabled={props.disabled}
          ref={ref => {
            this.ref = ref;
          }}
        />
      </div>
    );
  }
}

const toggle = () => ({
  type: "TOGGLE"
});

const A = connect(state => ({ disabled: state }), { toggle })(Button);

const App = () => (
  <Provider store={createStore(disabled, applyMiddleware(thunk))}>
    <A />
  </Provider>
);

render(<App />, document.getElementById("root"));

我想在选中复选框时聚焦 input。 但是，this.ref.focus() 必须仅在组件使用 props.disabled === false 重新呈现后调用，作为 输入 with disabled prop 无法聚焦。

如果我执行 componentDidUpdate 中的逻辑，我就能实现我想要的。但这不是一个干净的解决方案，因为逻辑特定于 onClick 处理程序而不是生命周期事件。

还有其他方法可以实现吗？ (最好有一个有效的codesandbox示例)

最佳答案

我认为最好的办法是不依赖 refs 使用状态来管理焦点。

此解决方案改为在输入上使用 autoFocus 属性，并在复选框状态更改时修改它。

import React from "react";
import { render } from "react-dom";
import { createStore, applyMiddleware } from "redux";
import { Provider, connect } from "react-redux";
import thunk from "redux-thunk";

const disabled = (state = true, action) => {
  return action.type === "TOGGLE" ? !state : state;
};

class Button extends React.Component {
  state = {
    checked: false,
    focus: false
  };
  componentDidUpdate(prevProps, prevState) {
    if (prevState.checked !== this.state.checked) {
      this.props.toggle();
      this.setState({
        focus: this.state.checked
      });
    }
  }
  render() {
    const { props } = this;
    const { checked, focus } = this.state;
    console.log("rendering", props.value, checked);
    return (
      <div>
        <input
          type="checkbox"
          checked={checked}
          onClick={({ target }) => {
            this.setState({ checked: target.checked });
          }}
        />
        <input key={`input_${checked}`} autoFocus={focus} />
      </div>
    );
  }
}

const toggle = () => ({
  type: "TOGGLE"
});

const A = connect(state => ({ disabled: state }), { toggle })(Button);

const App = () => (
  <Provider store={createStore(disabled, applyMiddleware(thunk))}>
    <A />
  </Provider>
);

render(<App />, document.getElementById("root"));

我不确定为什么，但是在组件先前被禁用时更改 autoFocus 属性不会触发重新呈现输入。所以我还在输入中添加了一个键来强制它。

关于javascript - Redux-thunk 派发一个 Action 并等待重新渲染，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/49892010/