等到設置了“ this.state”的時間段后再運行功能

Question

我有一個按鈕，有3個狀態。 根據觸發的狀態，它應該進行提取以發布此數據。

基本上，我希望它等到this.state.favourite值設置超過200ms。 然后它應該觸發獲取。

它永遠不應該發布多個提取內容，

我嘗試使用_.debounce of lodash，但沒有任何效果。 它仍然立即運行該功能。

我也將其放在CodePen中 。

class Switch extends React.Component {
  constructor() {
    super();
    this.state = {
       favourite: 0
    }
  }

        handleClick() {
    this.setState((prevState) => ({
       favourite: (prevState.favourite + 1) % 3
    }));
    return _.debounce(this.favChosen(), 1000)
  }
  favChosen(){
    if (this.state.favourite === 0) {
    return this.testConsole1();
  } else if (this.state.favourite === 1) {
    return this.testConsole2();
  } else if (this.state.favourite === 2) {
    return this.testConsole3();
  }
 testConsole1() {
    console.log('This will be a fetch 1')
  }
  testConsole2() {
    console.log('This will be a fetch 2')
  }
  testConsole3() {
    console.log('This will be a fetch 3')
  }
  render () {
    const { favourite } = this.state;
    const fill = favourite === 0 ? "grey" :
                 favourite === 1 ? "green" : "red";
    return (
        <button className="favStar" onClick={this.handleClick.bind(this)} >
      <svg width="100" height="100">
        <g>
          <path id="svg_2" d="m0,38l37,0l11,-38l11,38l37,0l-30,23l11,38l-30,-23l-30,23l11,-38l-30,-23l0,0z" stroke-linecap="null" stroke-linejoin="null" stroke-dasharray="null" stroke-width="0" fill={fill} />
        </g>
      </svg>
            </button>
    );
  }
}

React.render( <Switch />, document.getElementById( "page" ) );

Answer 1

您沒有正確使用debounce 。

  constructor() {
    super();
    this.state = {
       favourite: 0
    }

    this.favChosen = _.debounce(this.favChosenRaw, 1000);     
  }

  handleClick() {
    this.setState((prevState) => ({
       favourite: (prevState.favourite + 1) % 3
    }));

    this.favChosen()

  }
  favChosenRaw(){....

工作提琴：

http://codepen.io/anon/pen/GmELKo?editors=1010

Answer 2

觸發狀態更改操作的更好解決方案是在setState回調上調用該函數，而不是在調用該函數之前等待固定的時間。 您永遠不會知道更改狀態需要多長時間，而且等待足夠長的時間也會限制您的應用程序。 嘗試這個

class Switch extends React.Component {
  constructor() {
    super();
    this.state = {
       favourite: 0
    }
  }

  handleClick() {
    this.setState((prevState) => ({
       favourite: (prevState.favourite + 1) % 3
    }), () => {this.favChosen()});

  }
  favChosen(){
    if (this.state.favourite === 0) {
    return this.testConsole1();
  } else if (this.state.favourite === 1) {
    return this.testConsole2();
  } else if (this.state.favourite === 2) {
    return this.testConsole3();
  }
 testConsole1() {
    console.log('This will be a fetch 1')
  }
  testConsole2() {
    console.log('This will be a fetch 2')
  }
  testConsole3() {
    console.log('This will be a fetch 3')
  }
  render () {
    const { favourite } = this.state;
    const fill = favourite === 0 ? "grey" :
                 favourite === 1 ? "green" : "red";
    return (
        <button className="favStar" onClick={this.handleClick.bind(this)} >
      <svg width="100" height="100">
        <g>
          <path id="svg_2" d="m0,38l37,0l11,-38l11,38l37,0l-30,23l11,38l-30,-23l-30,23l11,-38l-30,-23l0,0z" stroke-linecap="null" stroke-linejoin="null" stroke-dasharray="null" stroke-width="0" fill={fill} />
        </g>
      </svg>
            </button>
    );
  }
}

React.render( <Switch />, document.getElementById( "page" ) );

CODEPEN