下面是一个使用按钮在组件之间切换的完整工作示例

可以按如下方式设置构造函数

constructor(props)
{
    super(props);
    this.state={
        currentView: ''
    }
}

然后您就可以像下面这样渲染组件了

  render() 
{
    const switchView = () => {

    switch(this.state.currentView) 
    {

      case "settings":   return <h2>settings</h2>;
      case "dashboard":   return <h2>dashboard</h2>;

      default:      return <h2>dashboard</h2>
    }
  }

    return (

       <div>

            <button onClick={(e) => this.setState({currentView: "settings"})}>settings</button>
            <button onClick={(e) => this.setState({currentView: "dashboard"})}>dashboard</button>

            <div className="container">
                { switchView() }
            </div>


        </div>
    );
}

}

正如你所看到的，我正在使用一个按钮来切换状态。

我将接受的答案转换为箭头功能组件解决方案，看到James提供了类似的答案，可以得到未定义的错误。这就是解决方案:

  const renderSwitch = (param) => {
    switch (param) {
      case "foo":
        return "bar";
      default:
        return "foo";
    }
  };

  return (
    <div>
      <div></div>

      {renderSwitch(param)}

      <div></div>
    </div>
  );

如何:

mySwitchFunction = (param) => {
   switch (param) {
      case 'A':
         return ([
            <div />,
         ]);
      // etc...
   }
}
render() {
    return (
       <div>
          <div>
               // removed for brevity
          </div>

          { this.mySwitchFunction(param) }

          <div>
              // removed for brevity
          </div>
      </div>
   );
}

我在render()方法中做了这个:

  render() {
    const project = () => {
      switch(this.projectName) {

        case "one":   return <ComponentA />;
        case "two":   return <ComponentB />;
        case "three": return <ComponentC />;
        case "four":  return <ComponentD />;

        default:      return <h1>No project match</h1>
      }
    }

    return (
      <div>{ project() }</div>
    )
  }

我试图保持render()返回干净，所以我把我的逻辑放在一个'const'函数上面。这样我也可以缩进我的开关盒整齐。

我们可以直接使用useCallback来做到这一点

const renderContent = useCallback(() => { switch (sortState) { “一”: 返回“一”; “两个”: 返回“两个”; “三”: 返回“三”; “四”: 返回“四”; 默认值: 返回“一”; ｝ }, [sortState]);

这将在jsx中使用

<div>排序：{renderContent（）}</div>

这个答案专门用来解决@tonyfat提出的“重复”问题，关于如何使用条件表达式来处理相同的任务。

---

Avoiding statements here seems like more trouble than it's worth, but this script does the job as the snippet demonstrates:

// Runs tests let id = 0, flag = 0; renderByFlag(id, flag); // jobId out of range id = 1; // jobId in range while(++flag < 5){ // active flag ranges from 1 to 4 renderByFlag(id, flag); } // Defines a function that chooses what to render based on two provided values function renderByFlag(jobId, activeFlag){ jobId === 1 ? ( activeFlag === 1 ? render("A (flag = 1)") : activeFlag === 2 ? render("B (flag = 2)") : activeFlag === 3 ? render("C (flag = 3)") : pass(`flag ${activeFlag} out of range`) ) : pass(`jobId ${jobId} out of range`) } // Defines logging functions for demo purposes function render(val){ console.log(`Rendering ${val}`); } function pass(reason){ console.log(`Doing nothing (${reason})`) }