我尝试使用Class组件来实现这一点: 您可以查看相同的消息

…

class Checkbox extends React.Component{
constructor(props){
    super(props)
    this.state={
        checked:true
    }
    this.handleCheck=this.handleCheck.bind(this)
}

handleCheck(){
    this.setState({
        checked:!this.state.checked
    })
}

render(){
    var msg=" "
    if(this.state.checked){
        msg="checked!"
    }else{
        msg="not checked!"
    }
    return(
        <div>
            <input type="checkbox" 
            onChange={this.handleCheck}
            defaultChecked={this.state.checked}
            />
            <p>this box is {msg}</p>
        </div>
    )
}

}

Don't make it too hard. First, understand a simple example given below. It will be clear to you. In this case, just after pressing the checkbox, we will grab the value from the state(initially it's false), change it to other value(initially it's true) & set the state accordingly. If the checkbox is pressed for the second time, it will do the same process again. Grabbing the value (now it's true), change it(to false) & then set the state accordingly(now it's false again. The code is shared below.

第1部分

state = {
  verified: false
} // The verified state is now false

第2部分

verifiedChange = e => {
  // e.preventDefault(); It's not needed
  const { verified } = e.target;
  this.setState({
    verified: !this.state.verified // It will make the default state value(false) at Part 1 to true 
  });
}; 

第3部分

  <form> 
      <input
          type="checkbox"
          name="verified"
          id="verified"
          onChange={this.verifiedChange} // Triggers the function in the Part 2
          value={this.state.verified}
      />
      <label for="verified">
      <small>Verified</small>
      </label>
  </form>

您可以将"true"或""传递给input复选框的checked属性。空引号("")将被理解为假的，该项将不被选中。

let checked = variable === value ? "true" : "";
<input
     className="form-check-input"
    type="checkbox"
    value={variable}
    id={variable}
    name={variable}
    checked={checked}
/>
<label className="form-check-label">{variable}</label>

<div className="display__lbl_input">
              <input
                type="checkbox"
                onChange={this.handleChangeFilGasoil}
                value="Filter Gasoil"
                name="Filter Gasoil"
                id=""
              />
              <label htmlFor="">Filter Gasoil</label>
            </div>

handleChangeFilGasoil = (e) => {
    if(e.target.checked){
        this.setState({
            checkedBoxFG:e.target.value
        })
        console.log(this.state.checkedBoxFG)
    }
    else{
     this.setState({
        checkedBoxFG : ''
     })
     console.log(this.state.checkedBoxFG)
    }
  };

在我的情况下，我觉得“defaultChecked”不能正常工作的状态/条件。所以我用“checked”和“onChange”来切换状态。

Eg.

checked={this.state.enabled} onChange={this.setState({enabled : !this.state.enabled})}

除了正确答案，你还可以这样做:P

<input name="remember" type="checkbox" defaultChecked/>