我试图通过使用这样的嵌套属性来组织我的状态:

this.state = {
   someProperty: {
      flag:true
   }
}

但是像这样更新状态,

this.setState({ someProperty.flag: false });

是行不通的。怎样才能正确地做到这一点呢?


当前回答

你可以用对象展开来做这个 代码:

 this.setState((state)=>({ someProperty:{...state.someProperty,flag:false}})

这将适用于更多嵌套的属性

其他回答

如果你在你的项目中使用formik,它有一些简单的方法来处理这些东西。下面是使用formik最简单的方法。

首先在formik initivalues属性或react中设置初始值。状态

这里,初始值是在react状态下定义的

   state = { 
     data: {
        fy: {
            active: "N"
        }
     }
   }

在formik initiValues属性中定义以上的initialValues字段

<Formik
 initialValues={this.state.data}
 onSubmit={(values, actions)=> {...your actions goes here}}
>
{({ isSubmitting }) => (
  <Form>
    <Field type="checkbox" name="fy.active" onChange={(e) => {
      const value = e.target.checked;
      if(value) setFieldValue('fy.active', 'Y')
      else setFieldValue('fy.active', 'N')
    }}/>
  </Form>
)}
</Formik>

制作一个控制台来检查状态更新为字符串而不是布尔值formik setFieldValue函数来设置状态或使用react调试器工具来查看formik状态值的变化。

这样就足够了,

const isObject = (thing) => {
    if(thing && 
        typeof thing === 'object' &&
        typeof thing !== null
        && !(Array.isArray(thing))
    ){
        return true;
    }
    return false;
}

/*
  Call with an array containing the path to the property you want to access
  And the current component/redux state.

  For example if we want to update `hello` within the following obj
  const obj = {
     somePrimitive:false,
     someNestedObj:{
        hello:1
     }
  }

  we would do :
  //clone the object
  const cloned = clone(['someNestedObj','hello'],obj)
  //Set the new value
  cloned.someNestedObj.hello = 5;

*/
const clone = (arr, state) => {
    let clonedObj = {...state}
    const originalObj = clonedObj;
    arr.forEach(property => {
        if(!(property in clonedObj)){
            throw new Error('State missing property')
        }

        if(isObject(clonedObj[property])){
            clonedObj[property] = {...originalObj[property]};
            clonedObj = clonedObj[property];
        }
    })
    return originalObj;
}

const nestedObj = {
    someProperty:true,
    someNestedObj:{
        someOtherProperty:true
    }
}

const clonedObj = clone(['someProperty'], nestedObj);
console.log(clonedObj === nestedObj) //returns false
console.log(clonedObj.someProperty === nestedObj.someProperty) //returns true
console.log(clonedObj.someNestedObj === nestedObj.someNestedObj) //returns true

console.log()
const clonedObj2 = clone(['someProperty','someNestedObj','someOtherProperty'], nestedObj);
console.log(clonedObj2 === nestedObj) // returns false
console.log(clonedObj2.someNestedObj === nestedObj.someNestedObj) //returns false
//returns true (doesn't attempt to clone because its primitive type)
console.log(clonedObj2.someNestedObj.someOtherProperty === nestedObj.someNestedObj.someOtherProperty) 

使用箭头函数代替,这应该做的把戏。

setItems((prevState) => {
   prevState.nestedData = newNestedData;
   prevState.nestedData1 = newNestedData1;
});

不要忘记使用箭头函数(prevState) =>{更新js赋值语句…}

stateUpdate = () => {
    let obj = this.state;
    if(this.props.v12_data.values.email) {
      obj.obj_v12.Customer.EmailAddress = this.props.v12_data.values.email
    }
    this.setState(obj)
}

用于多个输入控件和动态嵌套名称

<input type="text" name="title" placeholder="add title" onChange={this.handleInputChange} />
<input type="checkbox" name="chkusein" onChange={this.handleInputChange} />
<textarea name="body" id="" cols="30" rows="10" placeholder="add blog content" onChange={this.handleInputChange}></textarea>

代码非常易读

处理程序

handleInputChange = (event) => {
        const target = event.target;
        const value = target.type === 'checkbox' ? target.checked : target.value;
        const name = target.name;
        const newState = { ...this.state.someProperty, [name]: value }
        this.setState({ someProperty: newState })
    }