react setState 状态更改

Question

  addEditChange(e,key){        let that = this;        let add_edit_form = that.state.add_edit_form;            add_edit_form[key] = e.target.value;        that.setState({            add_edit_form:add_edit_form        })        console.log(that.state.budget_form);    }            我 setState  add_edit_form  为啥budget_form里面的值也会变    

Answer 1

典型的shallow copy跟deep copy（某个地方add_edit_form 等于 budget_form了）， 你要改变的话最好用

import update from 'react-addons-update';

...

const add_edit_form = update(budget_form, {a: {$set: 'b'}})

//或者更新自己

const add_edit_form = update(this.state.add_edit_form, {a: {$set: 'b'}})

//新的add_edit_form是独一无二的，不回牵扯到之前的reference

this.setState({add_edit_form})

Answer 2

你的budget_form是不是就是add_edit_form

Answer 3

console.log(that.state.budget_form);  设置之前查看值

that.setState({

            add_edit_form:add_edit_form

},()=>{

 console.log(that.state.budget_form);  设置之后查看值  

})

看打印的是否一样