React Native setState不一致[重复]

Posted 2023-02-21

【中文标题】React Native setState不一致[重复]

【英文标题】：React Native setState is not consistant [duplicate]

【发布时间】：2018-12-23 14:53:20

【问题描述】：

这里我的状态在使用 setState.log 后没有更新，大部分时间显示默认值。为什么setState 不一致？

export default class Row extends Component 
  constructor(props) 
    super(props);

    // icons to listview (arrow icon)
    this.icons = 
      up: require("../../assets/ic_play_circle_down.png"),
      down: require("../../assets/ic_play_circle_up.png")
    ;

    this.state = 
      title: props.title,
      // getting screen size (width and height)
      let: ( width, height  = Dimensions.get("window")),

      // collapsed check the listview expanded or not if it is true: list view not expanded
      collapsed: true,

      isApproved: false,
      comment: "dummy comment"
    ;
  
  acceptApproval = () => 
    this.setState( isApproved: true );
    console.log("Approved TICK " + this.state.isApproved);
    this.verifyApprovals();
  ;

  regectApproval = () => 
    this.setState( isApproved: false );
    console.log("Approved" + this.state.isApproved);
    this.verifyApprovals();
  ;

【问题讨论】：

因为 setState 是异步的。

那我该如何解决呢？

这里你可以了解setState：medium.freecodecamp.org/…

【参考方案1】：

你知道setState是异步的，你应该调用你的第二个函数作为setState的回调

this.setState( isApproved: true , function()
   this._setApproval(true)
  );

  ;
_setApproval()
console.log("Approved TICK " + this.state.isApproved);
    this.verifyApprovals();


  regectApproval = () => 
    this.setState( isApproved: false  , function() 
    this._setRejection();
);

  ;

_setRejection() 
console.log("Approved" + this.state.isApproved);
    this.verifyApprovals();

【讨论】：

我解决了我的问题。我不知道“setState -> 异步”

好的..你能把工作的代码放在这里@HRCJ

acceptApproval = () => this.setState( isApproved: true, collapsed: !this.state.collapsed , function() this.verifyApprovals(); ); ;