索引正确时未定义离子4子数组

Question

我已尝试使用console.log查看该值，但noticeSet2 [index]值未定义。当我打印noticeSet时，它将显示数组中的所有数据。而且我尝试在console.log上打印索引，它显示与数组匹配的索引。

我尝试在一个主菜单的子菜单中创建一个子菜单，该子菜单为noticeSet，并且主菜单工作正常。我尝试了类似的方法，但它不起作用。我现在需要解决的就是显示noticeSet2 [index]值。谢谢

toggleItem(index, item) {

    //this.noticeSet2[index].open = !this.noticeSet2[index].open;

    console.log("here");
    console.log(this.noticeSet2[0]);
    console.log(this.noticeSet2[index]);
    console.log(index);

    let obj = {resident_id: this.resident_id,id: item.id}

    this.authService.postData(obj, "getSubCategoryList").then((result) =>{
      this.responseData = result;
        if(this.responseData.feedData){
          //this.noticeSet2[item.id] = this.responseData.feedData;
          this.noticeSet3[this.noticeSet2[item.id]] = this.responseData.feedData;
          this.isDataAvailable = true;
        //console.log(this.noticeSet);
        }
      }, (err) => {
      });
  }



<ion-list *ngFor="let item of noticeSet; let i = index;" lines="none"  class="accordion-list" detail="false"
    no-padding >

    <button ion-item tappble style="font-weight:bold;color:#424242;" (click)="getSubCategoryList(i,item)" [ngClass]="{'section-active':item.open,'section':!item.open}">
      <ion-icon item-right slot="end" name="arrow-forward" *ngIf="!item.open"
        style="font-size: 16px;font-weight: bold;"></ion-icon>
      <ion-icon item-right slot="end" name="arrow-down" *ngIf="item.open"
        style="font-size: 16px;font-weight: bold;color:rgb(74, 137, 220)"></ion-icon>
      {{ item.title }}
    </button>


    <div *ngIf="noticeSet2[item.id] && item.open">
      <ion-list *ngFor="let item of noticeSet2[item.id]; let j = index;" lines="none" class="child-list">
        <button ion-item  (click)="toggleItem(j,item)" *ngIf="item.title"
          [ngClass]="{'child-active':item.open, 'child':!item.open}">
          <ion-icon item-left slot="start" name="add" *ngIf="!item.open" style="font-size: 12px;font-weight: bold;">
          </ion-icon>
          <ion-icon item-left slot="start" name="close" *ngIf="item.open" style="font-size: 12px;font-weight: bold;">
          </ion-icon>
          <ion-label>
            {{ item.title }}
          </ion-label>
        </button>

        <div *ngIf="noticeSet3[this.noticeSet2[item.id]] && item.open">
         <ion-list  *ngFor="let item of noticeSet3[this.noticeSet2[item.id]]" class="child-list-list" lines="none">
          <ion-item class="child-item" *ngIf="item.title">
            <button ion-item >
              {{item.title}}
            </button>
          </ion-item>
        </ion-list>
      </div>

      </ion-list>
    </div>
  </ion-list>

Answer 1

这是因为您在承诺中使用了价值。您可以通过两种方式进行：

第一个使用

。then（（）=> {[...]}

而不是

。then（（result）=> {[...]}

它将起作用。

第二个是在{}中使用特殊变量。

<ion-list *ngFor="let item of noticeSet; let i = index;" lines="none"  class="accordion-list" detail="false"
    no-padding >

    <button ion-item tappble style="font-weight:bold;color:#424242;" (click)="getSubCategoryList(i,item)" [ngClass]="{'section-active':item.open,'section':!item.open}">
      <ion-icon item-right slot="end" name="arrow-forward" *ngIf="!item.open"
        style="font-size: 16px;font-weight: bold;"></ion-icon>
      <ion-icon item-right slot="end" name="arrow-down" *ngIf="item.open"
        style="font-size: 16px;font-weight: bold;color:rgb(74, 137, 220)"></ion-icon>
      {{ item.title }}
    </button>


    <div *ngIf="noticeSet2[item.id] && item.open">
      <ion-list *ngFor="let item of noticeSet2[item.id]; let j = index;" lines="none" class="child-list">
        <button ion-item  (click)="toggleItem(j,item)" *ngIf="item.title"
          [ngClass]="{'child-active':item.open, 'child':!item.open}">
          <ion-icon item-left slot="start" name="add" *ngIf="!item.open" style="font-size: 12px;font-weight: bold;">
          </ion-icon>
          <ion-icon item-left slot="start" name="close" *ngIf="item.open" style="font-size: 12px;font-weight: bold;">
          </ion-icon>
          <ion-label>
            {{ item.title }}
          </ion-label>
        </button>

        <div *ngIf="noticeSet3[this.noticeSet2[item.id]] && item.open">
         <ion-list  *ngFor="let item of noticeSet3[this.noticeSet2[item.id]]" class="child-list-list" lines="none">
          <ion-item class="child-item" *ngIf="item.title">
            <button ion-item >
              {{item.title}}
            </button>
          </ion-item>
        </ion-list>
      </div>

      </ion-list>
    </div>
  </ion-list>

希望获得帮助。