how to call object value ionic 2

问题:

After done the api calling. In my db I have set of json object values. The structure is look like this :

{
  "status": 1,
  "message": "List Successfully fetched",
  "CatgeoryList": [
    {
      "CatID": "10"

    },
{
      "CatID": "30"

    },
{

     "CatID": "0"

    }]
}

I have done api calling. And i get the status == 1. And i can print all the object values under in CatgeoryList. But i want to print all the catID UNDER IN CatgeoryList. i was not able to get.

here my code :

this.authService.categ(this.loginData).then((result) => {
      this.loading.dismiss();
      this.data = result;

       if(this.data.status == 1)
       {
       this.Catdata = this.data.CatgeoryList;  
      console.log(this.Catdata);  // i am getting all data

      this.Catdatanames = this.Catdata.CatID;  // not working
      console.log(this.Catdata.CatID); // not working
}
}

I want to get the catID underCatgeoryList.

Update :

Update of home.html:

  <div class="item item-body no-padding" style="border-width: 0px !important;">  

  <div class="row no-padding"  *ngFor="let data of Catdata;let i = index" (click)="opndetailpage()">
     <ng-container *ngIf=" i % 2 === 0">

          <div class="col col-50 custom-design2" style="background: url(url) no-repeat center;background-size: cover;">
               <div class="custom-design1"><span class="grid-title">{{Catdata[i].CategoryName}}</span></div>
            </div>

            <div class="col col-50 custom-design2" style="background: url(url) no-repeat center;background-size: cover;">
                 <div class="custom-design1"><span class="grid-title">{{Catdata[i+1].CategoryName}}</span></div>
             </div>


     </ng-container>
</div> 


</div>

home.ts

constructor(
    public alertCtrl: AlertController,
    public app: App,
    public loadingCtrl: LoadingController,
    public modalCtrl: ModalController,
    public navCtrl: NavController,
    public toastCtrl: ToastController,
    public confData: ConferenceData,
    public user: UserData,
    public http:Http,
    public authService: AuthService
  ) {

this.showLoader();
    this.authService.categ(this.loginData).then((result) => {
      this.loading.dismiss();
      this.data = result;

       if(this.data.status == 1)
       {
       this.Catdata = this.data.CatgeoryList;


           for(let i=0; i<this.Catdata.length; i++) {
               console.log(this.Catdata[i].CategoryName);
           }



       }

       else if(this.data.status == 0) {

     let alert = this.alertCtrl.create({
    title: 'Error',
    subTitle: 'Please Enter Valid Username & Password',
    buttons: ['OK']
  });
  alert.present();
       }

    }, (err) => {
      this.loading.dismiss();

    });     

  }

My takeexam.html

   <ion-buttons>
 <button (click)="canceltap()" style="font-size: 15px;text-transform: none;" ion-button>Cancel
    </button>
    </ion-buttons>

my takeexam.ts

canceltap() {
   // this.navCtrl.pop();
    console.log("pop tap");
    this.navCtrl.setRoot(TabsPage);  .// this is my home page


  }

so when i press cancel button in takeexam.html its going to tabp[age.html ( home page). But in that no data are showing. I just tried with hard code some value in my home page. That time when i press cancel button its showing all data.

so i found the problem is in shoing the data in ionviewdidload or some other. i tried.ionViewDidEnter ionDidLoad. but nothing works

回答1:

Since this.data.CatgeoryList is an array, you'll need to use a loop to do something with each item

this.authService.categ(this.loginData).then((result) => {
      this.loading.dismiss();
      this.data = result;

       if(this.data.status == 1) {
           // this.Catdata is an array
           this.Catdata = this.data.CatgeoryList;

           // Use a loop to print the items
           for(let i=0; i<this.Catdata.length; i++) {
               console.log(this.Catdata[i].CatID);
           }
       }
}

And if you want to show it in the view, you can use ngFor like this

<ion-list>
    <ion-item *ngFor="let item of Catdata">
        {{ item.CatID }}
    </ion-item>
</ion-list>

UPDATE

But if i want to get the catID by onclikc. MEANS that i need to pass that catID to my another page means. Ionic 2 by (click) how can i pass this catID To next page

Update the view

<ion-list>
    <ion-item (click)="showDetails(item.CatID)" *ngFor="let item of Catdata">
        {{ item.CatID }}
    </ion-item>
</ion-list>

You can add a new method on the component code

public showDetails(catId: any): void {
    this.navCtrl.push(AnotherPage, { catId: catId });
}

And in the second page, in the constructor, get the data by using NavParams

constructor(public params: NavParams){
   // userParams is an object we have in our nav-parameters
   this.catId = this.navParams.get('catId')
 }