How to change the images dynamically inside for loop in angular6?

Question

My html code:

          <div class="row">
        <div class="col-xs-6 col-sm-6 col-md-4 col-lg-12">
           <ng-container *ngFor="let horizontal of categories">
            <ng-container *ngFor="let horizontalval of horizontal.items;let i=index">
          <button [ngClass]="{'selected-color' : i==selectedIndex}" type="submit" class="btn1" [id]="horizontal.items[i].title" (click)="changeTrans(horizontal.items[i].title);changeColor(i)"> 
            <img [src]= horizontal.items[i].icon alt="image not found" class="icon"/>
            {{ horizontal.items[i].title }}
          </button>
        </ng-container>
      </ng-container></div>
      </div>

So my component.ts file,

 changeColor(i){
  console.log(i);
this.selectedIndex = i;
}

my css:

.selected-color{
 background-color: orange;
 color:white;
// background-image: url('./../../../../../assets/Trans_1.png');
}

So here I am able to change the color of the selected button, but I also need to change different images for different values. Here, how can I change my image dynamically for every button id?

Basically what I want to know is, how to change the image dynamically for every button which is going to be displayed via for. Can anybody suggest me something to achieve it?

Answer 1

Replace the below code

<ng-container *ngFor="let horizontalval of horizontal.items;let i=index">

by

<img [attr.src]= "horizontalval.icon" alt="image not found" class="icon"/>

Edit

Note : object horizontalval should have attribute icon which will have path of image .

If you want to change the path for entire image then you can use selectedIndex .

<img [src]= "horizontal.items[selectedIndex].icon" class="icon"/>

Edit

    <button [ngClass]="{'selected-color' : horizontal.items[i].selected}" 
      type="submit" class="btn1" [id]="horizontal.items[i].title"
 (click)="changeTrans(horizontal.items[i].title);
         changeColor(horizontal.items[i])">        
       <img [src]= horizontal.items[i].icon alt="image not found" class="icon"/>
                {{ horizontal.items[i].title }}
      </button>

ts

changeColor(item){
  this.item.selected = true;
}