How to highlight or unhighlight search key when input value ion-searchbar

[hoangphan92]

I want to unhighlight search key but I can not find a solution. Please help me ! Thank a lot ^^
This is my code:

 <div class="map">
        <form action=".">
            <ion-searchbar #searchbar placeholder="{{'AreaSearch'|translate}}" [(ngModel)]="searchKey" (change)="searchKeyboard(searchKey)" [ngModelOptions]="{standalone: true}"></ion-searchbar>
        </form>
    <div id="map" #map></div>
 </div>