Not working dynamic parameter through tab

Ionic Framework ionic-v3
1

export class TabsPage {

constructor(public navParams: NavParams) {
this.dataname=navParams.get(‘schoolname’);

}

tab1Root = AccountPage;
tab1Params = { schoolname: this.dataname };
tab2Root = RoomPage;
tab3Root = StudentPage;

}
}

2

The initializer executes before dataname is set.