recharge() {
        let actionSheet = this._actionSheetCtrl.create({
            title: ‘付款详情‘,
            buttons: [{
                text: ‘确认付款‘,
                handler: () => {
                    let navTransition = actionSheet.dismiss();
                    navTransition.then(() => {
                        this.nav.push(RechargeSucceed);
                    })
                }
            }]
        });
        actionSheet.present();
    }