I am using below code inside document ready function
toastr.clear();
toastr.options.closeButton = true;
toastr.info('Message with a close button', '');
and its working fine. i have confusion to call mentioned function in controller.
I would recommend using an Angular toastr instead: https://github.com/Foxandxss/angular-toastr
Then you are away from the pain of integrating jQuery with Angular.
Right way is to create directive for calling jquery plugins. But if it's quick fix you can inject $element into controller. Here related question.
toastrobject will be available there