AppService : <strong>IApplicationService</strong>
{
    Task&lt;ListResultDto&lt;TaskListDto&gt;&gt; GetAll(GetAllTasksInput input);
}</pre>

<p>Defining an interface is not required, but suggested. By convention, all app services <strong>should</strong> implement <strong>IApplicationService</strong> interface in ABP (it&#39;s just an empty marker interface). I created a <strong>GetAll</strong> method to query tasks. To do that, I also defined the following DTOs:</p>

<pre lang="cs">
public class GetAllTask