Connections to the SharePoint server are currently disabled because the project is in Offline mode

While developing and deploying SharePoint add-in using visual studio 2015 I got the error which says:

Connections to the SharePoint server are currently disabled because the project is in Offline mode. To connect to the SharePoint server, switch to Online mode by setting the project's server connection property to Online, an then try the opertaion again. The full error looks like below:

Solution:
Open Visual Studio 2015 solution -> Select the Project -> Click F4->Properties->Server Connection

Now we can deploy the project without any error.