Q:

Create Custom Control in SharePoint Sandbox

I came across to a requirement to create User Control via sandbox.
I had done it previously using FARM solution. But finding no way to
   do it with sandbox. Can any one help and guide me how can I develop user-control using sandbox? 

A:

you can use SharePoint power tools to create visual webpart....but user control is not possible in sandbox because user controls needs to be deployed in physical folder(layouts)....You can get Visual designer capablities while developeing webpart using SharePoint power tools. Follow below link to do so..
https://marketplace.visualstudio.com/items?itemName=MikeMortonMSFT.VisualStudio2010SharePointPowerTools

