How to Attach Android Source-Code to eclipse?

Standard

After installing ADT, use SDK Manager to download the source codes for the latest android API.

Open SDK Manager–>install source under api(i.e Android 4.0)
if You got No sources attached then click the button, then choose the Directory
e.g: D:\Android\android___sdk\sources\android-17\ —> this my android sdk location
Depend upon your android installation directory choose accordingly.