In ubuntu 12.04, the R file cannot be generated for the new ADT project.

Cause: It is not clear that the SDK Tools version does not match the ADT version, usually because the SDK Tools version is low.

First, build automatically on the project --> hook, and then clean. This usually requires steps.

Then run sudo chmod-r a + x SDK/in the terminal directory /. In this way, the android SDK manager in the ADT can be executed.

Next, download the first three items in tools in Android SDK manager of ADT.

Restart eclipse.

 

PS: It took a week.