Android Import Project Error resolution

Import Android source code, there are basic errors, R.java will not be automatically generated, because it is the first time to import engineering, engineering error R.java will not be automatically generated, the project has errors, of course, the simulator can not start, but also do not see the effect. Then online to find a variety of solutions, online solutions mainly have these kinds of

1. Select Menu Project >> Clean, if you tick on Bulid automatically (auto build deployment), click Clean to rebuild the project, because in general, The R.java file will be re-updated at this time, and will not be generated automatically if the project is wrong.

    Summary When importing other sources, The first step is to ensure that the SDK version of the source code is consistent with your eclipse default version.
View Source Version method: Open the Default.properties file to see how much this number is behind target=android-7.
Version correspondence: Target=android-3 <---> Android 1.5   ,target=android-4 <--- > Android 1.6,
target=android-7 <---> Android 2.1   ,target= Android-8 <---> Android 2.2 others under their own test.