开发中有用到android-support-v4.jar，但一直没在意源码，今天想关联看下源码，根本没有关联的源码的选项，提示：
The Jar of this class file belongs to container 'Android Dependencies' which does not allow modifications to
source attachments on its entries.
仔细看了官方介绍，重做一遍，源码关联成功，步骤为:
1.移除 Android Dependencies
2.在libs下 右键 android-support-v4.jar Build Path ->Add To Build Path
Android官方介绍地址: http://developer.android.com/tools/extras/support-library.html#SettingUp