Referencing a library project 引用一个库工程

To add a reference to a library project, follow these steps:

Make sure that both the project library and the application project that depends on it are in your workspace. If one of the projects is missing, import it into your workspace.
In the Package Explorer, right-click the dependent project and select Properties.
In the Properties window, select the "Android" properties group at left and locate the Library properties at right.
Click Add to open the Project Selection dialog.
From the list of available library projects, select a project and click OK.
When the dialog closes, click Apply in the Properties window.
Click OK to close the Properties window.

1.先导入需要引用的工程
2. 右键当前工程-属性-android-添加，对话框中选择对应的工程，APPLY，OK
即可