您使用Eclipse？如果看到的Eclipse编译一个jar文件，它不一定包含到APK。 （您不得不提到的jar在几个地方，通常人们不多少地方记不清了。）

Are you using Eclipse? If Eclipse sees a jar file for compilation, it does not necessarily include it into the apk. (You have to mention the jar in several places, and usually people do not remember in how many places.)

ritht单击 - 构建路径 - 配置构建路径 - 订单和出口

ritht-click on the project name -- build path -- configure build path -- order and export.

同样的对话框中有一个项目选项卡，这是，您可以指定取决于项目。

The same dialog has a Projects tab, this is where you specify projects you depend on.

如果不工作，把罐子到项目的库子目录。

If that does not work, put the jar into the libs subdirectory of your project.