If you want to add more complex features to your application, you can look at and use the code in the notepad application that is supplied in the sample code area of the Android SDK.

• 你可以在每个练习中逐步进行，慢慢构建、修改你的程序。每个练习都详细说明了每个步骤并提供了示例代码以帮助你完成记事本应用。