WARNING: Application does not specify an API level requirement!
Re-installation failed due to different application signatures.
You must perform a full uninstall of the application. WARNING: This will remove the application data!
Please execute 'adb uninstall com.example.android.apis' in a shell.
Launch canceled!
研究官方范例无疑是快速学习任何SDK的不二法门，Android自带samples文件夹工程的创建可以参考这里，下面是我在调试该工程时遇到的两个问题，如图示：
错误1
WARNING: Application does not specify an API level requirement!
解决方法：在Mainfest.xml文件中的<mainfest ...></mainfest>元素中添加<uses-sdk android:minSdkVersion="10" />。
错误2
Re-installation failed due to different application signatures.
You must perform a full uninstall of the application. WARNING: This will remove the application data!
Please execute 'adb uninstall com.example.android.apis' in a shell.
Launch canceled!
解决方法：按照错误提示说的，执行adb uninstall com.example.android.apis（adb命令在android‘s SDK目录下的platform-tools目录中），注意是在模拟器运行中执行此命令。
