Re-installation failed due to different application signatures

修改MainActivity.java文件后，再次在模拟器上运行，控制台输出错误，如下：

[2017-09-07 15:24:36 - Demo] Re-installation failed due to different application signatures.[2017-09-07 15:24:36 - Demo] You must perform a full uninstall of the application. WARNING: This will remove the application data![2017-09-07 15:24:36 - Demo] Please execute 'adb uninstall com.application.demo' in a shell.[2017-09-07 15:24:36 - Demo] Launch canceled!

按照第三句提示操作：

直接在模拟器上长按程序，拖到垃圾桶卸载。

或者

setting--管理应用程序--卸载

或者

打开cmd，切换到当前项目所在位置，执行：adb uninstall 应用的包名