Android开发调试Installation failed since the device possibly has stale dexed jars

今天写完代码运行时，出现了程序安装失败的对话框：

Installation failed since the device possibly has stale dexed jars that don't match the current version (dexopt error). In order to proceed, you have to uninstall the existing application.

WARNING: Uninstalling will remove the application data!

Do you want to uninstall the existing application?

已运行就是这样，死活没办法，最后搞了一晚上，终于找到了答案，AndroidStudio-> Build -> Clean Projects  然后等下面任务完成后，重新运行就可以了。