Android开发之IllegalStateException: You need to use a Theme.AppCompat theme解决方法

Android开发之

问题：

Process: cn.manager.iot.iotmanager, PID: 31617
java.lang.RuntimeException: Unable to start activity ComponentInfo{cn.manager.iot.iotmanager/cn.manager.iot.iotmanager.LoginActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
…
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

解决方法：