Error after eclipse changes JDK version

In the actual development process, we may need to change the JDK version for the project. However, after the replacement will be an error, as follows:

Java compiler level does not match the version of the installed Java project facet.

Workaround:

First step: Set up the Eclipse JDK version

Windows---->preferences---->java---->installed JREs

650) this.width=650; "Src=" http://images2015.cnblogs.com/blog/1120165/201703/ 1120165-20170322131723205-964319006.png "style=" margin:0px;padding:0px;border:none; "/>

Step two: Set the JDK build version

Windows---->preferences---->java---->compiler

650) this.width=650; "Src=" http://images2015.cnblogs.com/blog/1120165/201703/ 1120165-20170322132016627-991013106.png "style=" margin:0px;padding:0px;border:none; "/>

Step Three: Right-click the project and set the JDK version to the above unified

Right-click the project---->properties---->java Compiler

650) this.width=650; "Src=" http://images2015.cnblogs.com/blog/1120165/201703/ 1120165-20170322132216002-243556163.png "style=" margin:0px;padding:0px;border:none; "/>

Error after eclipse changes JDK version