red cross issue on myeclipse project

Java compiler level does not match solution

method/step

 

1.  

   First set up the jdk, you need to determine the project, eclipse/myeclipse, the system uses the same version of JDK, the JDK installed in my system is 1.7, so I changed the jdk of eclipse to 1.7

   
2.  

   Enter windows---proferences---java--compiler to set the format of the compiled file to be version 1.7 (it can be set to any number, as long as it is compatible and it is always compatible with the compiled version of your project, I will set it uniformly here into 1.7)

   
3.  

   Enter the project --properties---java Compiler and set the project compilation version to 1.7

   
4.  

   Enter the project --properties---Myeclipse---project Facets to set the version of the java file to 1.7

   

5.