oracle_ 12505 error resolution

Log in today oracle Find out 12505 error , A lot of methods are not available ,

Finally found , In the installation directory D:\app\Lenovo\product\11.2.0\dbhome_1\NETWORK\ADMIN

find listener.ora and  tnsnames.ora, Open in Notepad , Backup before modification , If you don't have permission to modify, you can right-click to set the file properties , Give authority

Pay special attention to the localhost, hold localhost It can be solved by changing the computer name , Computer name can Right click -> We found

 

Save after modification . Here my computer is called LENVOV-PC