Adding Server Side code Blocks in custom pages using sharepoint designer

In some situation we might require to add server side code in sharepoint.Generally we can do this by adding the server side code aspx in layout folder.For example, I need to run one custom aspx with server side code, then i need to place this file under layouts folder.so that i can call this page in sharepoint.But this page is under file system and not in the sharepoint content DB.

Here we are trying to explore how to add a custom code in custom page using sharepoint desinger.

To demonstra this, add a new .aspx page from sharepoint designer.

add the below code...

Add this configuration to web.config file