I had developed azure function solution in Visual Studio 2019 and deployed to azure function by downloading publisher .
But accidently I had deleted entire source code in local machine where I could not get even from "recovery software tools" also.
is there any way can I get source code files from azure function development tools in azure portal? or local machine C drive?
When you deployed through Visual Studio, the source was compiled locally and only the DLLs were uploaded. Thus, you cannot directly see your code. However, you can get to your DLLs and download those. Then you should be able to use any decompiler to see your source code again (maybe not as pretty as originally...).
Go to the SCM console to see and download all files: https://{YOURFUNCTIONNAME}.scm.azurewebsites.net/dev/wwwroot/