I want to convert aspx webapplication to webpart? Is there any tool to
convert directly? or need to write the manual code?..

Actually I have created a databased tree view menu (C# web application)to
place a leftstrip of the default.aspx. Now when I tried to merge with
default.aspx was giving error, later came to know that server control will
not support in site. I decided to convert as webpart. now If my application
contains lots of folders like links, image, bin(dll) etc. How do I
place/include while converting webpart. Please give some clue or help me to
convert aspx to webpart without struggling!