I want to import an csv file in my app. I search but found solution only for iOS 4. So my question is that is their any way of making file sharing enable and to import file from an email attachment?
2nd if not then what you suggest for importing a csv file in my app when using.
The solution for iOS 4 link is: http://www.raywenderlich.com/1948/how-integrate-itunes-file-sharing-with-your-ios-app
You can't do this before iOS 4 it was one of the features. You have already said it is possible in iOS 4.
Upgrade to the latest Xcode (3.2.6, or 4 if you want to pay $5, both are used to target iOS 4.3)
You can then set the deployment target to iOS 3.1 but depending on how file sharing is implemented you may have to add in some if statements to hide things from the user which will not work (like file sharing)