export and import data from ListView WPF C# to Text file or Excel file

Instead of asking for an alternative for something that does not exist, you should clearly explain what it is that you are trying to do, what errors you are getting, what the code is that you are using when you get these errors. ListView.Items.SubItems has aboslutely nothing to do with your vague description of your problem. And you would probably benefit from reading this, http://www.codeproject.com/Articles/64628/Code-Project-Quick-Answers-FAQ

An answer to what? You have not clearly explained what it is that you are trying to do. You have not provided any kind of code that demonstrates your problem. You have not posted any kind of error message that you are getting. And you clearly have not read the posting guidelines for asking a question.