ASP.NET Web Pages - Files

This chapter is about working with text files.

Working with Text Files

Sometimes you will want to access data stored in text files.

Text files used to store data is often called flat files.

Common flat file formats are .txt, .xml, and .csv (comma-delimited values).

In this chapter you will learn:

  • How to read and display data from a text file

Add a Text File Manually

In the example to follow, you will need a text file to work with.

On your web site, if you don't have an App_Data folder, create one.

In the App_Data folder, create a new file named Persons.txt.

Add the following content to the file:



Displaying Data from a Text File

The example below shows how to display data from a text file:  


var dataFile = Server.MapPath("~/App_Data/Persons.txt");
Array userData = File.ReadAllLines(dataFile);

<!DOCTYPE html>

<h1>Reading Data from a File</h1>
@foreach (string dataLine in userData)
  foreach (string dataItem in dataLine.Split(','))
  {@dataItem <text>&nbsp;</text>}

  <br />
Run example »

Example explained

Server.MapPath finds the exact text file path.

File.ReadAllLines opens the text file and reads all lines from the file into an array.

For each dataItem in each dataline of the array the data is displayed.

Displaying Data from an Excel File

With Microsoft Excel, you can save a spreadsheet as a comma separated text file (.csv file). When you do so, each row in the spreadsheet is saved as a text line, and each data column is separated by a comma.

You can use the example above to read an Excel .csv file (just change the file name to the name of the Excel file).