ASP.NET Web Pages - Files
This chapter introduces knowledge about using text files.
Using Text Files
In previous chapters, we have learned that web data is stored in databases.
You can also store site data in text files.
Text files used to store data are commonly referred to as flat files. Common text file formats are .txt, .xml, and .csv (comma-separated values).
In this chapter, you will learn:
- How to read and display data from text files
Manually Adding a Text File
In the following example, you will need a text file.
On your website, if there is no App_Data folder, create one. Inside the App_Data folder, create a file named Persons.txt.
Add the following content to the file:
Persons.txt
Displaying Data from a Text File
The following example demonstrates how to display data from a text file:
Example
@{
var dataFile = Server.MapPath("~/App_Data/Persons.txt");
Array userData = File.ReadAllLines(dataFile);
}
<!DOCTYPE html>
@foreach (string dataLine in userData) {
foreach (string dataItem in dataLine.Split(',')) {
@dataItem <text> </text>
}
}
Example Explanation
Use Server.MapPath to find the exact path of the text file.
Use File.ReadAllLines to open the text file and read all lines into an array.
Each data line in the array is displayed, with data items separated by commas.
Displaying Data from an Excel File
Using Microsoft Excel, you can save a spreadsheet as a comma-separated text file (.csv file). Each row in the spreadsheet is saved as a text line, and each data column is separated by a comma.
You can use the above example to read an Excel .csv file (just change the file name to the corresponding Excel file name).