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How to: Read a Text File One Line at a Time (Visual C#)

This example reads the contents of a text file, one line at a time, into a string using the ReadLine method of the StreamReader class. Each text line is stored into the string line and displayed on the screen.

int counter = 0;
string line;

// Read the file and display it line by line.
System.IO.StreamReader file = 
    new System.IO.StreamReader(@"c:\test.txt");
while((line = file.ReadLine()) != null)
    System.Console.WriteLine (line);

System.Console.WriteLine("There were {0} lines.", counter);
// Suspend the screen.

Copy the code and paste it into the Main method of a console application.

Replace "c:\test.txt" with the actual file name.

The following conditions may cause an exception:

  • The file may not exist.

Do not make decisions about the contents of the file based on the name of the file. For example, the file myFile.cs may not be a C# source file.