Reading and Parsing Files in .NET - Performance For Hire

Question

I want the most performat way to read and parse a file.

Is it possible to read a file in .NET, but not load the entire file into memory? i.e. just load the file line by line as I parse the content of each row?

Does XmlTextReader load the entire file into memory or does it stream the file into memory as it reads the file?

Answer 1

You could use the ReadLine method of StreamReader Class:

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)
{
   Console.WriteLine (line);
}

file.Close();

For XML files I would go with XMLTextReader. See this article on Dr. Dobb's Journal:

"Parsing XML Files in .NET Using C#: Five different parsing techniques are available in .NET, and each has its own advantages"