Writing data into CSV file in C#

Question

I am trying to write into a csv file row by row using C# language. Here is my function

string first = reader[0].ToString();
string second=image.         


        

Answer 1

I would highly recommend you to go the more tedious route. Especially if your file size is large.

using(var w = new StreamWriter(path))
{
    for( /* your loop */)
    {
        var first = yourFnToGetFirst();
        var second = yourFnToGetSecond();
        var line = string.Format("{0},{1}", first, second);
        w.WriteLine(line);
        w.Flush();
    }
}

File.AppendAllText() opens a new file, writes the content and then closes the file. Opening files is a much resource-heavy operation, than writing data into open stream. Opening\closing a file inside a loop will cause performance drop.

The approach suggested by Johan solves that problem by storing all the output in memory and then writing it once. However (in case of big files) you program will consume a large amount of RAM and even crash with OutOfMemoryException

Another advantage of my solution is that you can implement pausing\resuming by saving current position in input data.

upd. Placed using in the right place