How can I create a temp file with a specific extension with .NET?

Question

I need to generate a unique temporary file with a .csv extension.

What I do right now is

string filename = System.IO.Path.GetTempFileName().Replace(         


        

Answer 1

This is a simple but effective way to generate incremental filenames. It will look in the current directly (you can easily point that somewhere else) and search for files with the base YourApplicationName*.txt (again you can easily change that). It will start at 0000 so that the first file name will be YourApplicationName0000.txt. if for some reason there are file names with junk between (meaning not numbers) the left and right parts, those files will be ignored by virtue of the tryparse call.

    public static string CreateNewOutPutFile()
    {
        const string RemoveLeft = "YourApplicationName";
        const string RemoveRight = ".txt";
        const string searchString = RemoveLeft + "*" + RemoveRight;
        const string numberSpecifier = "0000";

        int maxTempNdx = -1;

        string fileName;
        string [] Files = Directory.GetFiles(Directory.GetCurrentDirectory(), searchString);
        foreach( string file in Files)
        {
            fileName = Path.GetFileName(file);
            string stripped = fileName.Remove(fileName.Length - RemoveRight.Length, RemoveRight.Length).Remove(0, RemoveLeft.Length);
            if( int.TryParse(stripped,out int current) )
            {
                if (current > maxTempNdx)
                    maxTempNdx = current;
            }
        }
        maxTempNdx++;
        fileName = RemoveLeft + maxTempNdx.ToString(numberSpecifier) + RemoveRight;
        File.CreateText(fileName); // optional
        return fileName;
    }