You need to create a file that will be placed in the user -specific temporary directory and will have a unique name so that it won't collide with temporary files generated by other programs.
Use the static GetTempFileName method of the System.IO. Path class, which returns a path made up of the user's temporary directory and a randomly generated file name.
There are a number of approaches to generating temporary files. In simple cases, you might just create a file in the application directory, possibly using a GUID or a timestamp in conjunction with a random value as the file name. However, the Path class provides a helper method that can save you some work. It creates a file with a unique file name in the current user's temporary directory. This might be a path like c:\documents and settings\username\local settings\temp\tmpac9.tmp.
using System; using System.IO; public class TemporaryFile { private static void Main() { string tempFile = Path.GetTempFileName(); Console.WriteLine("Using " + tempFile); FileStream fs = new FileStream(tempFile, FileMode.Open); // (Write some data.) fs.Close(); // Now delete the file. File.Delete(tempFile); Console.ReadLine(); } }