Reading and Writing Files in C#

string writeFilePath = @"C:\PlugIn\Dimuthu.txt";
string readFilePath = @"C:\PlugIn\Nuwan.txt";

/// Used to read from one file and write to an another file using
/// Byte Array.
FileStream openFile = new FileStream(readFilePath, FileMode.Open, FileAccess.ReadWrite);
FileStream writeFile = new FileStream(writeFilePath, FileMode.Create, FileAccess.Write);
BufferedStream outFile = new BufferedStream(writeFile);

int count;
byte[] buffer;
buffer = new byte[4096];
while ((count = openFile.Read(buffer, 0, buffer.Length)) > 0)
{
outFile.Write(buffer, 0, count);
outFile.Flush();
}

/// Used to write a Large File for 20 seconds.
/// This will be helpful for performance testing.
FileStream fileStream = new FileStream(writeFilePath, FileMode.Create, FileAccess.Write);
DateTime end = DateTime.Now.AddSeconds(20.0);
StreamWriter file = new StreamWriter(fileStream);

while (DateTime.Now < end)
{
file.WriteLine(count);
file.Flush();
Console.WriteLine(count);
count++;
}
file.Close();


/// Used to create a zero byte text file.
string folderPath = @"C:\Test";
Directory.CreateDirectory(folderPath);
File.Create(folderPath + "\\Game.txt", 1);