Muss mal schnell was mitgeloggt werden, bietet sich z.B. der StreamWriter an.
using System.IO; ... string fileName = String.Format("log-{0}.txt", DateTime.Now.ToString("yyyy-MM-dd")); string dataRow = String.Format("{0}; {1}; {2}", DateTime.Now, var1, var2); StreamWriter myFile = new StreamWriter(Server.MapPath("~/App_Data/" + fileName), true); myFile.WriteLine(dataRow); myFile.Close();