网站发布后在IIS上定时执行任务

string filename = (DateTime.Now.ToString() + DateTime.Now.Millisecond.ToString()).Replace("/", "").Replace(":", "").Replace(" ", "") + ".txt";
// string file = "~/img/" + filename;
string file = @"C:\Users\Administrator\Documents\Visual Studio 2013\WebSites\testasax\img" + filename;
string content = "写入内容！";
if (System.IO.File.Exists(file) == true)
{
// MessageBox.Show("存在此文件!");
}
else
{
System.IO.FileStream myFs = new System.IO.FileStream(file, System.IO.FileMode.Create);
System.IO.StreamWriter mySw = new System.IO.StreamWriter(myFs);
mySw.Write(content);
mySw.Close();
myFs.Close();

}