习惯的解决方法是存储Session的ID和当提交时ViewState中存储的SessionID相比较来防止用户刷新屏屏幕。前提你的程序中允许了自动回发，如果不是的话，就得在hidden field存储这个变量了。下面给出一个典型的例子。在Page_Load事件中你存储了第一次提交时的SessionID和一个时间戳。
protected System.Web.UI.WebControls.Button SubmitButton;

protected System.Web.UI.WebControls.Label RefreshID;     

private void Page_Load(object sender, System.EventArgs e)

{
     if (RefreshID.Text.Length == 0) 
    {
            RefreshID.Text = Session.SessionID+DateTime.Now.Ticks.ToString();
      }
}
 

private void Button1_Click(object sender, System.EventArgs e)

{
      string sesToken = (string) Session[FrameworkConst.SYNC_CONTROL_KEYWORD];      string pageToken = RefreshID.Text;
      if (sesToken != null && sesToken != pageToken)
      {
            Response.Write("The Refresh was performed after submit.");
     } 
      else
      {
            // do your processing here to avoid Refresh trap
            Response.Write("The processing is done here. Disabling submit
button so that user can not perform multiple submit.");
            Response.Write("But still user can peform Refresh on page.");
      }

      Session[FrameworkConst.SYNC_CONTROL_KEYWORD] =       Session.SessionID+DateTime.Now.Ticks.ToString();
      RefreshID.Text = sesToken;         
      SubmitButton.Enabled = false;