.net 时间的比较

string dbpath = Server.MapPath( " db/count.mdb " );
DbAccessdb = new DbAccess(dbpath);
#region "添加"
string url = Convert.ToString(Request.UrlReferrer);
string ip = Convert.ToString(Request.UserHostAddress);

// 判断
string sqlsel = string .Format( " selectcount(*)fromrecordwhereip='{0}' " ,ip);
int coun = Convert.ToInt32(db.GetDataTable(sqlsel).Rows[ 0 ][ 0 ].ToString());
bool add = false ;
if (coun > 0 )
{
sqlsel = string .Format( " select[date]fromrecordwhereip='{0}'orderbydatedesc " ,ip);
DateTimedt = Convert.ToDateTime(db.GetDataTable(sqlsel).Rows[ 0 ][ " date " ].ToString());
DateTimenow = DateTime.Now;
TimeSpants = now - dt;
double time = ts.TotalHours;
if (time > 2 )
{
add = true ;
}
else
{

}

}
else
{
add = true ;
}
// 添加
if (add)
{
string sqladd = string .Format( " insertintorecord(url,ip)values('{0}','{1}') " ,url,ip);

db.ReturnState(sqladd);
}

#endregion
#region 显示

DataSetds = new DataSet();
ds = db.GetDataSet( " selectcount(*)fromrecord " );

this .coun = Convert.ToString(ds.Tables[ 0 ].Rows[ 0 ][ 0 ]);
#endregion

DateTimenow = DateTime.Now;
DateTimeot = DateTime.Now.AddDays( 3 );
long al = now.Ticks;
long ot1 = ot.Ticks;
Response.Write(al);
Response.Write( " <br> " );
Response.Write(ot1);
Response.Write( " <br> " );
Response.Write(ot1 - al);
Response.Write( " <br> " );

Response.Write(((ot1 - al) / 10000 / 1000 ) / ( 60 * 60 * 24 )); // 相差几天