朋友，我有在vb.net以下的代码:

 Private Sub btnSetGrade_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSetGrade.Click

        Dim CollIndex As Integer = 0, TempID As Integer = 0, SaveID As Integer = 0

        Dim ColName As String = "", TempIDTotal As String = "", QryGetTot As String = ""

        cmdExecute("delete from tbTestHeading")

        cmdExecute("insert into   tbTestHeading (tempID) values (1)")

 

        '==================Get Subject Name of Current Session=================================

        Dim dsSession As DataSet = DirectCast(cmdGetData("SELECT DISTINCT [session],class_id FROM  testmaster  WHERE   (Srno IN (SELECT srno  FROM  testdetail WHERE (stcode =" & txtStudentCode.Text & ") ORDER BY srno)) order by [session]"), DataSet)

        Dim sessionID As String = "", classID As String = ""

        For i = 0 To dsSession.Tables(0).Rows.Count - 1

            sessionID = sessionID & "'" & dsSession.Tables(0).Rows(i)(0) & "',"

            classID = classID & dsSession.Tables(0).Rows(i)(1) & ","

        Next

        sessionID = sessionID.Substring(0, sessionID.Length - 1)

        classID = classID.Substring(0, classID.Length - 1)

 

        '============Get Test names and Insert in table====================

        Dim dsTestName As DataSet = DirectCast(cmdGetData("SELECT DISTINCT testmaster.test, testgrade.testOrder FROM  (testmaster INNER JOIN  testgrade ON testmaster.test = testgrade.testName) WHERE  (testmaster.class_id IN (" & classID & ")) AND (testmaster.[session] IN (" & sessionID & ")) ORDER BY testgrade.testOrder"), DataSet)

        If dsTestName.Tables(0).Rows.Count > 0 Then

            For iTN = 0 To dsTestName.Tables(0).Rows.Count - 1

                CollIndex = CollIndex + 1

                cmdExecute("update tbTestHeading set R" & CollIndex & "='" & dsTestName.Tables(0).Rows(iTN)("test") & "' where tempID=1")

                QryGetTot = QryGetTot & "R" & CollIndex & ","

            Next

            QryGetTot = "R" & CollIndex + 2 & "," & QryGetTot

        End If

        '=============================End Test Name=============================================



        '======================Get Max Temp ID============================================

        Dim MaxID As Integer = Convert.ToInt32(getMaxID("tempID", "tbTestHeading"))

 



        For iSn = 0 To dsSession.Tables(0).Rows.Count - 1

            MaxID = MaxID + 1

            '==========Get year on based of Session and save===================

            Dim dsYear As DataSet = DirectCast(cmdGetData("SELECT startdate,enddate  FROM SessionMaster where srno=" & dsSession.Tables(0).Rows(iSn)("session")), DataSet)

            Dim StartYear = Year(dsYear.Tables(0).Rows(0)("startdate"))

            Dim EndYear = Year(dsYear.Tables(0).Rows(0)("enddate"))

            Dim Session = StartYear & "-" & EndYear

            cmdExecute("insert into   tbTestHeading (tempID,sessionName) values (" & MaxID & ",'" & Session & "')")

            SaveID = MaxID

            TempIDTotal = TempIDTotal & MaxID & ","

            '=====================End Year========================================



            '===================Get Subject name of Current session========================

            Dim dsSubjectName As DataSet = DirectCast(cmdGetData("SELECT DISTINCT Subject_master.shortName FROM  ((testdetail INNER JOIN  testmaster ON testdetail.srno = testmaster.Srno) INNER JOIN Subject_master ON testmaster.sub_id = Subject_master.srno) WHERE (testdetail.stcode =" & txtStudentCode.Text & ") AND (testmaster.[session] = '" & dsSession.Tables(0).Rows(iSn)("session") & "') "), DataSet)

            For iSubN = 0 To dsSubjectName.Tables(0).Rows.Count - 1

                MaxID = MaxID + 1

                cmdExecute("insert into   tbTestHeading (tempID,subjectName) values (" & MaxID & ",'" & dsSubjectName.Tables(0).Rows(iSubN)("shortName") & "')")

 

            Next 'Subject Name For End

            '======================End Subject Name====================



            '===========Get Marks of Student in Particular Session====================

            Dim dsMarks As DataSet = DirectCast(cmdGetData("SELECT testdetail.marks, testmaster.test, Subject_master.shortName, testmaster.class_id, testmaster.[section], testdetail.[max] FROM (((testdetail INNER JOIN  testmaster ON testdetail.srno = testmaster.Srno) INNER JOIN Subject_master ON testmaster.sub_id = Subject_master.srno) INNER JOIN testgrade ON testmaster.test = testgrade.testName) WHERE (testdetail.stcode = " & txtStudentCode.Text & ") AND (testmaster.[session] = '" & dsSession.Tables(0).Rows(iSn)("session") & "') ORDER BY testgrade.testOrder, Subject_master.srno "), DataSet)

            Dim MaxMarks As Integer = 0

 

            '===========Get Maximum marks =======================================

            Dim dsMax As DataSet = DirectCast(cmdGetData("SELECT DISTINCT testmaster.test, testmaster.[max] FROM  (testmaster INNER JOIN  testdetail ON testmaster.Srno = testdetail.srno) WHERE  (testdetail.stcode =" & txtStudentCode.Text & ") AND (testmaster.[session] = '" & dsSession.Tables(0).Rows(iSn)("session") & "') AND (testmaster.[section] = '" & dsMarks.Tables(0).Rows(0)("section") & "') AND (testmaster.class_id =" & dsMarks.Tables(0).Rows(0)("class_id") & ")"), DataSet)

            For iMax = 0 To dsMax.Tables(0).Rows.Count - 1

                Try

                    MaxMarks = MaxMarks + dsMax.Tables(0).Rows(iMax)("max")

                Catch ex As Exception

                    MaxMarks = 0

                End Try

            Next

            '=============End Maximum Marks=============================================



            For iM = 0 To dsMarks.Tables(0).Rows.Count - 1

 

                '============================Get Column Name===================================

                Dim dsColumnName As DataSet = DirectCast(cmdGetData("select * from tbTestHeading where tempID=1"), DataSet)

                For iCN = 0 To dsColumnName.Tables(0).Columns.Count - 1

                    If Convert.ToString(dsMarks.Tables(0).Rows(iM)("test")) = Convert.ToString(dsColumnName.Tables(0).Rows(0)(iCN)) Then

                        ColName = dsColumnName.Tables(0).Columns(iCN).ColumnName

                        Exit For

                    End If

                Next 'Column Name For End



                '================Change Here==========================

                '================Get Grade according Marks==============

                Dim Grade As String = ""

                Dim gradeMarks As Decimal = 0

                If Convert.ToInt32(dsMarks.Tables(0).Rows(iM)("marks")) <> 0 Then

                    gradeMarks = Convert.ToInt32(dsMarks.Tables(0).Rows(iM)("marks")) * 100 / Convert.ToInt32(Convert.ToInt32(dsMarks.Tables(0).Rows(iM)("max")))

 

                    Dim dsGrade As DataSet = DirectCast(cmdGetData("select * from SessionGrade"), DataSet)

                    For iG = 0 To dsGrade.Tables(0).Rows.Count - 1

                        If gradeMarks >= dsGrade.Tables(0).Rows(iG)("mf") And gradeMarks <= dsGrade.Tables(0).Rows(iG)("mt") Then

                            Grade = "\" & dsGrade.Tables(0).Rows(iG)("grade")

                            Exit For

                        End If

                    Next

                Else

                    Grade = ""

                End If

                '==============End Grade============================

                '================End Change=============================



                '================Set Marks of Current subject in curretn Test in Current Session===================



                '=============== Change here =====================

                Dim qry As String = "update tbTestHeading set " & ColName & "='" & dsMarks.Tables(0).Rows(iM)("marks") & Grade & "' where subjectName='" & dsMarks.Tables(0).Rows(iM)("shortName") & "' and tempID>" & SaveID

                '================End Change=========================

                cmdExecute(qry)

                cmdExecute("update tbTestHeading set R" & CollIndex + 2 & "='" & MaxMarks & "' where subjectName='" & dsMarks.Tables(0).Rows(iM)("shortName") & "' and tempID>" & SaveID)

 



            Next 'Marks For End



        Next 'Session For End



        '==========================Total=================================================

        CollIndex = CollIndex + 1

        cmdExecute("update tbTestHeading set R" & CollIndex & "='Total' where tempID=1")

        cmdExecute("update tbTestHeading set R" & CollIndex + 1 & "='Percntage' where tempID=1")

        TempIDTotal = TempIDTotal.Substring(0, TempIDTotal.Length - 1)

        QryGetTot = QryGetTot.Substring(0, QryGetTot.Length - 1)

        Dim qryTot As String = "select tempID," & QryGetTot & " FROM  tbTestHeading WHERE  (NOT (tempID IN (1," & TempIDTotal & ")))"

        Dim dsTotal As DataSet = DirectCast(cmdGetData(qryTot), DataSet)

        For iTR = 0 To dsTotal.Tables(0).Rows.Count - 1

            Dim TotMarks As Decimal = 0

            For iTC = 2 To dsTotal.Tables(0).Columns.Count - 1

 

                '===================== Change here =======================

                Dim MarksR As String = Convert.ToString(dsTotal.Tables(0).Rows(iTR)(iTC))

                If MarksR <> "" Then

                    Dim a = MarksR.IndexOf("\")

                    MarksR = MarksR.Substring(0, a)

 

                    Dim marks As Decimal = 0

                    Try

                        marks = Convert.ToDecimal(MarksR)

                    Catch ex As Exception

                        marks = 0

                    End Try

 

                    TotMarks = TotMarks + marks

                End If

                '=================End Change==============================

            Next

 



            '==============Set Total Marks===================

            cmdExecute("update tbTestHeading set R" & CollIndex & "='" & TotMarks & "' where tempID=" & dsTotal.Tables(0).Rows(iTR)(0))

 

            '===================Set Average======================================

            Dim Avg As Decimal = TotMarks / Convert.ToInt32(dsTotal.Tables(0).Rows(iTR)(1)) * 100

            Avg = Math.Round(Avg, 2)

            cmdExecute("update tbTestHeading set R" & CollIndex + 1 & "='" & Avg & "' where tempID=" & dsTotal.Tables(0).Rows(iTR)(0))

        Next

        MsgBox("Success")

    End Sub

问题是，它正在运行21秒。有人告诉我，我怎么能提高它的性能| Parveen Rathi