frmgrademan.vb

代码：是由本人自主开发完成的

            stugdbset = Nothing
            stugdbset = MyGrade.GetStuGrade(CurMar.MarjoyID, Trim(CombTestYear.Text) & Trim(CombTesttime.Text))
            If Not stugdbset Is Nothing Then
                DGStudent.DataSource = stugdbset.Tables(0).DefaultView
            Else
                DGStudent.DataSource = Nothing
            End If
        End If
        DGStudent.CaptionText = "学生信息"
        DGStuGradeDetials.CaptionText = "学生成绩明细"
        dsstugraddeta = Nothing
        DGStuGradeDetials.DataSource = Nothing
        clearfrom()
    End Sub

    Private Sub RDBDetails_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RDBDetails.CheckedChanged
        If RDBModify.Checked = True Then
            GetDataSet()
            BindGradesGrid()
        Else
            stugdbset = Nothing
            stugdbset = MyGrade.GetStuGrade(CurMar.MarjoyID, Trim(CombTestYear.Text) & Trim(CombTesttime.Text))
            DGStudent.ReadOnly = True
            If Not stugdbset Is Nothing Then
                DGStudent.DataSource = stugdbset.Tables(0).DefaultView
            Else
                DGStudent.DataSource = Nothing
            End If
            DGStudent.CaptionText = "学生信息"
        End If
        DGStuGradeDetials.CaptionText = "学生成绩明细"
        dsstugraddeta = Nothing
        DGStuGradeDetials.DataSource = Nothing
        clearfrom()
    End Sub

    Private Sub DGStudent_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DGStudent.CurrentCellChanged
        If DGStudent.CurrentRowIndex < 0 Then
            Exit Sub
        End If
        If DGStudent.Item(DGStudent.CurrentRowIndex, 0) Is Nothing Then
            Exit Sub
        End If
        If RDBDetails.Checked Then
            txtStuName.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 1)
            txtStuID.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 2)
            CombSexy.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 3)
            txtDepartment.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 4)
            txtMarjoy.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 5)
            txtGrade.Text = DGStudent.Item(DGStudent.CurrentRowIndex, 6)
            MyStu.GetStuInfo(txtStuID.Text)
            CurStu.Equal(MyStu)
            CurGrade.GetInfo(DGStudent.Item(DGStudent.CurrentRowIndex, 8))

            dsstugraddeta = Nothing
            dsstugraddeta = MyGrade.GetInfoByStuID(CurGrade.StudentID)
            If Not dsstugraddeta Is Nothing Then
                DGStuGradeDetials.CaptionText = "学生[" & CurStu.StudentName & "]共参加:" & _
                       dsstugraddeta.Tables(0).Rows.Count.ToString & "次考试"
                DGStuGradeDetials.ReadOnly = True
                DGStuGradeDetials.DataSource = dsstugraddeta.Tables(0).DefaultView
            Else
                DGStuGradeDetials.CaptionText = "学生[" & CurStu.StudentName & "]共参加:0次考试"
                DGStuGradeDetials.DataSource = Nothing
                DGStuGradeDetials.ReadOnly = True
            End If
        Else
            Dim tmpds As DataSet
            tmpds = MyGrade.GetStuInfo(DGStudent.Item(DGStudent.CurrentRowIndex, 1), DGStudent.Item(DGStudent.CurrentRowIndex, 3))
            If Not tmpds Is Nothing Then
                txtStuName.Text = tmpds.Tables(0).Rows(0).Item(1)
                txtStuID.Text = tmpds.Tables(0).Rows(0).Item(2)
                CombSexy.Text = tmpds.Tables(0).Rows(0).Item(3)
                txtDepartment.Text = tmpds.Tables(0).Rows(0).Item(4)
                txtMarjoy.Text = tmpds.Tables(0).Rows(0).Item(5)
                txtGrade.Text = tmpds.Tables(0).Rows(0).Item(6)
                DGStudent.CaptionText = "学生信息--当前编辑学生[" & txtStuName.Text & "(" & txtStuID.Text & ")]"
            End If
        End If
    End Sub
    Public Function CreateDataSet() As DataSet
        Dim dsgrades As DataSet
        ' Attempt to connect to the local SQL server instance, and a local
        ' MSDE installation (with Northwind).  
        Dim IsConnecting As Boolean = True
        While IsConnecting
            Try
                ' The SqlConnection class allows you to communicate with SQL Server.
                ' The constructor accepts a connection string as an argument.  This
                ' connection string uses Integrated Security, which means that you 
                ' must have a login in SQL Server, or be part of the Administrators
                ' group for this to work.
                Dim scnnNW As New OleDbConnection(ConnectStr)

                Dim strSQL As String = _
                    "SELECT * FROM Grades"

                ' A SqlCommand object is used to execute the SQL commands.
                Dim scmd As New OleDbCommand(strSQL, scnnNW)

                ' A SqlDataAdapter uses the SqlCommand object to fill a DataSet.
                sdastugrades = New OleDbDataAdapter(scmd)

                ' A SqlCommandBuilder automatically generates the SQL commands needed
                ' to update the database later.
                Dim scb As New OleDbCommandBuilder(sdastugrades)


                ' Create a new DataSet and fill its first DataTable.
                dsgrades = New DataSet
                sdastugrades.Fill(dsgrades, "Grades")

                IsConnecting = False

            Catch exp As Exception
                MsgBox("连接数据库失败,请重新操作!", MsgBoxStyle.Exclamation, "大学语文考试系统V2.0")
                Exit Function
            End Try
        End While
        Return dsgrades

    End Function
    Public Sub UpdateDataSet(ByVal inDS As DataSet)

        ' If the DataSet that was passed in is Nothing, exit this subrouting.
        If inDS Is Nothing Then
            Exit Sub
        End If

        Try
            ' First verify that the data adapters have been created, and call
            '   the CreateDataSet to build them if necessary.
            If sdastugrades Is Nothing Then
                CreateDataSet()
            End If

            ' Try to Update the DataSet. It is critical that everything is done
            '   in the proper sequence, unless you turn off the EnforceConstraints property.

            ' So there are two ways of updating the data. 
            ' The first is shutting off EnforceConstraints
            'inDS.EnforceConstraints = False
            sdastugrades.Update(inDS, "Grades")


            '' Changes can be made in any order
            If Not inDS.GetChanges(DataRowState.Modified) Is Nothing Then
                sdastugrades.Update(inDS.GetChanges(DataRowState.Modified), "Grades")
            End If

            If Not inDS.GetChanges(DataRowState.Deleted) Is Nothing Then
                sdastugrades.Update(inDS.GetChanges(DataRowState.Modified), "Grades")
            End If

            sdastugrades = Nothing
        Catch exc As Exception
            sdastugrades = Nothing
            ' Alert the front end that an error occurred.
            MsgBox("连接数据库失败,请重新操作!", MsgBoxStyle.Exclamation, "大学语文考试系统V2.0")
            Exit Sub
        End Try
    End Sub

    Private Sub cmdFlash_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdFlash.Click
        MyDep.Initials()
        CurDep.Initials()
        MyMar.Initials()
        CurMar.Initials()
        MyStu.Initials()
        CurStu.Initials()
        MyGrade.Initials()
        CurGrade.Initials()
        MyDep.LoadDepNodesToTV(TvDep)
        clearfrom()
        RDBDetails.Checked = True
        stugdbset = Nothing
        sdastugrades = Nothing
        With DGStudent
            .CaptionText = "学生成绩"
            .DataSource = Nothing
        End With
        LbMarjoy.Items.Clear()
        DGStuGradeDetials.CaptionText = "学生成绩明细"
        dsstugraddeta = Nothing
        DGStuGradeDetials.DataSource = Nothing
    End Sub

    Private Sub Label11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label11.Click
        If Trim(txtQuery.Text) = "" Then
            Exit Sub
        End If
        Dim tmpdbset As DataSet = MyGrade.QueryStuGrades(txtQuery.Text)
        RDBDetails.Checked = True

        If Not tmpdbset Is Nothing Then
            With DGStudent
                .CaptionText = "学生信息"
                .ReadOnly = True
                .DataSource = tmpdbset.Tables(0).DefaultView
            End With
        Else
            With DGStudent
                .CaptionText = "学生信息"
                .ReadOnly = True
                .DataSource = Nothing
            End With
        End If
        clearfrom()
        DGStuGradeDetials.CaptionText = "学生成绩明细"
        dsstugraddeta = Nothing
        DGStuGradeDetials.DataSource = Nothing
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If RDBModify.Checked = True Then
            Dim i As Integer
            If DGStudent.CurrentRowIndex >= 0 Then
                i = DGStudent.CurrentRowIndex
                If MsgBox("您是否真的要删除该学生的本次考试？", MsgBoxStyle.Question + MsgBoxStyle.YesNo, "大学语文考试系统V2.0") = MsgBoxResult.Yes Then
                    dvstugrades.Delete(i)
                    UpdateDataSet(dsstugrades.GetChanges())
                    GetDataSet()
                    BindGradesGrid()
                End If

            End If
        End If
    End Sub


  

    Private Sub frmGradeMan_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
        MyDep.Initials()
        CurDep.Initials()
        MyMar.Initials()
        CurMar.Initials()
        MyStu.Initials()
        CurStu.Initials()
        MyGrade.Initials()
        CurGrade.Initials()
        stugdbset = Nothing
    End Sub

    Private Sub frmGradeMan_Deactivate(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Deactivate
        MyDep.Initials()
        CurDep.Initials()
        MyMar.Initials()
        CurMar.Initials()
        MyStu.Initials()
        CurStu.Initials()
        MyGrade.Initials()
        CurGrade.Initials()
        GbMarjoy.Text = "专业信息--当前专业[]"
        GbDepartment.Text = "院系信息--当前院系:[]"
        With DGStudent
            .CaptionText = "学生成绩"
            .DataSource = Nothing
        End With
        clearfrom()
        DGStuGradeDetials.CaptionText = "学生成绩明细"
        dsstugraddeta = Nothing
        DGStuGradeDetials.DataSource = Nothing
        RDBDetails.Checked = True
        stugdbset = Nothing
    End Sub

 
End Class