Question

我试图通过按钮选择所有行，或者使用ctrl + click选择不同的行。但即使我选择了多行，它也只检查第一行。然后它再次重新读取它而不是去下一行。我不确定在哪里放置多选代码。

最初，您只需要点击一行，然后检查条件是否满足。但是，如果满足条件，则要求您可以执行多个并检查每一行。

这是我的代码：

    Private Sub DataGridView1_SelectionChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DataGridView1.SelectionChanged
    Dim i As Integer
    i = DataGridView1.CurrentRow.Index
    _subjectno = DataGridView1.Item(0, i).Value
    _title = DataGridView1.Item(1, i).Value
    _unit = DataGridView1.Item(2, i).Value
    _pre = DataGridView1.Item(3, i).Value
End Sub

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
    DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
    DataGridView1.MultiSelect = True
    DataGridView1.SelectAll()
End Sub



Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
    Dim selectedItems As DataGridViewSelectedRowCollection = DataGridView1.SelectedRows
    For Each selectedItem As DataGridViewRow In selectedItems
        add()
    Next
End Sub



Sub add()
    Try

        If IS_EMPTY(txtSno) = True Then Return

        cm = New MySqlCommand("select * from tblenroll where subjectnumber like '" & _subjectno & "' and remarks <> 'Failed' and studentno like '" & txtSno.Text & "'", cn)
        dr = cm.ExecuteReader
        dr.Read()
        If dr.HasRows Then
            MsgBox("Subject is already taken.", vbExclamation)
            dr.Close()
            Return
        Else
            dr.Close()
        End If

        If _pre = "NONE" Or _pre = "2ND YR STANDING" Or _pre = "3RD YR STANDING" Or _pre = "4TH YR STANDING" Or _pre = "5TH YR STANDING" Then

            cm = New MySqlCommand("insert into tblenroll (studentno, subjectnumber, ay,semester,dateenrolled, curriculum) values ('" & txtSno.Text & "','" & _subjectno & "','" & txtAY.Text & "','" & txtSem.Text & "','" & Now & "','" & txtCurriculum.Text & "')", cn)
            cm.ExecuteNonQuery()
            MsgBox(_subjectno & " successfully added.", vbInformation)
            LoadEnrolled()
        Else

            cm = New MySqlCommand("select * from tblenroll where studentno like '" & txtSno.Text & "' and subjectnumber like '" & _subjectno & "' and ay like '" & txtAY.Text & "'", cn)
            dr = cm.ExecuteReader
            dr.Read()
            If dr.HasRows Then
                MsgBox("Subject is already taken.", vbExclamation)
                dr.Close()
                Return
            Else
                dr.Close()
            End If


            Dim strok As Boolean = False

            Dim strArr() As String
            Dim count As Integer
            Dim strpre As String = _pre
            strArr = strpre.Split(", ")
            For count = 0 To strArr.Length - 1
                cm = New MySqlCommand("select * from tblenroll as e inner join tblsubject as s on e.subjectnumber = s.subjectno where s.subjectno like '%" & Trim(strArr(count)) & "%' and studentno like '" & txtSno.Text & "' and remarks like 'Passed'", cn)
                dr = cm.ExecuteReader
                dr.Read()
                If dr.HasRows Then
                    dr.Close()
                    strok = True
                Else
                    MsgBox("Unable to enroll this subject. Pre-requisite " & strArr(count) & ".", vbExclamation)
                    dr.Close()
                    Return
                End If
            Next


            If strok = True Then
                cm = New MySqlCommand("insert into tblenroll (studentno, subjectnumber, ay, semester, dateenrolled, curriculum) values ('" & txtSno.Text & "','" & _subjectno & "','" & txtAY.Text & "','" & txtSem.Text & "','" & Now & "','" & txtCurriculum.Text & "')", cn)
                cm.ExecuteNonQuery()
                MsgBox(_subjectno & " successfully added.", vbInformation)
                LoadEnrolled()
            End If
        End If


    Catch ex As Exception
        MsgBox(ex.Message, vbCritical)
    End Try

End Sub

非常感谢你！

Answer 1

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
    For Each selectedItem As DataGridViewRow In DataGridView1.SelectedRows
        _subjectno = selectedItem.Cells(0).Value
        _title = selectedItem.Cells(1).Value
        _unit = selectedItem.Cells(2).Value
        _pre = selectedItem.Cells(3).Value
        add()
    Next
End Sub

DataGridView选择多行，检查每一行

1 个答案: