DataGridView выбрать несколько строк, проверить каждую строку

Question

Я пытаюсь выбрать все строки кнопкой или выбрать разные строки с помощью Ctrl + клик. Но даже если я выбрал несколько строк, он проверяет только первую строку. Затем он перечитывает его снова, а не переходит к следующему ряду. Я не уверен, где разместить код мультиселектора.

Первоначально вы должны просто щелкнуть строку, а затем проверить, выполнены ли условия. Однако было запрошено, что вы можете сделать несколько и проверить каждую строку, если условие выполнено.

Вот мой код:

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 

Спасибо так много!

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