如何在DataGridView的整數單元格中顯示字符串值？

Question

這段代碼從數據庫填充DataGridView 。 Volunteers.Status .Status在數據庫級別定義為Integer。

我想在Status列中顯示一個字符串而不是整數，但是當我嘗試將DataGridView1.Rows(row.Index).Cells(14).Value設置為字符串時，應用程序失敗。

Error: INACTIVE is not a valid value for Int32

碼

        SQL = "SELECT Volunteers.VolunteerID, Volunteers.NameVol AS Nombre, Volunteers.Surname AS Apellidos, Volunteers.email, Volunteers.Address AS Dirección, " & _
               "Volunteers.ID AS DNI, Volunteers.DateOfBirth AS Fecha, Volunteers.PostalCode AS CP, Volunteers.City AS Ciudad, Volunteers.Province AS Provincia, Volunteers.Phone AS Telefono, " & _
                "Volunteers.Studies AS Estudios, Volunteers.Vehicle AS Vehículo, Volunteers.Clothes AS Camiseta, Volunteers.Status AS Estado FROM Volunteers " & _
                "LEFT JOIN ActivityVolunteer ON Volunteers.VolunteerID = ActivityVolunteer.VolunteerID " & _
                "WHERE ActivityVolunteer.ActivityID = " & IDAct


        Dim ds1 As New DataSet

        Dim DA As New System.Data.OleDb.OleDbDataAdapter(SQL, SQLConnection)

        DA.Fill(ds1)

        DataGridView1.DataSource = ds1.Tables(0)


        For Each row As DataGridViewRow In DataGridView1.Rows

            Select Case DataGridView1.Rows(row.Index).Cells(14).Value
                Case 0
                    DataGridView1.Rows(row.Index).Cells(14).Value = "INACTIVE"
                Case 1
                    DataGridView1.Rows(row.Index).Cells(14).Value = "ACTIVE"
                Case 2
                    DataGridView1.Rows(row.Index).Cells(14).Value = "OTHER"

            End Select

        Next

更新：

然后我嘗試了一個技巧，使該列不可見，然后添加一個額外的列，其中包含基於隱藏列的值。

DataGridView1.Columns(14).Visible = False
DataGridView1.Columns.Add("Estado", "Estado")

    For Each row As DataGridViewRow In DataGridView1.Rows

        DataGridView1.Rows(row.Index).Cells(15).Value = Convert(row.Cells(14).Value)
    Next


Function Convert(ByVal e As Integer) As String
    Select Case e
        Case 0
            Return "INACTIVE"
        Case 1
            Return "ACTIVE"
        Case 2
            Return "OTHER"
    End Select
    Return String.Empty
End Function

此更改不會引發任何異常，但新列上的單元格為空。

我怎樣才能做到這一點？

Answer 1

這段代碼根本不應該編譯：

Function Convert(ByRef e As Integer) As Integer
    Select Case e
        Case 0
            e = "INACTIVE"
        Case 1
            e = "ACTIVE"
        Case 2
            e = "OTHER"
    End Select
 Return e
End Function

你傳遞一個整數byref ...（為什么？）...並試圖給它分配一個字符串值，然后返回它。 你要：

Function Convert(ByVal e As Integer) As String
    Select Case e
        Case 0
            return "INACTIVE"
        Case 1
            return "ACTIVE"
        Case 2
            return "OTHER"
    End Select
 return String.Empty
End Function

試試這個，看看你得到了什么。 我懷疑.CellFormatting事件可能不是你應該在這里處理的事情，但是給它一個機會。

Answer 2

我會更改sql語句以獲取您需要的字符串，如下所示

SELECT  Volunteers.VolunteerID,  StatusString =
      CASE Volunteers.Status   
         WHEN 0 THEN 'INACTIVE'
         WHEN 1 THEN 'ACTIVE'
         ELSE  'OTHER'
      END, ............
FROM ......