如何在vb.net中的datagridview中檢查不可為空的列s

Question

我有一個數據網格視圖，如果特定的列不為null，我想工作一些代碼。所以我給出了這樣的代碼：

For i As Integer = 0 To gv.RowCount - 2
            If gv.Rows(i).Cells(1).Value IsNot System.DBNull.Value Then
                Dim cnt As Integer = RecordPresent("CompanyMaster_tbl", "CompanyName", gv.Rows(i).Cells(1).Value)
                If cnt = 0 Then
                    sqlInsertT1 = "Insert Into CompanyMaster_tbl(CompanyName) Values ('" + gv.Rows(i).Cells(1).Value + "')"
                    Exetransaction(sqlInsertT1)
                    Ccid = RecordID("Cid", "CompanyMaster_tbl", "CompanyName", gv.Rows(i).Cells(1).Value)
                Else
                    Ccid = RecordID("Cid", "CompanyMaster_tbl", "CompanyName", gv.Rows(i).Cells(1).Value)
                End If
            End If



            sqlInsertT2 = "Insert Into DepartmentMaster_tbl(dtname,dtphone,dtEmail,Cid) Values ('" + gv.Rows(i).Cells(3).Value + "','" + gv.Rows(i).Cells(4).Value + "','" + gv.Rows(i).Cells(5).Value + "'," & Ccid & ");"
            Exetransaction(sqlInsertT2)
        Next

但是有時如果條件允許執行此條件內編寫的代碼，則此特定列也為null 如果gv.Rows（i）.Cells（1）.Value IsNot System.DBNull.Value然后

Answer 1

請嘗試使用IsDBNull(Expression)代替，並檢查其是否為空字符串。 像這樣 ：

 If Not IsDBNull(gv.Rows(i).Cells(1).Value) AndAlso gv.Rows(i).Cells(1).Value.ToString.Length <> 0 Then
 ' YourCode
 End If