我有一個基於DataGridView的應用程序出現問題。將記錄添加到網格後,如果我隨後嘗試更新或刪除新記錄,則會收到以下相應錯誤。 併發衝突:UpdateCommand影響了預期的1條記錄中的0個。 併發衝突:DeleteCommand影響了預期的1條記錄中的0個。 在RowValidated事件中強制保存數據集。DataGridView - 更新或刪除新記錄時的併發問題
Private Sub uxGrid_RowValidated(sender As Object, e As DataGridViewCellEventArgs) Handles uxGrid.RowValidated
If IsDGVRowDirty(sender, e.RowIndex) Then
Save()
End If
End Sub
Private Sub Save()
Const procName As String = "Save"
Try
_Logger.SendLog(Me.Name & "." & procName & " - Saving alarm definition data.", NLog.LogLevel.Trace)
_myAlarmDefinitionMngr.Save(_myDataSet)
_Logger.SendLog(Me.Name & "." & procName & " - Alarm definition data has been saved.", NLog.LogLevel.Trace)
Catch ex As Exception
MsgBox("There was a problem whilst saving your changes. Please reload the form and try again. " & vbCrLf & vbCrLf & ex.Message, MsgBoxStyle.Critical)
_Logger.SendLog(ex.Message & ". Thrown in module " & Me.Name.ToString & "." & procName, NLog.LogLevel.Error, ex)
Finally
End Try
End Sub
的客戶端應用程序坐落在一個相對簡單的三層建築設計交談到Oracle 11的後端的上方,在這種情況下,包括的元素AlarmDefinitionManager.vb,AlarmDefinitionDB.vb,AlarmDefinition.vb。
Public Function Save(ByVal myDataSet As DataSet) As Integer
Dim myOda As OracleDataAdapter
Dim myConnection As New OracleConnection
Dim myCommand As OracleCommand = Nothing
Dim myDataAdapter As OracleDataAdapter
Dim myBuilder As OracleCommandBuilder
Dim sqlStatement As String
myConnection = New OracleConnection
myConnection.ConnectionString = _connectStr
sqlStatement = "SELECT ID, LEGENDID, STATUSID, STATUSTYPEID, DIGITALSET FROM P_TBL_ALARMDEF"
If myDataSet.HasChanges Then
Try
myOda = New OracleDataAdapter(sqlStatement, myConnection)
myBuilder = New OracleCommandBuilder(myOda)
myOda.SelectCommand = New OracleCommand(sqlStatement, myConnection)
myOda.Update(myDataSet, "AlarmDefinition")
myDataSet.AcceptChanges()
myConnection.Close()
Catch ex As Exception
Throw
Finally
myCommand = Nothing
myDataAdapter = Nothing
myBuilder = Nothing
CType(myConnection, IDisposable).Dispose()
End Try
End If
End Function
我瞭解的情況是,我需要刷新數據源的網格,這樣,它反映所做的更改。爲了實現這一點,我希望通過將刷新過程掛接到datagridview中的事件來刷新網格。然而,我所嘗試的事件似乎都沒有奏效。對於到目前爲止嘗試過的每個事件,我都收到了錯誤,表示在事件中不允許刷新數據源。反思這似乎是合乎邏輯的。有沒有與datagridview關聯的事件,我可以使用它來強制刷新數據源?
DGV只是向用戶提供* data *的* view *的手段;數據庫相關事件的方式並不多。但是,DataAdapter和DataTable組合功能非常強大,但該代碼看起來並沒有充分利用這些功能。 DataTable可以在更新後刷新以獲取更改。來自DataAdapter的事件在某些情況下可能會有用 – Plutonix