如何在启动

Question

我尝试使用DataAdapter.Update在数据库中进行批量更新，用户可以选择取消操作。

问题：当用户点击取消按钮时，如何停止更新操作？

我的代码::

 Log("@@@@@ Saving BMPImages paths to the database @@@@@")
 objCommandBuilder = New SqlCommandBuilder(daImages)
 SavingImageObj.MyProgressBar.Maximum = tblImages.GetChanges.Rows.Count
 AddHandler tblImages.RowChanged, New DataRowChangeEventHandler(AddressOf tblImages_changed)
 daImages.Update(dsMAP, "BMPImages")

这是RowChanged Handler ::

Private Sub tblImages_changed(ByVal sender As Object, ByVal e As System.Data.DataRowChangeEventArgs)
    'Increment progress bar
    SavingImageObj.ThreadTask()

    If SkipFraming = True Then
        ' Here I should do something to stop the daImages.Update
        ' from continuing to execute
    End If
End Sub

我设置了一个标志[ SkipFraming ]，表示我应该在点击取消按钮时停止操作。

Answer 1

好的，我找到了解决问题的方法： 我应该为dataAdapter.RowUdpated而不是dataTable.RowChanged创建一个事件处理程序，以便能够停止更新[这只是一个状态更新= D（ args.Status = UpdateStatus.SkipAllRemainingRows ）]

以下是代码示例：

    ' Reset Updating progress counter
    UpdatingProgressCounter = 0

    'Open connection to update database
    objConn.Open()

    'Update database
    Log("@@@@@ Saving BMPImages paths to the database @@@@@")
    objCommandBuilder = New SqlCommandBuilder(daImages)
    SavingImageObj.MyProgressBar.Maximum = tblImages.GetChanges.Rows.Count
    AddHandler daImages.RowUpdated, New SqlRowUpdatedEventHandler(AddressOf daImages_updated)
    Log("========== Total Rows to be updated = [" & tblImages.GetChanges.Rows.Count & "] ==========")
    daImages.Update(dsMAP, "BMPImages")

    'Close database connection
    objConn.Close()


 Private Sub daImages_updated(ByVal sender As Object, ByVal args As System.Data.SqlClient.SqlRowUpdatedEventArgs)
    'Increment progress bar
    SavingImageObj.ThreadTask()

    ' Increment progress counter
    UpdatingProgressCounter += 1

    'Give control on UI
    If UpdatingProgressCounter Mod 10 = 0 Then
        Application.DoEvents()
        SkipFraming = True      'For Testing
    End If

    ' Skip updating remaining rows in case of cancelling the framing
    If SkipFraming = True Then
        Log("@@@@@@@@@@@@@@@@@ Skipping remaining rows @@@@@@@@@@@@@@@@@")
        args.Status = UpdateStatus.SkipAllRemainingRows
    End If
End Sub

我希望能帮助有类似情况的人。