mysql - DataGridView中的List(Of T)重载问题

我正在使用List(Of T)来包含我的数据库字段（invoice\u id和item\u id），并希望在DataGridView中显示它。首先，我将它们声明为一个类，然后将它们添加到我的列表中，然后在DataGridView中显示它，但是当我编译它时，程序没有响应。
我的猜测是，我的数据库源太大，因为当我更改源（数据库字段）时，它工作得很好。那么，我该如何解决这个List(Of T)容量问题呢？
这是我的代码：

Sub view()

    Dim msql2 As String
    msql2 = "select invoice_id, item_id from detail"
    Dim arayD As New List(Of INVOICE)

    CMD2 = New MySqlCommand(msql2, conn.konek)

    Try

        Dim res = CMD2.ExecuteReader()
        Dim INVO As INVOICE = Nothing
        While res.Read()
            INVO = New INVOICE
            With INVO
                .invoice_id = hasil2.GetString("invoice_id")
                .item_id = hasil2.GetString("item_id")
            End With
            arayD.Add(INVO)

        End While
        dgv.DataSource = arayD
    Catch ex As Exception
        MessageBox.Show("ERROR")

    End Try
End Sub

Public Class INVOICE
    Private _kodeF As Integer
    Public Property invoice_id() As Integer
        Get
            Return _kodeF
        End Get
        Set(ByVal value As Integer)
            _kodeF = value
        End Set
    End Property

    Private _kodeBrg As String
    Public Property item_id() As String
        Get
            Return _kodeBrg
        End Get
        Set(ByVal value As String)
            _kodeBrg = value
        End Set
    End Property
End Class

最佳答案

如果需要快速解决方案，请在While Loop中添加以下行：

While res.Read()
    Application.DoEvents()
    ...
End While

或者使用BackgroundWorker，如下所示：

Private WithEvents bgWorker As New System.ComponentModel.BackgroundWorker
Private arayD As New List(Of INVOICE)

Sub view()
    bgWorker.RunWorkerAsync()
End Sub

Private Sub bgWorker_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles bgWorker.DoWork
    Dim dReader As DataReader

    Using YourConnection
        Using YourCommand
            YourConnection.Open()
            dReader = YourCommand.ExecuteReader()
            If dReader.HasRows Then
                While dReader.Read
                    arayD.Add(New INVOICE With {
                                                .invoice_id = hasil2.GetString("invoice_id"),
                                                .item_id = hasil2.GetString("item_id")
                                               }
                             )
                End While
            End If
        End Using
    End Using
End Sub

Private Sub bgWorker_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles bgWorker.RunWorkerCompleted
    MsgBox("Ready to go")
    dgv.DataSource = arayD
End Sub

此外，您还可以获得结果的计数，并将其与progressbar一起使用。

关于mysql - DataGridView中的List(Of T)重载问题，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/20602950/