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我有一个正在开发的 Web API Odata 服务。控制器支持异步，但我似乎找不到任何关于如何在从 OData 服务中提取数据时加载 DataGridView 异步的好示例。我确实找到了这个链接，其中有一些内容，但我不知道如何完成其​​余部分，因为我目前必须将 DataServiceQuery 转换为列表或 DataSource 失败。 http://msdn.microsoft.com/en-us/library/dd756367(v=vs.110).aspx
我的代码是这样的。

Private Sub getDataButton_Click(sender As Object, e As EventArgs) Handles getDataButton.Click
    ' Define the delegate to callback into the process 
    Dim callback As AsyncCallback = AddressOf OnLogsQueryComplete

    ' Define the query to execute asynchronously that returns  
    ' all customers with their respective orders. 
    Dim query As DataServiceQuery(Of LogServiceReference.Log) = (From log In context.Logs
                                                                   Select log)

    ' Begin query execution, supplying a method to handle the response 
    ' and the original query object to maintain state in the callback.
    DataGridView1.DataSource = query.BeginExecute(callback, query)
End Sub

Private Function OnLogsQueryComplete(ByVal result As IAsyncResult) As List(Of LogServiceReference.Log)
    ' Get the original query from the result. 
    Dim query As DataServiceQuery(Of LogServiceReference.Log) = _
        CType(result.AsyncState, DataServiceQuery(Of LogServiceReference.Log))

    Return query.EndExecute(result).ToList()
End Function

我可以阅读/编码 C# 或 VB，所以如果你有任何一个例子，我都会听……

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1 回答 1

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虽然这并不是真正逐行异步填充网格，但它正在填充整个数据源异步。这是我使用的代码。

Private gridRows As List(Of LogServiceReference.Log) = New List(Of LogServiceReference.Log)()
Private Delegate Sub UpdateUI()
Private oUpdateUI As UpdateUI

Private Sub getDataButton_Click(sender As Object, e As EventArgs) Handles getDataButton.Click
    Try
        gridRows.Clear()
        DataGridView1.DataSource = Nothing

        oUpdateUI = New UpdateUI(AddressOf DoUpdateUI)

        ' Define the delegate to callback into the process 
        Dim callback As AsyncCallback = AddressOf OnLogsQueryComplete

        ' Define the query to execute asynchronously that returns  
        ' all customers with their respective orders. 
        Dim query As DataServiceQuery(Of LogServiceReference.Log) = (From log In context.Logs
                                                                       Select log)

        ' Begin query execution, supplying a method to handle the response 
        ' and the original query object to maintain state in the callback.
        query.BeginExecute(callback, query)
    Catch ex As Exception

    End Try
End Sub

Private Sub DoUpdateUI()
    DataGridView1.DataSource = gridRows
End Sub

Private Sub OnLogsQueryComplete(ByVal result As IAsyncResult)
    ' Get the original query from the result. 
    Dim query As DataServiceQuery(Of LogServiceReference.Log) = _
        CType(result.AsyncState, DataServiceQuery(Of LogServiceReference.Log))

    ' Complete the query execution. 
    For Each log As LogServiceReference.Log In query.EndExecute(result)
        gridRows.Add(log)
    Next

    Invoke(oUpdateUI)
End Sub
于 2014-04-14T18:11:18.690 回答