使用asynch頁面的asp.net長期運行過程

Question

我有一個報告需要大約2到3分鍾才能提取所有數據

所以我試圖使用ASP.net Asynch頁面來防止超時。 但無法正常工作

這是我在做什么：

private delegate List<PublishedPagesDataItem> AsyncReportDataDelegate();

private AsyncReportDataDelegate longRunningMethod;

private List<PublishedPagesDataItem> reportData;

public PublishedPagesReport() // this is the constructor
{
    reportData = new List<PublishedPagesDataItem>();
    longRunningMethod = GetReportData;
}


protected void Page_Load(object sender, EventArgs e)
{
    this.PreRenderComplete +=
        new EventHandler(Page_PreRenderComplete);

    AddOnPreRenderCompleteAsync(
        new BeginEventHandler(BeginAsynchOperation),
        new EndEventHandler(EndAsynchOperation)
    );
}

private List<PublishedPagesDataItem> GetReportData()
{
    // this is a long running method
}

private IAsyncResult BeginAsynchOperation(object sender, EventArgs e, AsyncCallback cb, object extradata)
{
    return longRunningMethod.BeginInvoke(cb, extradata);
}

private void EndAsynchOperation(IAsyncResult ar)
{
    reportData = longRunningMethod.EndInvoke(ar);
}

private void Page_PreRenderComplete(object sender, EventArgs e)
{
    reportGridView.DataSource = reportData;
    reportGridView.DataBind();
}

所以我有一個代表長期運行方法（GetReportData）的委托。

我試圖按照這篇文章來稱呼它：

http://msdn.microsoft.com/zh-CN/magazine/cc163725.aspx

長時間運行的方法確實在調試器中完成，但是EndAsynchOperation和Page_PreRenderComplete方法上的斷點永遠不會被擊中

知道我在做什么錯嗎？

Answer 1

下面的代碼有效。 不知道有什么區別，除了有一個if (!IsPostBack)

無論如何，現在解決了

private delegate List<PublishedPagesDataItem> AsyncReportDataDelegate();

private AsyncReportDataDelegate longRunningMethod;

private List<PublishedPagesDataItem> reportData;

public asynchtest()
{
    reportData = new List<PublishedPagesDataItem>();
    longRunningMethod = GetReportData;
}

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        // Hook PreRenderComplete event for data binding
        this.PreRenderComplete +=
            new EventHandler(Page_PreRenderComplete);

        // Register async methods
        AddOnPreRenderCompleteAsync(
            new BeginEventHandler(BeginAsyncOperation),
            new EndEventHandler(EndAsyncOperation)
        );
    }
}
IAsyncResult BeginAsyncOperation(object sender, EventArgs e,
    AsyncCallback cb, object state)
{
    return longRunningMethod.BeginInvoke(cb, state);
}

void EndAsyncOperation(IAsyncResult ar)
{
    reportData = longRunningMethod.EndInvoke(ar);
}

protected void Page_PreRenderComplete(object sender, EventArgs e)
{
    Output.DataSource = reportData;
    Output.DataBind();
}