Question

我已经查看了几个与动态用户界面相关的问题，但我仍然不了解我所缺少的内容。另外，我已经关注了如何使用任务的教程，但我的理解仍然有限。以下是我想要实现的目标：

我的应用程序正在幕后做一些工作，但我希望我的UI能够响应。我尝试过以下操作（请参阅代码），但在调用调度程序之前，UI不会开始更新。我希望UI状态为：

创建... - 单击CreatePivotTableButton后立即
建立连接... - 在调用provider.GetReportData方法之前
连接成功或连接失败，具体取决于结果

完成。

 <!-- language: lang-cs -->
 private void CreatePivotTableButton(object sender, RoutedEventArgs e)
{

    this.StatusToBeDisplayed.Content = "Creating...";
    this.DescriptionLabel.IsEnabled = false;
    this.TextBlockBorder.IsEnabled = true; 

    List<CombinedData> items = (List<CombinedData>)CustomerComboBox.ItemsSource;
    List<int> selectedItems = new List<int>();
    foreach (CombinedData item in items)
    {
        if (item.IsSelected)
        {
            selectedItems.Add(item.ReferenceId);
        }
    }

    PCTProvider provider = new PCTProvider();
    ExportToExcel export = new ExportToExcel();

    ExcelAutomation excelAutomation = new ExcelAutomation();

    this.ResultTextBlock.Text = "Establishing Connection";
    DataTable generateReportDataTable = provider.GetReportData(selectedItems);
    Excel.Workbook workbook = export.ExportDataTableToExcel(generateReportDataTable);
    Task updateTask = Task.Factory.StartNew(() =>
    {
        Dispatcher.Invoke(new Action(() => excelAutomation.CreatePivotTable(workbook)));
    }).ContinueWith(result =>
    {
        Dispatcher.Invoke(new Action(() => this.StatusToBeDisplayed.Content = "Done!"));
        Dispatcher.Invoke(new Action(() => OriginalStatus()));
    }, TaskScheduler.FromCurrentSynchronizationContext());

}

我非常感谢您的时间和帮助。

Answer 1

我认为您不需要ContinueWith和/或TaskScheduler 通过在Task中完成工作，您可以让UI线程响应消息泵。您可能希望将CreatePivotTableButton的更多工作转移到任务中。

请改为尝试：

private void CreatePivotTableButton(object sender, RoutedEventArgs e)
{

    this.StatusToBeDisplayed.Content = "Creating...";
    this.DescriptionLabel.IsEnabled = false;
    this.TextBlockBorder.IsEnabled = true; 
    // move the rest of the code into your Task to perform the work off the UI thread
    Task updateTask = Task.Factory.StartNew(() =>
    {
        List<CombinedData> items = (List<CombinedData>)CustomerComboBox.ItemsSource;
        List<int> selectedItems = new List<int>();
        foreach (CombinedData item in items)
        {
            if (item.IsSelected)
            {
                selectedItems.Add(item.ReferenceId);
            }
        }

        PCTProvider provider = new PCTProvider();
        ExportToExcel export = new ExportToExcel();

        ExcelAutomation excelAutomation = new ExcelAutomation();

        Dispatcher.Invoke(new Action(() => this.ResultTextBlock.Text = "Establishing Connection"));
        DataTable generateReportDataTable = provider.GetReportData(selectedItems);
        Excel.Workbook workbook = export.ExportDataTableToExcel(generateReportDataTable);

        excelAutomation.CreatePivotTable(workbook);
        Dispatcher.Invoke(new Action(() => this.StatusToBeDisplayed.Content = "Done!"));
        Dispatcher.Invoke(new Action(() => OriginalStatus()));
    });
}

如何动态更新我的UI

1 个答案: