c# - 如何动态更新我的 UI

Question

我已经查看了几个与动态 UI 相关的问题，但我仍然不明白我缺少什么。此外，我已经关注了有关如何使用任务的教程，但我的理解仍然有限。这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。我尝试了以下方法（参见代码），但 UI 在调用调度程序之前不会开始更新。我希望 UI 状态为：

1. 创建... - 单击 CreatePivotTableButton
2. 建立连接... -- 在调用 provider.GetReportData 方法之前
3. 连接成功或连接失败取决于结果

4. 完毕。

    <!-- 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/或可能不需要TaskScheduler 通过在任务中完成工作，您允许 UI 线程响应消息泵。您可能希望将更多的工作CreatePivotTableButton转移到任务中。

试试这个：

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()));
    });
}