在 Silverlight 中刷新 DataGrid

Question

我有 DataGrid 里面有列。

我希望DataGrid每 3 秒刷新一次，其中包含来自服务的数据。

我需要Scroll 每次刷新都不会跳到DataGrid 的顶部，并保持在Scroll 的同一位置。有可能吗？

这是我的代码：

<sdk:DataGrid  Grid.Row="1" FlowDirection="RightToLeft" ColumnHeaderHeight="32"
      AutoGenerateColumns="False" Name="RealTimeReportDataGrid" 
      RowEditEnded="LinesDataGrid_RowEditEnded" RowHeight="40">
      <sdk:DataGrid.Columns>...</sdk:DataGrid.Columns>
</sdk:DataGrid>

这是后面的代码：

        public RealTimeReport()
    {
        InitializeComponent();
        Loaded += OnViewLoaded;
        RealTimeReportService.RealTimeReportServiceClient RTws = new RealTimeReportService.RealTimeReportServiceClient();
        RTws.GetRealTimeReportAsync();
        RTws.GetRealTimeReportCompleted += new EventHandler<RealTimeReportService.GetRealTimeReportCompletedEventArgs>(RTws_GetRealTimeReportCompleted);

    }

    void RTws_GetRealTimeReportCompleted(object sender, RealTimeReportService.GetRealTimeReportCompletedEventArgs e)
    {
        var t = e.Result.ToList();
        RealTimeReportDataGrid.ItemsSource = new System.Collections.ObjectModel.ObservableCollection<ShahalDialerRT.RealTimeReportService.RealTimeReport>(e.Result.ToList());
    }


    private void OnViewLoaded(object sender, RoutedEventArgs e)
    {
        Start();
    }

    private void OnUpdaterTimerTick(object sender, EventArgs e)
    {
        RealTimeReportService.RealTimeReportServiceClient RTws = new RealTimeReportService.RealTimeReportServiceClient();
        RTws.GetRealTimeReportAsync();
        RTws.GetRealTimeReportCompleted += new EventHandler<RealTimeReportService.GetRealTimeReportCompletedEventArgs>(RTws_GetRealTimeReportCompleted);
    }


    public void Start()
    {
        InitializeRefreshDataTimer();
    }


    public void InitializeRefreshDataTimer()
    {
        _updaterTimer.Interval = new TimeSpan(0, 0, 0, 0, 3000);
        _updaterTimer.Tick += OnUpdaterTimerTick;
        _updaterTimer.Start();
    }

先谢谢了。

更新： @StepUp，这是我做的唯一改变，根据你说的，但仍然没有改变:(

void RTws_GetRealTimeReportCompleted(object sender, RealTimeReportService.GetRealTimeReportCompletedEventArgs e)
{
    var t = e.Result.ToList();

    RealTimeReportDataGrid.ItemsSource = new System.Collections.ObjectModel.ObservableCollection<ShahalDialerRT.RealTimeReportService.RealTimeReport>(e.Result.ToList());

    this.RealTimeReportDataGrid.Dispatcher.BeginInvoke(() =>
    {
        RealTimeReportDataGrid.ScrollIntoView(
        RealTimeReportDataGrid.SelectedItem,
        RealTimeReportDataGrid.CurrentColumn);
    });
    //RealTimeReportDataGrid.ItemsSource = new System.Collections.ObjectModel.ObservableCollection<ShahalDialerRT.RealTimeReportService.RealTimeReport>(e.Result.ToList());
    //RealTimeReportDataGrid.UpdateLayout();
    //RealTimeReportDataGrid.ScrollIntoView(RealTimeReportDataGrid.SelectedItem, RealTimeReportDataGrid.Columns[0]);
}

Answer 1

每 3 秒刷新一次，只需 use Timer class：

System.Timers.Timer aTimer = new System.Timers.Timer();
aTimer.Elapsed+=new ElapsedEventHandler(OnTimedEvent);
aTimer.Interval=3000;
aTimer.Enabled=true;


// Specify what you want to happen when the Elapsed event is raised.
private static void OnTimedEvent(object source, ElapsedEventArgs e)
{
     //add new data
}

Elapsed 事件将每 X 秒引发一次，以毫秒为单位由 Timer 对象的 Interval 属性指定。它将调用您指定的Event Handler 方法，在上面的示例中为OnTimedEvent。

在DataGrid 中保持Scroll 的相同位置：

yourDataGrid.ItemsSource = data; 
yourDataGrid.UpdateLayout(); 
yourDataGrid.ScrollIntoView(theDataGrid.SelectedItem, theDataGrid.Columns[0]);

更新：

yourDataGrid.Dispatcher.BeginInvoke(() =>
{
    yourDataGrid.Focus();      
    yourDataGrid.SelectedItem=whateverYouWant;
    yourDataGrid.CurrentColumn=yourDataGrid.Columns[0];
    yourDataGrid.ScrollIntoView(yourDataGrid.SelectedItem, yourDataGrid.CurrentColumn);
});

或者：

yourDataGrid.SelectedIndex = 5; // the index you want to select
yourDataGrid.UpdateLayout();
yourDataGrid.ScrollIntoView(Grid.SelectedItem, 0);