C＃WPF listView添加时无法实时更新

Question

I have a listView binded to a class:

 <ListView x:Name="lvInfo" HorizontalAlignment="Left" Height="277" Margin="23,63,0,0" VerticalAlignment="Top" Width="750">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="#" Width="20" DisplayMemberBinding="{Binding execNumber}"/>
                <GridViewColumn Header="Function" Width="120" DisplayMemberBinding="{Binding currentFunction}"/>
                <GridViewColumn Header="Message" Width="300"  DisplayMemberBinding="{Binding pcdMessage}"/>
                <GridViewColumn Header="Event Type" Width="75" DisplayMemberBinding="{Binding pcdEventType}"/>
                <GridViewColumn Header="Event" Width="150" DisplayMemberBinding="{Binding pcdEvent}"/>
                <GridViewColumn Header="Timing" Width="50" DisplayMemberBinding="{Binding strTime}"/>
            </GridView>
        </ListView.View>
    </ListView>

while in Codebehind the class is

private class PcdStatus
    {
        public PcdStatus(int _execNumber, String _currentFunction, String _pcdMessage, Helper.ePcdEventType _pcdEventType, Helper.ePcdEvent _pcdEvent,String _strTime )
        {
            execNumber = _execNumber;
            currentFunction = _currentFunction;
            pcdMessage = _pcdMessage;
            pcdEventType = _pcdEventType;
            pcdEvent = _pcdEvent;
            strTime = _strTime;
        }
        public int execNumber { get; set; }
        public String currentFunction { get; set; }
        public String pcdMessage { get; set; }
        public Helper.ePcdEventType pcdEventType { get; set; }
        public Helper.ePcdEvent pcdEvent { get; set; }
        public String strTime { get; set; }
    }

the class is updated via event:

private void MyPcd_OnStatusChange(string _currentFunction, string _PCDMessage, Helper.ePcdEventType _pcdEventType, Helper.ePcdEvent _pcdEvent)
    {
        String strTime;
        if (lastTime == default(DateTime))       
            strTime = "---";
        else
        {
            TimeSpan ts = DateTime.Now - lastTime;
            strTime = ts.TotalSeconds.ToString("0.000")+ "\"";
        }
        lastTime = DateTime.Now;

        PcdStatus newStatus = new PcdStatus(execNumber, _currentFunction, _PCDMessage, _pcdEventType, _pcdEvent, strTime);
        Application.Current.Dispatcher.BeginInvoke(new Action(() => this.ocList.Add(newStatus)));
        //ocList.Add(newStatus);           
    }

the class update is done properly but not in real time. I have added a console.Beep() that warns me when the an event is fired from a library. So Event from Library ---> My_PcdOnStatusChange ---> ocList.Add ---> listView updated. I expected an update per each beep but the listView is updated only at the end of all the s/r.

EDIT Sorry forgot to mention that the ocList below stands for:

 ObservableCollection<PcdStatus> ocList = new ObservableCollection<PcdStatus>();

EDIT2 I am pretty sure that the problem doesn't rely on the ListView or the binding itself. I have added a property which changes a picture. Red when program started and green when idle.

  private bool _isBusy;
    public bool IsBusy
    {
        get { return _isBusy; }
        set
        {
            _isBusy = value;               
            if (value)
                imgBusy.Dispatcher.Invoke(new Action(() => imgBusy.Source = new BitmapImage(new Uri(@"../../Resources/redBall.png", UriKind.Relative))));
            else
                imgBusy.Dispatcher.Invoke(new Action(() => imgBusy.Source = new BitmapImage(new Uri(@"../../Resources/greenBall.png", UriKind.Relative))));
        }
    }

The expected behaviour is:

idle --> green
started ---> red
terminated ---> green

while its behaviour is:

idle ---> green
started --->green
midway ---> red
terminated --->green.

I am new with WPF in winforms there was a Mainform.Update. Is there something similar here?

Thanx for any help Patrick

Answer 1

you need to bind the ItemSource property to a collection that implements INotifyCollectionChanged

the simplest of these is ObservableCollection

PcdStatus should also implement INotifyPropertyChanged if you want property changes to update