如何使用INotifyPropertyChanged更新ListBox

Question

我有一个日历，我在日历itemscontrol中嵌套了一个itemscontrol，以便我可以在gridcell（日期）中显示要为其生成事件的事件。压光机是7列6行。现在我只是使用列表框来实际显示事件（标题）。我可以在启动时添加项目，但我希望能够在程序已经运行时添加/删除/更改。我曾尝试过一次INotifyPropertyChanged，但我无法弄清楚它是否适合我的生活。如果某人可以拿走我拥有的东西并给我看，或者给我提示我如何做到这一点，我会非常感激。

类，我可以启动前添加（项）：

public class eventProperties : ObservableCollection<eventsTitles> 
{ 
    //public string Eventer { get; set; } 

    public eventProperties() : base() 
    { 
     Add(new eventsTitles("First Test")); 
     Add(new eventsTitles("First Test#2")); 

    } 

这是窗口（类）时，我想一旦程序启动和运行已添加事件弹出。我需要弄清楚如何使用这个窗口，以及如何将它添加到某一特定日期（栅格单元）添加项目

public Event(MainWindow parentform) 
    { 

     InitializeComponent(); 
     _parentForm = parentform; 
     //this.month = month; 
     //this.day = day; 
     //this.year = year; 
     lblCreateEvent.Content = "Create Event For " + month + "/" + day + "/" + year; 

    } 

    private void btnSubmit_Click(object sender, RoutedEventArgs e) 
    { 
     month = Convert.ToInt32(txtMonth.Text); 
     day = Convert.ToInt32(txtDay.Text); 
     year = Convert.ToInt32(txtYear.Text); 



     Schedule sched = new Schedule(); 
     DateTime curr = DateTime.Now; 
     int[] m = new int[7]; 
     DateTime newcurr = new DateTime(year, month, day); 

     var cal = System.Globalization.DateTimeFormatInfo.CurrentInfo.Calendar; 
     var ms = cal.GetWeekOfYear(new DateTime(newcurr.Year, newcurr.Month, 1), System.Globalization.CalendarWeekRule.FirstDay, System.DayOfWeek.Sunday); 

      // for (var i = 1; newcurr.Month == 11; newcurr = newcurr.AddDays(1)) 
      // { 

       var month_week = (newcurr.Day/7); 
       sched.MonthWeek = newcurr.GetWeekOfMonth().ToString(); 
       sched.Month = newcurr.Month.ToString(); 
       sched.Year = newcurr.Year.ToString(); 
       sched.day = newcurr.Day.ToString(); 
       sched.WeekOfYear = cal.GetWeekOfYear(newcurr, System.Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Sunday).ToString(); 
       sched.dayofweek = newcurr.DayOfWeek.ToString(); 


       //Here is where the calender is created. By looping through all the days in the selected month it will find the weeknumber and day of the week --> 
       // that that particular date belongs to and place in the correct gridcell. 
       _parentForm.bindings.schedule.Add(new Schedule { WeekNo = newcurr.GetWeekOfMonth() - 1, WeekDay = (int)newcurr.DayOfWeek, day = newcurr.Day.ToString(), eventTitle = "Camper Calender" }); 

这是实际的压延XAML，我需要绑定的一切。

 </customgridcontrol:GridControl> 


    </ItemsPanelTemplate> 
     </ItemsControl.ItemsPanel> 
      <ItemsControl.ItemTemplate> 
       <DataTemplate> 
        <StackPanel> 
         <Button Content="{Binding day}" Width="175" HorizontalAlignment="Stretch" VerticalAlignment="Top" VerticalContentAlignment="Top" HorizontalContentAlignment="Left" Name="btnCalenderDate" Click="btnCalenderDate_Click" Loaded="btnCalenderDate_Loaded" Height="18" FontSize="10" FontWeight="Bold"> 
         </Button> 

         <ItemsControl Height="60" VerticalAlignment="Stretch"> 
          <ItemsControl.Resources> 
           <src:eventProperties x:Key="dataList"/> 
          </ItemsControl.Resources> 
          <ItemsControl.Items> 
           <ListBox ItemsSource="{Binding Source= {StaticResource dataList} }" DisplayMemberPath="EventTitle" VerticalAlignment="Top" IsSynchronizedWithCurrentItem="True">    
           </ListBox> 
          </ItemsControl.Items> 
         </ItemsControl> 
        </StackPanel> 
       </DataTemplate> 
      </ItemsControl.ItemTemplate> 
    <!-- ItemContainerStyle --> 
     <ItemsControl.ItemContainerStyle> 

      <Style >   
        <Setter Property="Grid.Column" Value="{Binding WeekDay}" /> 
       <Setter Property="Grid.Row" Value="{Binding WeekNo}" /> 
      </Style> 
      </ItemsControl.ItemContainerStyle> 
    </ItemsControl> 

eventTitles类

namespace Camp_ 
    { 
     public class eventsTitles 
     { 
      public string eventTitle {get; set;} 

      public eventsTitles()//String ev) 
      { 
       // this.eventTitle = ev; 
      } 

      public string EventTitle 
      { 
       get { return eventTitle; } 
       set { eventTitle = value; } 
      } 
     }   
    } 

Answer 1

Harsh's answer对于您如何实现INotifyPropertyChanged是正确的，但是您只需要为单个属性实现该功能。如果你正在寻找以通知集合改变了UI，使用ObservableCollection类

所以，如果你有包含Event.EventTitle一个标签，你想改变EventTitle在后台代码，你将实施INotifyPropertyChanged上EventClass，以便当您更新myEvent.EventTitle时，UI中的标签将自动更新为新值。

如果你有一个列表框（或ItemsControl的），你要自动当您添加或删除项目向/从集合，只需将ListBox绑定到ObservableCollection属性，它会自动更新UI时，会添加项目更新或从中删除。

例如，

<ItemsControl.ItemTemplate> 
    <DataTemplate> 
     <StackPanel> 
     <Button Content="{Binding day}" Click="AddEvent" /> 

     <ItemsControl Height="60" ItemsSource="{Binding Events}"> 
      <ItemsControl.ItemTemplate> 
       <DataTemplate> 
        <TextBlock Text="{Binding EventTitle}" /> 
       <DataTemplate> 
      </ItemsControl.ItemTemplate> 
     </ItemsControl> 
     </StackPanel> 
    </DataTemplate> 
</ItemsControl.ItemTemplate> 

在这个例子中，你Schedule类将有一个名为Events属性，它是一个ObservableCollection<Event>。要添加新的事件，你可以使用这样的事情：

void AddEvent(object sender, EventArgs e) 
{ 
    // Get the DataContext for the Button, which should be of type Schedule 
    Schedule day = (sender as Button).DataContext as Schedule; 

    // Add New Event. Since this is an ObservableCollection, UI will automatically update 
    day.Events.Add(new Event { EventTitle = "Test Event" }); 
} 

作为一个侧面说明，你应该检查出一些.Net naming conventions

Answer 2

我想到eventTitles必须有所以这里不执行INotifyPropertyChanged界面的一些问题是实施细节。

假设eventTitles类

public class eventTitles : INotifyPropertyChanged 
{ 
    private string _eventtitle = string.Empty; 

    public string EventTitle 
    { 
     get {return _eventtitle;} 

     set 
     { 
      if (value != _eventtitle) 
      { 
       _eventtitle = value; 
       NotifyPropertyChanged("EventTitle"); 
      } 
     } 
    } 

    public event PropertyChangedEventHandler PropertyChanged; 

    private void NotifyPropertyChanged(String info) 
    { 
     if (PropertyChanged != null) 
     { 
      PropertyChanged(this, new PropertyChangedEventArgs(info)); 
     } 
    } 
} 

有关进一步的参考，你可以检查这个MSDN Post。