INotifyPropertyChanged

INotifyPropertyChanged

现在我有一个只显示一个月的日历(我传入的每个月)。我试图让用户从组合框中选择月份和年份并更新日历。我正在使用我熟悉的 observablecollection 进行绑定(bind)。我不知道 INotifyPropertyChanged 是如何工作的。我以前从未使用过它。非常感谢任何帮助或建议。这是我到目前为止:

public class Schedule : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void Update(int propertyName)
    {
        if (propertyName != null)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
                 handler.Invoke(this, new PropertyChangedEventArgs(propertyName.ToString()));
        }
    }


   // public void UpdateCal(PropertyChangedEventArgs e)
   // {
    //    if (PropertyChanged != null)
    //        PropertyChanged(this, e);
  //  }
    public string MonthWeek { get; set; }
    public string Year { get; set; }
    public string Month { get; set; }
    public string day { get; set; }
    public string WeekOfYear { get; set; }
    public string dayofweek { get; set; }

   // public string month {
    //    get {return Month; }
    //    set
    //    {
     //       UpdateCal(new PropertyChangedEventArgs("month"));
      //  }
   // }
    public int WeekNo { get; set; }
    public int WeekDay { get; set; }
    public DateTime Date { get; set; }
 }

---这是另一个计算每个日期在网格上的位置的类----
           public SchedulePage(MainWindow parentForm)
    {
        InitializeComponent();

        pick = Convert.ToInt32(comboMonth.SelectedItem) + 1;
        _parentForm = parentForm;
        // DateTime date = new DateTime(year, month, day);
        var t = new List<Schedule>();
        DateTime curr = DateTime.Now;
      //  comboMonth.Items.Add(curr.Month);
        DateTime newcurr = new DateTime(2011, pick, 1);
     //   pickdate = datePickercal.SelectedDate;
      //  DateTime newcurr = new DateTime(curr.Year, curr.Month, 1);
        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 == pick; newcurr = newcurr.AddDays(1))
        {
            var sched = new Schedule();
            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();
            t.Add(sched);

                _parentForm.bindings.schedule.Add(new Schedule { WeekNo = newcurr.GetWeekOfMonth()-1, WeekDay = (int)newcurr.DayOfWeek, day = newcurr.Day.ToString() });

        }
        lblDate.Content = (newcurr.Month -1) + "/" + newcurr.Year;

         DataContext = _parentForm.Bindings;

---而这个类使 observablecollections-----
           public partial class BindingCamper
{  // This class assist in binding campers from listview to the textboxes on the camperspage
    public ObservableCollection<Camper> Campers { get; set; }
    public ObservableCollection<Staff> StaffMembers { get; set; }
    public ObservableCollection<Schedule> schedule { get; set; }
    public BindingCamper()
    {
        Campers = new ObservableCollection<Camper>();
      StaffMembers = new ObservableCollection<Staff>();
      schedule = new ObservableCollection<Schedule>();
    }

最佳答案

这是您通常如何实现 INotifyPropertyChanged :

public class Schedule : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }

    private string _monthWeek;
    public string MonthWeek
    {
        get { return _monthWeek; }
        set
        {
            if (value != _monthWeek)
            {
                _monthWeek = value;
                OnPropertyChanged("MonthWeek");
            }
        }
    }

    // And so on for other properties...

}

基本上,您只需要在每次更新属性时触发 PropertyChanged 事件,因此每个 setter 都必须调用 OnPropertyChanged 。请注意,您不能使用自动实现的属性来执行此操作,因为您需要在 setter 中添加自定义逻辑。

关于c# - INotifyPropertyChanged 和 ObservableCollection WPF,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/7934236/

10-11 11:58