Benachrichtigen Sie Ein Objekt als eine Eigenschaft eines anderen Objekts ändert

Ich habe ein parent-Objekt namens Seite, die eine Liste von Objekten, die auch als Kontrolle:

public class Page
{
   List<CustomControl> controls {get;set;}
}

Des CustomControl-Klasse hat die folgende Definition:

public class CustomControl
{
 string Name {get;set;}
 string Value {get;set;}
}

Sagen für die Instanz der Page-Klasse hat zwei CustomControls A und B. Ist es möglich zu Benachrichtigen Custom Control B, wenn der Wert der Eigenschaft des Benutzerdefinierten Steuerelements verändert, so dass es einige seiner Eigenschaften ändern.

Ich dachte der Implementierung des INotifyPropertyChanged event auf dem CustomControl-Klasse jetzt, wie ich informieren eine Instanz des CustomControl, wenn eine andere Instanz der gleichen Klasse hat einige Eigenschaft der Modifizierten.

InformationsquelleAutor Manthan | 2010-08-25
  1. 5
    public class CustomControl : INotifyPropertyChanged
{
    private string _name;
    public string Name
    {
        get { return _name; }
        set
        {
            if (_name == value) return;
            _name = value;
            PropertyChanged(this, new PropertyChangedEventArgs("Name"));
        }
    }

    private string _value;
    public string Value
    {
        get { return _value; }
        set
        {
            if (_value == value) return;

            _value = value;
            PropertyChanged(this, new PropertyChangedEventArgs("Value"));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged = delegate { };

    internal virtual void OnSiblingInPagePropertyChanged(object sender, PropertyChangedEventArgs args)
    {

    }
}

public class CustomControlObservableColletion : ObservableCollection<CustomControl>
{
    //Required because, by default, it is not possible to find out which items
    //have been cleared when the CollectionChanged event is fired after a .Clear() call.
    protected override void ClearItems()
    {
        foreach (var item in Items.ToList())
            Remove(item);
    }

}

public class Page
{
    public IList<CustomControl> Controls { get; private set; }

    public Page()
    {
        var controls = new CustomControlObservableColletion();
        controls.CollectionChanged += OnCollectionChanged;
        Controls = controls;
    }

    private void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        switch (e.Action)
        {
            case NotifyCollectionChangedAction.Add:
                RegisterControls(e.NewItems);
                break;

            case NotifyCollectionChangedAction.Replace:
                RegisterControls(e.NewItems);
                DeRegisterControls(e.OldItems);
                break;

            case NotifyCollectionChangedAction.Remove:
                DeRegisterControls(e.OldItems);
                break;
        }
    }

    private void RegisterControls(IList controls)
    {
        foreach (CustomControl control in controls)
            control.PropertyChanged += OnControlPropertyChanged;
    }

    private void DeRegisterControls(IList controls)
    {
        foreach (CustomControl control in controls)
            control.PropertyChanged -= OnControlPropertyChanged;
    }

    private void OnControlPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        foreach (var control in Controls.Where(c => c != sender))
            control.OnSiblingInPagePropertyChanged(sender, e);
    }
}
    • Vielen Dank für die Lösung, werde es probieren und Euch wissen lassen, wie es ging
    • Sorry für die Verspätung. Es funktioniert für mich. Dank
    InformationsquelleAutor Ani
  2. 0
    using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PropertyNotificatioDemo

{

    class Program

    {

        static void Main(string[] args)

        {

            PropertyNotification notification = new PropertyNotification();   //Create an object of PropertyNotification class.

            //Create EmployeeValueChange handler.

            PropertyNotification.EmployeeValueChange += new PropertyNotification.EmployeeNameHandler(PropertyNotification_EmployeeValueChange);



            //Display a message.

            Console.Write("Enter Value  :  ");

            //Read a value and initilize it in property.

            notification.EmployeeName = Console.ReadLine();

        }



        //Handler for property notification is created.

        static void PropertyNotification_EmployeeValueChange(object sender, EventArgs e)

        {

            Console.WriteLine("Employee name is changed."+sender);

        }

    }



    public class PropertyNotification

    {

        //Create a private variable which store value.

        private static string _employeeName;

        //Create a delegate of named EmployeeNamed=Handler

        public delegate void EmployeeNameHandler(object sender, EventArgs e);



        //Create a event variable of EmployeeNameHandler

        public static event EmployeeNameHandler EmployeeValueChange;



        //Create a static method named OnEmployeeNameChanged

        public static void OnEmployeeNameChanged(EventArgs e)

        {

            if (EmployeeValueChange != null)

                EmployeeValueChange(_employeeName, e);

        }



        //Create a property EmployeeName

        public string EmployeeName

        {

            get

            {

                return _employeeName;

            }

            set

            {

                //Check if value of property is not same.

                if (_employeeName != value)

                {

                    OnEmployeeNameChanged(new EventArgs());

                    _employeeName = value;

                }

            }

        }

    }

}
    InformationsquelleAutor Kamal Sukla
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