C#利用委托实现属性改变时触发事件的范例

C#利用委托实现属性改变时触发事件的范例

public class MyClass
    {
        public event EventHandler<PropertyChagedEventArgs> MyPropertyChanging;
        public event EventHandler<PropertyChagedEventArgs> MyPropertyChanged;
        private int _myProperty;
        public int MyProperty
        {
            get { return _myProperty; }
            set
            {
                if (value != _myProperty)
                {
                    PropertyChagedEventArgs e = new PropertyChagedEventArgs("MyProperty", _myProperty, value);//初始化
                    if (this.MyPropertyChanging != null)
                    {
                        this.MyPropertyChanging(this, e);
                        if (e.Cancel) return;
                    }
                    _myProperty = (int)e.NewValue;
                    if (this.MyPropertyChanged != null)
                    {
                        this.MyPropertyChanged(this, e);
                    }
                }
            }
        }
    }
    /// <summary>
    /// 通用的类
    /// </summary>
    public class PropertyChagedEventArgs : EventArgs
    {
        public PropertyChagedEventArgs(string propertyName,object oldValue,object newValue)
        {
            PropertyName = propertyName;
            OldValue = oldValue;
            NewValue = newValue;
        }
        public bool Cancel { get; set; }
        public string PropertyName { get; private set; }
        public object OldValue { get; private set; }
        public object NewValue { get; set; }
    }