当孩子发生变化时更新父母[重复]

Question

父集合绑定到具有分层gridview结构的radGridView。

有没有办法在内部集合发生变化时触发父属性

父对象：

    public class CoverHierarchical : EditableModelBase<CoverHierarchical>
    {
        #region Attribute Declarations

        private Int32 m_iId;
        private string m_sName = "";
        private bool m_bIsChanged;
        private ObservableCollection<CoverContentBO> m_oCoverContent;

        #endregion

        /// <summary>
        /// Get or set the id.
        /// </summary> 
        public Int32 Id
        {
            get { return this.m_iId; }

            set
            {
                if (this.m_iId != value)
                {
                    this.IsChanged = true;
                    this.m_iId = value;
                    RaisePropertyChanged("Id");
                }
            }
        }

        /// <summary>
        /// Get or set the name.
        /// </summary> 
        public string Name
        {
            get { return this.m_sName; }

            set
            {
                if (this.m_sName != value)
                {
                    this.IsChanged = true;
                    this.m_sName = value;
                    RaisePropertyChanged("Name");
                }
            }
        }


        /// <summary>
        /// Get or set the CoverContent Collection.
        /// </summary> 
        public ObservableCollection<CoverContentBO> CoverContentCollection
        {
            get { return this.m_oCoverContent; }

            set
            {
                if (this.m_oCoverContent != value)
                {
                    this.IsChanged = true;
                    this.m_oCoverContent = value;
                    RaisePropertyChanged("CoverContentCollection");
                }
            }
        }


        /// <summary>
        /// Get or set the changed flag.
        /// </summary>
        public bool IsChanged
        {
            get { return this.m_bIsChanged || this.CoverContentCollection.Any(i=>i.IsChanged); }

            set
            {
                if (this.m_bIsChanged != value)
                {
                    this.m_bIsChanged = value;
                    RaisePropertyChanged("IsChanged");
                }
            }
        }

        #endregion
  }

和子对象

        [Serializable]
    public class CoverContentBO : EditableModelBase<CoverContentBO>
    {
        #region Attribute Declarations

        private Int32 m_iCoverId;
        private Int32 m_iId;
        private bool m_bIsChanged;


        #endregion

        #region Public Properties

        /// <summary>
        /// Get or set the cover id.
        /// </summary> 
        public Int32 CoverId
        {
            get { return this.m_iCoverId; }

            set
            {
                if (this.m_iCoverId != value)
                {
                    this.IsChanged = true;
                    this.m_iCoverId = value;
                    RaisePropertyChanged("CoverId");
                }
            }
        }

        /// <summary>
        /// Get or set the id.
        /// </summary> 
        public Int32 Id
        {
            get { return this.m_iId; }

            set
            {
                if (this.m_iId != value)
                {
                    this.IsChanged = true;
                    this.m_iId = value;
                    RaisePropertyChanged("Id");
                }
            }
        }



        /// <summary>
        /// Get or set the changed flag.
        /// </summary>
        public bool IsChanged
        {
            get { return this.m_bIsChanged; }

            set
            {
                if (this.m_bIsChanged != value)
                {
                    this.m_bIsChanged = value;
                    RaisePropertyChanged("IsChanged");
                }
            }
        }

     #endregion

   }

在 ViewModel 中

public ObservableCollection<CoverHierarchical> CoverHierarchicalCollection
    {
        get { return m_CoverHierarchicalCollection; }
        set
        {
            if (m_CoverHierarchicalCollection != value)
            {
                m_CoverHierarchicalCollection = value;
                OnPropertyChanged();
            }
        }
    }

CoverHierarchicalCollection 绑定到视图。如果用户编辑子网格，则更改发生在子网格中。在更改子内部集合（CoverContentCollection）字段时，有什么方法可以触发父级的IsChanged 属性。

Answer 1

您可以像下面这样收听子级的PropertyChanged 和CollectionChanged 并更新父级的IsChanged

    /// <summary>
    /// Get or set the CoverContent Collection.
    /// </summary> 
    public ObservableCollection<CoverContentBO> CoverContentCollection
    {
        get { return this.m_oCoverContent; }

        set
        {
            if (this.m_oCoverContent != value)
            {
                this.IsChanged = true;

                RemoveEventhandlers(m_oCoverContent);

                this.m_oCoverContent = value;

                AddEventhandlers(m_oCoverContent);
                RaisePropertyChanged("CoverContentCollection");
            }
        }
    }

    private void AddEventhandlers(ObservableCollection<CoverContentBO> oCoverContent)
    {
        foreach (var CoverContentBO in oCoverContent)
        {
            CoverContentBO.PropertyChanged +=CoverContentBO_PropertyChanged;
        }

        oCoverContent.CollectionChanged +=oCoverContent_CollectionChanged;
    }

    void oCoverContent_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        foreach (CoverContentBO CoverContentBO in e.OldItems)
        {
            CoverContentBO.PropertyChanged -=CoverContentBO_PropertyChanged;
        }

        foreach (CoverContentBO CoverContentBO in e.NewItems)
        {
            CoverContentBO.PropertyChanged +=CoverContentBO_PropertyChanged;
        }
    }

    void CoverContentBO_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName == "IsChanged")
        {
            IsChanged = true;
        }
    }

    private void RemoveEventhandlers(ObservableCollection<CoverContentBO> oCoverContent)
    {
        foreach (var CoverContentBO in oCoverContent)
        {
            CoverContentBO.PropertyChanged -=CoverContentBO_PropertyChanged;
        }

        oCoverContent.CollectionChanged -=oCoverContent_CollectionChanged;
    }