c# - 帮助使用 NHibernate 映射类对象列表

标签 c# .net nhibernate nhibernate-mapping propertygrid

我有一个包含对象列表的类。

我以前将其作为 IList 类型，映射得很好。但是，我想添加通过 PropertyGrid 控件添加/删除/编辑此列表中的项目的功能。

因此，我需要将 List 设置为从 CollectionBase 派生的 Collection 类型，并且包含 ICustomTypeDescriptor 才能使其正常工作，而不是原始 IList。

我在想是否有人可以告诉我如何操作，或者是否可以使用此方法映射此列表，或者我如何修改当前的方法以通过 PropertyGrid 使列表中的项目可编辑。

这是我的 CollectionClass，我还想弄清楚如何使其通用，以便我可以重用它，但尽管如此，这里还是我必须定义的两个类，以便通过属性网格:

public class ZoneCollection : CollectionBase, ICustomTypeDescriptor
{
    #region Collection Implementation

    /// <summary>
    /// Adds an zone object to the collection
    /// </summary>
    /// <param name="emp"></param>
    public void Add(Zone zone)
    {
        this.List.Add(zone);
    }

    /// <summary>
    /// Removes an zone object from the collection
    /// </summary>
    /// <param name="emp"></param>
    public void Remove(Zone zone)
    {
        this.List.Remove(zone);
    }

    /// <summary>
    /// Returns an employee object at index position.
    /// </summary>
    public Zone this[int index]
    {
        get
        {
            return (Zone)this.List[index];
        }
    }

    #endregion

    // Implementation of interface ICustomTypeDescriptor 
    #region ICustomTypeDescriptor impl

    public String GetClassName()
    {
        return TypeDescriptor.GetClassName(this, true);
    }

    public AttributeCollection GetAttributes()
    {
        return TypeDescriptor.GetAttributes(this, true);
    }

    public String GetComponentName()
    {
        return TypeDescriptor.GetComponentName(this, true);
    }

    public TypeConverter GetConverter()
    {
        return TypeDescriptor.GetConverter(this, true);
    }

    public EventDescriptor GetDefaultEvent()
    {
        return TypeDescriptor.GetDefaultEvent(this, true);
    }

    public PropertyDescriptor GetDefaultProperty()
    {
        return TypeDescriptor.GetDefaultProperty(this, true);
    }

    public object GetEditor(Type editorBaseType)
    {
        return TypeDescriptor.GetEditor(this, editorBaseType, true);
    }

    public EventDescriptorCollection GetEvents(Attribute[] attributes)
    {
        return TypeDescriptor.GetEvents(this, attributes, true);
    }

    public EventDescriptorCollection GetEvents()
    {
        return TypeDescriptor.GetEvents(this, true);
    }

    public object GetPropertyOwner(PropertyDescriptor pd)
    {
        return this;
    }


    /// <summary>
    /// Called to get the properties of this type. Returns properties with certain
    /// attributes. this restriction is not implemented here.
    /// </summary>
    /// <param name="attributes"></param>
    /// <returns></returns>
    public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
    {
        return GetProperties();
    }

    /// <summary>
    /// Called to get the properties of this type.
    /// </summary>
    /// <returns></returns>
    public PropertyDescriptorCollection GetProperties()
    {
        // Create a collection object to hold property descriptors
        PropertyDescriptorCollection pds = new PropertyDescriptorCollection(null);

        // Iterate the list of employees
        for (int i = 0; i < this.List.Count; i++)
        {
            // Create a property descriptor for the employee item and add to the property descriptor collection
            ZoneCollectionPropertyDescriptor pd = new ZoneCollectionPropertyDescriptor(this, i);
            pds.Add(pd);
        }
        // return the property descriptor collection
        return pds;
    }

    #endregion
}

/// <summary>
/// Summary description for CollectionPropertyDescriptor.
/// </summary>
public class ZoneCollectionPropertyDescriptor : PropertyDescriptor
{
    private ZoneCollection collection = null;
    private int index = -1;

    public ZoneCollectionPropertyDescriptor(ZoneCollection coll, int idx) :
        base("#" + idx.ToString(), null)
    {
        this.collection = coll;
        this.index = idx;
    }

    public override AttributeCollection Attributes
    {
        get
        {
            return new AttributeCollection(null);
        }
    }

    public override bool CanResetValue(object component)
    {
        return true;
    }

    public override Type ComponentType
    {
        get
        {
            return this.collection.GetType();
        }
    }

    public override string DisplayName
    {
        get
        {
            Zone zone = this.collection[index];
            return zone.ID.ToString();
        }
    }

    public override string Description
    {
        get
        {
            Zone zone = this.collection[index];
            StringBuilder sb = new StringBuilder();
            sb.Append(zone.ID.ToString());

            if ( zone.Streets.Route != String.Empty || zone.Streets.Crossing != String.Empty)
                sb.Append("::");
            if (zone.Streets.Route != String.Empty)
                sb.Append(zone.Streets.Route);
            if ( zone.Streets.Crossing != String.Empty)
            {
                sb.Append(" and ");
                sb.Append(zone.Streets.Crossing);
            }

            return sb.ToString();
        }
    }

    public override object GetValue(object component)
    {
        return this.collection[index];
    }

    public override bool IsReadOnly
    {
        get { return false; }
    }

    public override string Name
    {
        get { return "#" + index.ToString(); }
    }

    public override Type PropertyType
    {
        get { return this.collection[index].GetType(); }
    }

    public override void ResetValue(object component)
    {
    }

    public override bool ShouldSerializeValue(object component)
    {
        return true;
    }

    public override void SetValue(object component, object value)
    {
        // this.collection[index] = value;
    }
}

这是我的区域类:

[ComVisible(true)]
[TypeConverter(typeof(ExpandableObjectConverter))]
[CategoryAttribute("Configuration")]
[Serializable]
public class Zone
{
    #region Private Fields

    private bool active;
    private string dir;
    private Heading heading = new Heading();
    private int id;
    private int intID;
    private Position start = new Position();
    private Position finish = new Position();
    private int width;
    private Position[] corners = new Position[4];
    private Streets streets = new Streets();

    #endregion        

    #region Constructors

    public Zone() 
    {
        if (Program.main != null)
        {
            IntID = Program.main.intID;

            Intersection intersection = Program.data.Intersections.list.Find(
                delegate(Intersection tInt)
                {
                    return tInt.ID == IntID;
                }
            );

            if (intersection != null)
            {
                Streets.Crossing = intersection.Streets.Crossing;
                Streets.Route = intersection.Streets.Route;
            }
        }
    }

    #endregion

    #region Properties

    public virtual long PK { get; set; }

    [Browsable(false)]
    public virtual bool Active
    {
        get { return active; }
        set { active = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The direction for the Zone.")]
    public virtual string Dir
    {
        get { return dir; }
        set { dir = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The heading for the Zone.")]
    public virtual Heading Heading
    {
        get { return heading; }
        set { heading = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The Zone Identification Number.")]
    public virtual int ID
    {
        get { return id; }
        set { id = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The Identification Number associated with the Priority Detector of the Zone.")]
    public virtual int IntID
    {
        get { return intID; }
        set { intID = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The location of the Zone's Start.")]
    public virtual Position Start
    {
        get { return start; }
        set { start = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The location of the Zone's Finish.")]
    public virtual Position Finish
    {
        get { return finish; }
        set { finish = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The width of the Zone.")]
    public virtual int Width
    {
        get { return width; }
        set { width = value; }
    }

    [Browsable(false)]
    public virtual Position[] Corners
    {
        get { return corners; }
        set { corners = value; }
    }

    [CategoryAttribute("Configuration"),
        DescriptionAttribute("The streets associated with the Zone."),
        DisplayName("Zone Streets")]
    public virtual Streets Streets
    {
        get { return streets; }
        set { streets = value; }
    }

    #endregion
}

这是我的 Intersection 类中包含的 Zone 类对象列表的原始映射:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class xmlns="urn:nhibernate-mapping-2.2" name="EMTRAC.Devices.Device, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Device`" lazy="false">
  <id name="PK" type="System.Int64, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
    <column name="PK" />
    <generator class="identity" />
  </id>
  <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="LocalConnection" lazy="false" cascade="all">
    <column name="LocalConnection_id" />
  </many-to-one>
  <many-to-one class="EMTRAC.Connections.Connection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Connection" lazy="false" cascade="all">
    <column name="Connection_id" />
  </many-to-one>
  <many-to-one class="EMTRAC.Packets.Packet, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Configuration" lazy="false" cascade="all">
    <column name="Configuration_id" />
  </many-to-one>
  <joined-subclass name="EMTRAC.Intersections.Intersection, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" lazy="false">
    <key>
      <column name="Device_id" />
    </key>
    <bag name="Zones" cascade="all-delete-orphan">
      <key>
        <column name="Intersection_id" />
      </key>
      <one-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
    </bag>
    <many-to-one class="EMTRAC.Intersections.Streets, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Streets" lazy="false" cascade="all">
      <column name="Streets_id" />
    </many-to-one>
    <many-to-one class="EMTRAC.Positions.Position, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Position" lazy="false" cascade="all">
      <column name="Position" />
    </many-to-one>
  </joined-subclass>
</class>

我最初使用了一个简单的包，因为我使用的是 IList，但我不确定现在要做什么或如何执行此操作，因为区域列表不是 IList，而是从 CollectionBase 派生的 ZoneCollection 类.

我认为它是呕吐b/c我没有映射出ZoneCollection类，但我不知道如何开始映射这个b/c所有类都是区域对象列表。我是否只映射类并在该类中放置一个包？

有什么建议吗？

最佳答案

回到这里以防其他人遇到这个问题。

我实际上能够实现我正在寻找的功能，但需要进行一些调整。

我偏离了使用 CustomCollection 实现的路线，而是使用了 IList 的通用和非通用实现，以便能够将集合与 NHibernate 完全映射，并将集合显示为基础的属性可通过集合编辑器编辑的类。

映射本身非常简单。我们简单地定义一个组件，将访问指定为属性。在组件中，我们定义包名称，并将包的访问权限设置为字段。我还建议将级联选项设置为“all-delete-orphan”。最后，我们像平常一样使用键声明包，然后声明它包含的类。这是我的映射:

     <component name="Zones" access="property">
    <bag name="_list" cascade="all-delete-orphan" access="field" lazy="false">
      <key>
        <column name="Intersection_PK" />
      </key> 
      <one-to-many class="EMTRAC.Zones.Zone, EMTRAC_v3, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
    </bag>
  </component>

现在，棘手的部分。事实证明，属性网格对于它的期望非常挑剔。

您可能知道也可能不知道，映射一个实现 CollectionBase 的类对于 NHibernate 来说并不是一件小事。因此，我决定尝试通过实现 IList 来解决此方法，其中 Zone 是您存储在 Collection 中的对象类型。

事实证明，PropertyGrid 控件不喜欢这样。它需要非泛型 IList 显式实现，而不是泛型实现。我认为我的实现不会有问题，因为我在本例中指定了特定类型；然而，我错了。

事实证明我可以实现通用和非通用 IList，这解决了我所有的问题。现在，我可以使用 NHibernate 映射集合，在 PropertyGrid 控件中显示属性，并通过单击 PropertyGrid 控件中的集合时自动打开的 CollectionEditor 编辑集合。这是我对 Collection 类的实现:

    public class ZoneCollection : IList<Zone>, IList, ICustomTypeDescriptor
{
    private IList<Zone> _list = new List<Zone>();

    //private IList _list = new ArrayList();

    public ZoneCollection()
    {
        //_list = new ArrayList();
    }

    public int IndexOf(Zone item)
    {
        return _list.IndexOf(item);
    }

    public void Insert(int index, Zone item)
    {
        _list.Insert(index, item);
    }

    public void RemoveAt(int index)
    {
        _list.RemoveAt(index);
    }

    public Zone this[int index]
    {
        get
        {
            return _list[index];
        }
        set
        {
            _list[index] = value;
        }
    }

    public void Add(Zone item)
    {
        _list.Add(item);
    }

    public void Clear()
    {
        _list.Clear();
    }

    public bool Contains(Zone item)
    {
        return _list.Contains(item);
    }

    public void CopyTo(Zone[] array, int arrayIndex)
    {
        _list.CopyTo(array, arrayIndex);
    }

    public int Count
    {
        get { return _list.Count; }
    }

    public bool IsReadOnly
    {
        get { return ((IList)_list).IsReadOnly; }
    }

    public bool Remove(Zone item)
    {
        return _list.Remove(item);
    }

    public IEnumerator<Zone> GetEnumerator()
    {
        return _list.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }

    int IList.Add(object value)
    {
        int index = Count;
        Add((Zone)value);
        return index;
    }

    bool IList.Contains(object value)
    {
        return Contains((Zone)value);
    }

    int IList.IndexOf(object value)
    {
        return IndexOf((Zone)value);
    }

    void IList.Insert(int index, object value)
    {
        Insert(index, (Zone)value);
    }

    bool IList.IsFixedSize
    {
        get { return ((IList)_list).IsFixedSize; }
    }

    bool IList.IsReadOnly
    {
        get { return ((IList)_list).IsReadOnly; }
    }

    void IList.Remove(object value)
    {
        Remove((Zone)value);
    }

    object IList.this[int index]
    {
        get
        {
            return this[index];
        }
        set
        {
            this[index] = (Zone)value;
        }
    }

    void ICollection.CopyTo(Array array, int index)
    {
        CopyTo((Zone[])array, index);
    }

    bool ICollection.IsSynchronized
    {
        get { return ((ICollection)_list).IsSynchronized; }
    }

    object ICollection.SyncRoot
    {
        get { return ((ICollection)_list).SyncRoot; }
    }


    // Implementation of interface ICustomTypeDescriptor 
    #region ICustomTypeDescriptor impl

    public String GetClassName()
    {
        return TypeDescriptor.GetClassName(this, true);
    }

    public AttributeCollection GetAttributes()
    {
        return TypeDescriptor.GetAttributes(this, true);
    }

    public String GetComponentName()
    {
        return TypeDescriptor.GetComponentName(this, true);
    }

    public TypeConverter GetConverter()
    {
        return TypeDescriptor.GetConverter(this, true);
    }

    public EventDescriptor GetDefaultEvent()
    {
        return TypeDescriptor.GetDefaultEvent(this, true);
    }

    public PropertyDescriptor GetDefaultProperty()
    {
        return TypeDescriptor.GetDefaultProperty(this, true);
    }

    public object GetEditor(Type editorBaseType)
    {
        return TypeDescriptor.GetEditor(this, editorBaseType, true);
    }

    public EventDescriptorCollection GetEvents(Attribute[] attributes)
    {
        return TypeDescriptor.GetEvents(this, attributes, true);
    }

    public EventDescriptorCollection GetEvents()
    {
        return TypeDescriptor.GetEvents(this, true);
    }

    public object GetPropertyOwner(PropertyDescriptor pd)
    {
        return this;
    }


    /// <summary>
    /// Called to get the properties of this type. Returns properties with certain
    /// attributes. this restriction is not implemented here.
    /// </summary>
    /// <param name="attributes"></param>
    /// <returns></returns>
    public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
    {
        return GetProperties();
    }

    /// <summary>
    /// Called to get the properties of this type.
    /// </summary>
    /// <returns></returns>
    public PropertyDescriptorCollection GetProperties()
    {
        // Create a collection object to hold property descriptors
        PropertyDescriptorCollection pds = new PropertyDescriptorCollection(null);

        // Iterate the list of zones
        for (int i = 0; i < this._list.Count; i++)
        {
            // Create a property descriptor for the zone item and add to the property descriptor collection
            ZoneCollectionPropertyDescriptor pd = new ZoneCollectionPropertyDescriptor(this, i);
            pds.Add(pd);
        }
        // return the property descriptor collection
        return pds;
    }

    #endregion
}

/// <summary>
/// Summary description for CollectionPropertyDescriptor.
/// </summary>
public class ZoneCollectionPropertyDescriptor : PropertyDescriptor
{
    private ZoneCollection collection = null;
    private int index = -1;

    public ZoneCollectionPropertyDescriptor(ZoneCollection coll, int idx) :
        base("#" + idx.ToString(), null)
    {
        this.collection = coll;
        this.index = idx;

    }

    public override AttributeCollection Attributes
    {
        get
        {
            return new AttributeCollection(null);
        }
    }

    public override bool CanResetValue(object component)
    {
        return true;
    }

    public override Type ComponentType
    {
        get
        {
            return this.collection.GetType();
        }
    }

    public override string DisplayName
    {
        get
        {
            Zone zone = (Zone)this.collection[index];
            return zone.ID.ToString();
        }
    }

    public override string Description
    {
        get
        {
            Zone zone = (Zone)this.collection[index];
            StringBuilder sb = new StringBuilder();
            sb.Append(zone.ID.ToString());

            if (zone.Streets.Route != String.Empty || zone.Streets.Crossing != String.Empty)
                sb.Append("::");
            if (zone.Streets.Route != String.Empty)
                sb.Append(zone.Streets.Route);
            if (zone.Streets.Crossing != String.Empty)
            {
                sb.Append(" and ");
                sb.Append(zone.Streets.Crossing);
            }

            return sb.ToString();
        }
    }

    public override object GetValue(object component)
    {
        return this.collection[index];
    }

    public override bool IsReadOnly
    {
        get { return false; }
    }

    public override string Name
    {
        get { return "#" + index.ToString(); }
    }

    public override Type PropertyType
    {
        get { return this.collection[index].GetType(); }
    }

    public override void ResetValue(object component)
    {
    }

    public override bool ShouldSerializeValue(object component)
    {
        return true;
    }

    public override void SetValue(object component, object value)
    {
        // this.collection[index] = value;
    }
}

特别感谢 Firo 让我走上了正确的道路，并感谢 Simon Mourier 帮助我澄清了剩下的事情。希望其他人将来可以从中受益。

关于c# - 帮助使用 NHibernate 映射类对象列表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/7419980/

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