一个对象集合排序的类

写了一个对象集合排序的类

废话不多说，首先是定义一个对象实体类

    class Entity
    {
        public Entity()
        {}
        private int id;
        public int Id
        {
            get
            {
                return id;
            }
            set
            {
                id = value;
            }
        }
        private string name;
        public string Name
        {
            get
            {
                return name;
            }
            set
            {
                name = value;
            }
        }

        private double price;
        public double Price
        {
            get
            {
                return price;
            }
            set
            {
                price = value;
            }
        }
    }

然后写一个对象比较的类，实现IComparer<T>接口。

    internal class ListComparer<TBaseBusinessObject> : IComparer<TBaseBusinessObject>
    {
        private string propertyName;

        public ListComparer(string PropertyName)
        {
            propertyName = PropertyName;
        }
        

        IComparer Members#region IComparer<TBaseBusinessObject> Members

        public int Compare(TBaseBusinessObject x, TBaseBusinessObject y)
        {
            PropertyInfo property = typeof(TBaseBusinessObject).GetProperty(propertyName);
            if (property.PropertyType == Type.GetType("System.Int16"))
            {
                int xNumber = 0;
                int yNumber = 0;
                if (property.GetValue(x, null) != null)
                {
                    xNumber = Convert.ToInt16(property.GetValue(x, null).ToString());
                }
                if (property.GetValue(y, null) != null)
                {
                    yNumber = Convert.ToInt16(property.GetValue(y, null).ToString());
                }
                return xNumber.CompareTo(yNumber);
            }
            if (property.PropertyType == Type.GetType("System.Int32"))
            {
                int xNumber = 0;
                int yNumber = 0;
                if (property.GetValue(x, null) != null)
                {
                    xNumber = Convert.ToInt32(property.GetValue(x, null).ToString());
                }
                if (property.GetValue(y, null) != null)
                {
                    yNumber = Convert.ToInt32(property.GetValue(y, null).ToString());
                }
                return xNumber.CompareTo(yNumber);
            }
            if (property.PropertyType == Type.GetType("System.Double"))
            {
                double xNumber = 0;
                double yNumber = 0;
                if (property.GetValue(x, null) != null)
                {
                    xNumber = Convert.ToDouble(property.GetValue(x, null).ToString());
                }
                if (property.GetValue(y, null) != null)
                {
                    yNumber = Convert.ToDouble(property.GetValue(y, null).ToString());
                }
                return xNumber.CompareTo(yNumber);
            }
            if (property.PropertyType == Type.GetType("System.DateTime"))
            {
                DateTime xTime = DateTime.Now;
                DateTime yTime = DateTime.Now;
                if (property.GetValue(x, null) != null)
                {
                    xTime = Convert.ToDateTime(property.GetValue(x, null).ToString());
                }
                if (property.GetValue(y, null) != null)
                {
                    yTime = Convert.ToDateTime(property.GetValue(y, null).ToString());
                }
                return xTime.CompareTo(yTime);
            }
            if ((property.PropertyType == Type.GetType("System.String")) || (property.PropertyType == Type.GetType("System.Boolean")))
            {
                string xText = string.Empty;
                string yText = string.Empty;
                if (property.GetValue(x, null) != null)
                {
                    xText = property.GetValue(x, null).ToString();
                }
                if (property.GetValue(y, null) != null)
                {
                    yText = property.GetValue(y, null).ToString();
                }
                return xText.CompareTo(yText);
            }
            return 0;

        }

        #endregion
    }

然后是写了一个List继承List<T>类的集合，

    public class BaseBusinessObjectList<TBaseBusinessObject> : List<TBaseBusinessObject>
    {
        public void Sort(string sortfield, bool isAscending)
        {
            //这里实例化了刚才写的IComparer类。
            ListComparer<TBaseBusinessObject> listComparer = new ListComparer<TBaseBusinessObject>(sortfield);
            base.Sort(listComparer);
            if (!isAscending) base.Reverse();
        }
    }

于是就写完了，用的时候

    BaseBusinessObjectList<Entity> list = new BaseBusinessObjectList<Entity>();
    Entity obj = new Entity();
    obj.Id = 1;
    obj.Name = "test";
    obj.Price = 3.23;
    list.Add(obj);

    //按照Name字段向上排序。
    list.Sort("Name",true);
    //按照Price字段向上排序。
    list.Sort("Price",true);
    //按照Id字段向下排序。
    list.Sort("Id",false);

完了~~~