将 IList<T> 或 IList 转换为Dataset或DataTable

通过 NHibernate 查询返回的表数据通常都是IList<T>，但在实际使用中有些数据控件在数据绑定上对IList的支持并不是很好，所以有时候将IList转换成DataSet还是有必要的。

将IList<T>转换成Dataset或DataTable

        /// <summary>
        /// Ilist<T> 转换成 DataSet
        /// </summary>
        /// <param name="list"></param>
        /// <returns></returns>
        public static DataSet ConvertToDataSet<T>(IList<T> i_objlist)
        {
            if (i_objlist == null || i_objlist.Count <= 0)
            {
                return null;
            }

            DataSet ds = new DataSet();
            DataTable dt = new DataTable(typeof(T).Name);
            DataColumn column;
            DataRow row;

            System.Reflection.PropertyInfo[] myPropertyInfo = typeof(T).GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);
            foreach (T t in i_objlist)
            {
                if (t == null)
                {
                    continue;
                }

                row = dt.NewRow();

                for (int i = 0, j = myPropertyInfo.Length; i < j; i++)
                {
                    System.Reflection.PropertyInfo pi = myPropertyInfo[i];

                    string name = pi.Name;

                    Type colType = pi.PropertyType;

                    if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition()== typeof(Nullable<>)))
                    {
                        colType = colType.GetGenericArguments()[0];
                    }


                    if (dt.Columns[name] == null)
                    {
                        column = new DataColumn(name, colType);
                        dt.Columns.Add(column);
                    }

                    row[name] = pi.GetValue(t, null) == null ? DBNull.Value : pi.GetValue(t,null);
                }

                dt.Rows.Add(row);
            }

            ds.Tables.Add(dt);

            return ds;
        }

        /// <summary>
        /// Ilist<T> 转换成 DataTable
        /// </summary>
        /// <param name="list"></param>
        /// <returns></returns>
        public static DataTable ConvertToDataTable<T>(IList<T> i_objlist)
        {
            if (i_objlist == null || i_objlist.Count <= 0)
            {
                return null;
            }
            DataTable dt = new DataTable(typeof(T).Name);
            DataColumn column;
            DataRow row;

            System.Reflection.PropertyInfo[] myPropertyInfo = typeof(T).GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance);

            foreach (T t in i_objlist)
            {
                if (t == null)
                {
                    continue;
                }

                row = dt.NewRow();

                for (int i = 0, j = myPropertyInfo.Length; i < j; i++)
                {
                    System.Reflection.PropertyInfo pi = myPropertyInfo[i];

                    string name = pi.Name;

                    Type colType = pi.PropertyType;

                    if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                    {
                        colType = colType.GetGenericArguments()[0];
                    }

                    if (dt.Columns[name] == null)
                    {
                        column = new DataColumn(name, colType);
                        dt.Columns.Add(column);
                    }

                    row[name] = pi.GetValue(t, null) == null ? DBNull.Value : pi.GetValue(t, null);
                }

                dt.Rows.Add(row);
            }
            return dt;
        }

 

 

将IList转换成Dataset或DataTable

...

 

IList<T>的排序:

C# code:

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;

namespace Business.common
{
    /// <summary>
    /// IList排序类
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class IListSort<T>
    {
        private string _propertyName;
        private bool _sortBy = true;
        private IList<T> _list;

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="list">排序的Ilist</param>
        /// <param name="propertyName">排序字段属性名</param>
        /// <param name="sortBy">true升序 false 降序 不指定则为true</param>
        public IListSort(IList<T> list, string propertyName, bool sortBy)
        {
            _list = list;
            _propertyName = propertyName;
            _sortBy = sortBy;
        }
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="list">排序的Ilist</param>
        /// <param name="propertyName">排序字段属性名</param>
        /// <param name="sortBy">true升序 false 降序 不指定则为true</param>
        public IListSort(IList<T> list, string propertyName)
        {
            _list = list;
            _propertyName = propertyName;
            _sortBy = true;
        }

        /// <summary>
        /// IList
        /// </summary>
        public IList<T> List
        {
            get { return _list; }
            set { _list = value; }
        }

        /// <summary>
        /// 排序字段属性名
        /// </summary>
        public string PropertyName
        {
            get { return _propertyName; }
            set { _propertyName = value; }
        }

        /// <summary>
        /// true升序 false 降序
        /// </summary>
        public bool SortBy
        {
            get { return _sortBy; }
            set { _sortBy = value;}
        }

        /// <summary>
        /// 排序，插入排序方法
        /// </summary>
        /// <returns></returns>
        public IList<T> Sort()
        {
            if (_list.Count == 0) return _list;
            for (int i = 1; i < _list.Count; i++) {
                T t = _list[i];
                int j = i;
                while ((j > 0) && Compare(_list[j - 1], t) < 0) {
                    _list[j] = _list[j - 1];
                    --j;
                }
                _list[j] = t;
            }
            return _list;
        }
       
        /// <summary>
        /// 比较大小 返回值 小于零则X小于Y，等于零则X等于Y，大于零则X大于Y
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        private int Compare(T x, T y)
        {
            if (string.IsNullOrEmpty(_propertyName)) throw new ArgumentNullException("没有指字对象的排序字段属性名!");
            PropertyInfo property = typeof( T ).GetProperty(_propertyName);
            if (property == null) throw new ArgumentNullException("在对象中没有找到指定属性!");

            switch (property.PropertyType.ToString()) {
                case "System.Int32" :
                    int int1 = 0;
                    int int2 = 0;
                    if (property.GetValue(x, null) != null) {
                        int1 = Convert.ToInt32(property.GetValue(x, null));
                    }
                    if (property.GetValue(y, null) != null) {
                        int2 = Convert.ToInt32(property.GetValue(y, null));
                    }
                    if (_sortBy) {
                        return int2.CompareTo(int1);
                    }
                    else {
                        return int1.CompareTo(int2);
                    }
                    break;
                case "System.Double":
                    double double1 = 0;
                    double double2 = 0;
                    if (property.GetValue(x, null) != null) {
                        double1 = Convert.ToDouble(property.GetValue(x, null));
                    }
                    if (property.GetValue(y, null) != null) {
                        double2 = Convert.ToDouble(property.GetValue(y, null));
                    }
                    if (_sortBy) {
                        return double2.CompareTo(double1);
                    }
                    else {
                        return double1.CompareTo(double2);
                    }
                    break;
                case "System.String" :
                    string string1 = string.Empty;
                    string string2 = string.Empty;
                    if (property.GetValue(x, null) != null) {
                        string1 = property.GetValue(x, null).ToString();
                    }
                    if (property.GetValue(y, null) != null) {
                        string2 = property.GetValue(y, null).ToString();
                    }
                    if (_sortBy) {
                        return string2.CompareTo(string1);
                    }
                    else {
                        return string1.CompareTo(string2);
                    }
                    break;
                case "System.DateTime":
                    DateTime DateTime1 = DateTime.Now;
                    DateTime DateTime2 = DateTime.Now;
                    if (property.GetValue(x, null) != null) {
                        DateTime1 = Convert.ToDateTime(property.GetValue(x, null));
                    }
                    if (property.GetValue(y, null) != null) {
                        DateTime2 = Convert.ToDateTime(property.GetValue(y, null));
                    }
                    if (_sortBy) {
                        return DateTime2.CompareTo(DateTime1);
                    }
                    else {
                        return DateTime1.CompareTo(DateTime2);
                    }
                    break;
            }
            return 0;
        }
    }
}

调用：


            IList<MVote> list=new MVoteClassDAL().lazilyLoad(int.Parse(Request.QueryString["Id"])).M_Votes;  
            this.GridView1.DataSource = new IListSort<MVote>(list, "SortOrder").Sort();
            this.GridView1.DataBind();