DataTable转换成IList

冷不防 2022-03-20 08:38 208阅读 0赞

**[作者：陈太汉][Link 1]**

**[DataTable转换成IList][Link 1]**

**在用C\#作开发的时候经常要把DataTable转换成IList；操作DataTable比较麻烦，把DataTable转换成IList，以对象实体作为IList的元素，操作起来就非常方便。**

**注意：实体的属性必须和数据库中的字段必须一一对应，或者数据库字段名.ToLower().Contains(实体属性名.ToLower())**

**          数据类型暂时至支持int、string、DateTime、float、double**

** **

using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.Data;
    using System.Reflection;
    
    namespace TBToListTest
    {
        public class TBToList<T> where T : new()
        {
            /// <summary>
            /// 获取列名集合
            /// </summary>
            private IList<string> GetColumnNames(DataColumnCollection dcc)
            {
                IList<string> list = new List<string>();
                foreach (DataColumn dc in dcc)
                {
                    list.Add(dc.ColumnName);
                }
                return list;
            }
    
            /// <summary>
            ///属性名称和类型名的键值对集合
            /// </summary>
            private Hashtable GetColumnType(DataColumnCollection dcc)
            {
                if (dcc == null || dcc.Count == 0)
                {
                    return null;
                }
                IList<string> colNameList = GetColumnNames(dcc);
    
                Type t = typeof(T);
                PropertyInfo[] properties = t.GetProperties();
                Hashtable hashtable = new Hashtable();
                int i = 0;
                foreach (PropertyInfo p in properties)
                {
                    foreach (string col in colNameList)
                    {
                        if (col.ToLower().Contains(p.Name.ToLower()))
                        {
                            hashtable.Add(col, p.PropertyType.ToString() + i++);
                        }
                    }
                }
    
                return hashtable;
            }
    
            /// <summary>
            /// DataTable转换成IList
            /// </summary>
            /// <param name="dt"></param>
            /// <returns></returns>
            public IList<T> ToList(DataTable dt)
            {
                if (dt == null || dt.Rows.Count == 0)
                {
                    return null;
                }
    
                PropertyInfo[] properties = typeof(T).GetProperties();//获取实体类型的属性集合
                Hashtable hh = GetColumnType(dt.Columns);//属性名称和类型名的键值对集合
                IList<string> colNames = GetColumnNames(hh);//按照属性顺序的列名集合
                List<T> list = new List<T>();
                T model = default(T);
                foreach (DataRow dr in dt.Rows)
                {
                    model = new T();//创建实体
                    int i = 0;
                    foreach (PropertyInfo p in properties)
                    {
                        if (p.PropertyType == typeof(string))
                        {
                            p.SetValue(model, dr[colNames[i++]], null);
                        }
                        else if (p.PropertyType == typeof(int))
                        {
                            p.SetValue(model, int.Parse(dr[colNames[i++]].ToString()), null);
                        }
                        else if (p.PropertyType == typeof(DateTime))
                        {
                            p.SetValue(model, DateTime.Parse(dr[colNames[i++]].ToString()), null);
                        }
                        else if (p.PropertyType == typeof(float))
                        {
                            p.SetValue(model, float.Parse(dr[colNames[i++]].ToString()), null);
                        }
                        else if (p.PropertyType == typeof(double))
                        {
                            p.SetValue(model, double.Parse(dr[colNames[i++]].ToString()), null);
                        }
                    }
    
                    list.Add(model);
                }
    
                return list;
            }
    
            /// <summary>
            /// 按照属性顺序的列名集合
            /// </summary>
            private IList<string> GetColumnNames(Hashtable hh)
            {
                PropertyInfo[] properties = typeof(T).GetProperties();//获取实体类型的属性集合
                IList<string> ilist = new List<string>();
                int i = 0;
                foreach (PropertyInfo p in properties)
                {
                    ilist.Add(GetKey(p.PropertyType.ToString() + i++, hh));
                }
                return ilist;
            }
    
            /// <summary>
            /// 根据Value查找Key
            /// </summary>
            private string GetKey(string val, Hashtable tb)
            {
                foreach (DictionaryEntry de in tb)
                {
                    if (de.Value.ToString() == val)
                    {
                        return de.Key.ToString();
                    }
                }
                return null;
            }
              
        }
    }
    
    
    
    
    
    
    
    
    namespace TBToListTest
    {
    
       //实体
        public class Person
        {
            public int ID
            {
                set;
                get;
            }
    
            public string Name
            {
                set;
                get;
            }
    
            public string Age
            {
                set;
                get;
            }
    
            public string Lover
            {
                set;
                get;
            }
    
        }
    }
    
    
    
    
    using System;
    using System.Data;
    
    namespace TBToListTest
    {
        class Program
        {
            static void Main(string[] args)
            {
                TBToList<Person> tol = new TBToList<Person>();
                Console.WriteLine();
                DataTable dt =  GetTable();
                tol.ToList(dt);
                Console.Read();
            }
    
            public static DataTable GetTable()
            {
                DataTable dt = new DataTable();
                dt.Columns.Add("ID");
                dt.Columns.Add("Age");
                dt.Columns.Add("Lover");
                dt.Columns.Add("Name");
                DataRow dr = dt.NewRow();
                dr["ID"] = 1;
                dr["Age"] = "Age1";
                dr["Lover"] = "Lover1";
                dr["Name"] = "Name1";
                dt.Rows.Add(dr);
                DataRow dr1 = dt.NewRow();
                dr1["ID"] = 2;
                dr1["Age"] = "Age2";
                dr1["Lover"] = "Lover2";
                dr1["Name"] = "Name2";
                dt.Rows.Add(dr1);
                return dt;
            }
        }
    }

作者： [陈太汉][Link 2]  
出处： [http://hlxs.cnblogs.com/][Link 2]  
本文版权归作者和博客园共有，欢迎转载

[Link 1]: http://blog.csdn.net/chentaihan
[Link 2]: http://www.cnblogs.com/hlxs/