C#中Datatable和List互相转换

　　其实早就该写的，哈哈，不过今天刚想起来注册，热热手，就写一下，哈哈。

　　直接上内容吧：

　　建立一个控制台应用程序，

             List<students> Studentlist =
             new List<students>{
                 new students{ Name = "zhagnsan1", Chinese = , Math = , English =  },
                 new students{ Name = "zhagnsan2", Chinese = , Math = , English =  },
                 new students{ Name = "zhagnsan3", Chinese = , Math = , English =  }
             };
             DataTable dt = ListToDatatableHelper.ToDataTable(Studentlist);
             this.dataGridView1.DataSource = dt;

             List<students> list = DatatableToListHelper.ConvertToList(dt);

         　　public class students
         　　{
             public string Name { get; set; }
             public double English { get; set; }
             public double Chinese { get; set; }
             public double Math { get; set; }
         　　}

　　ListToDatatableHelper.cs中的内容为：

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Linq;
 using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;

 namespace ListToDatatable
 {
     public class ListToDatatableHelper
     {
         /// <summary>
         /// Convert a List{T} to a DataTable.
         /// </summary>
         public static DataTable ToDataTable<T>(List<T> items)
         {
             var tb = new DataTable(typeof(T).Name);

             PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);

             foreach (PropertyInfo prop in props)
             {
                 Type t = GetCoreType(prop.PropertyType);
                 tb.Columns.Add(prop.Name, t);
             }

             foreach (T item in items)
             {
                 var values = new object[props.Length];

                 for (int i = ; i < props.Length; i++)
                 {
                     values[i] = props[i].GetValue(item, null);
                 }

                 tb.Rows.Add(values);
             }

             return tb;
         }

         /// <summary>
         /// Determine of specified type is nullable
         /// </summary>
         public static bool IsNullable(Type t)
         {
             return !t.IsValueType || (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>));
         }

         /// <summary>
         /// Return underlying type if type is Nullable otherwise return the type
         /// </summary>
         public static Type GetCoreType(Type t)
         {
             if (t != null && IsNullable(t))
             {
                 if (!t.IsValueType)
                 {
                     return t;
                 }
                 else
                 {
                     return Nullable.GetUnderlyingType(t);
                 }
             }
             else
             {
                 return t;
             }
         }

         //*************************************************
         /// <summary>
         /// List转Datatable
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="table"></param>
         /// <returns></returns>
         public static IList<T> ConvertTo<T>(DataTable table)
         {
             if (table == null)
             {
                 return null;
             }

             List<DataRow> rows = new List<DataRow>();

             foreach (DataRow row in table.Rows)
             {
                 rows.Add(row);
             }

             return ConvertTo<T>(rows);
         }

         public static IList<T> ConvertTo<T>(IList<DataRow> rows)
         {
             IList<T> list = null;

             if (rows != null)
             {
                 list = new List<T>();

                 foreach (DataRow row in rows)
                 {
                     T item = CreateItem<T>(row);
                     list.Add(item);
                 }
             }

             return list;
         }

         public static T CreateItem<T>(DataRow row)
         {
             T obj = default(T);
             if (row != null)
             {
                 obj = Activator.CreateInstance<T>();

                 foreach (DataColumn column in row.Table.Columns)
                 {
                     PropertyInfo prop = obj.GetType().GetProperty(column.ColumnName);
                     try
                     {
                         object value = row[column.ColumnName];
                         prop.SetValue(obj, value, null);
                     }
                     catch
                     {  //You can log something here
                        //throw;
                     }
                 }
             }

             return obj;
         }
     }
 }

　　DatatableToListHelper.cs中的内容为：

 using NPOI.SS.Formula.Functions;
 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Linq;
 using System.Reflection;
 using System.Text;
 using System.Threading.Tasks;
 using static ListToDatatable.Form1;

 namespace ListToDatatable
 {
     class DatatableToListHelper
     {
         /// <summary>
         /// 利用反射和泛型
         /// </summary>
         /// <param name="dt"></param>
         /// <returns></returns>
         public static List<students> ConvertToList(DataTable dt)
         {
             // 定义集合
             List<students> ts = new List<students>();

             // 获得此模型的类型
             Type type = typeof(students);
             //定义一个临时变量
             string tempName = string.Empty;
             //遍历DataTable中所有的数据行
             foreach (DataRow dr in dt.Rows)
             {
                 students t = new students();
                 // 获得此模型的公共属性
                 PropertyInfo[] propertys = t.GetType().GetProperties();
                 //遍历该对象的所有属性
                 foreach (PropertyInfo pi in propertys)
                 {
                     tempName = pi.Name;//将属性名称赋值给临时变量
                     //检查DataTable是否包含此列（列名==对象的属性名）
                     if (dt.Columns.Contains(tempName))
                     {
                         // 判断此属性是否有Setter
                         if (!pi.CanWrite) continue;//该属性不可写，直接跳出
                         //取值
                         object value = dr[tempName];
                         //如果非空，则赋给对象的属性
                         if (value != DBNull.Value)
                             pi.SetValue(t, value, null);
                     }
                 }
                 //对象添加到泛型集合中
                 ts.Add(t);
             }
             return ts;
         }
     }
 }

　　OK，这是引用类型的list转datatable，完毕。