C# DataTable 和List之间相互转换的方法

一、DataTable转换到List

方法1.

/// <summary>    
    /// 实体转换辅助类    
    /// </summary>    
    public class ModelConvertHelper
    {
        /// <summary>
        /// DataTable转换到List
        /// </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;
        }


       
    } 

方法2.

 public class ModelConvertHelper<T> where   T : new()    
     {    
        public static IList<T> ConvertToModel(DataTable dt)    
         {    
            // 定义集合    
             IList<T> ts = new List<T>(); 
     
            // 获得此模型的类型   
             Type type = typeof(T);      
            string tempName = "";      
      
            foreach (DataRow dr in dt.Rows)      
             {    
                 T t = new T();     
                // 获得此模型的公共属性      
                 PropertyInfo[] propertys = t.GetType().GetProperties(); 
                foreach (PropertyInfo pi in propertys)      
                 {      
                     tempName = pi.Name;  // 检查DataTable是否包含此列    
   
                    if (dt.Columns.Contains(tempName))      
                     {      
                        // 判断此属性是否有Setter      
                        if (!pi.CanWrite) continue;         
   
                        object value = dr[tempName];      
                        if (value != DBNull.Value)      
                             pi.SetValue(t, value, null);  
                     }     
                 }      
                 ts.Add(t);      
             }     
            return ts;     
         }     
     }    

使用方式：  

// 获得查询结果  
DataTable dt = DbHelper.ExecuteDataTable(...);  
// 把DataTable转换为IList<UserInfo>  
IList<UserInfo> users = ModelConvertHelper<UserInfo>.ConvertToModel(dt);

二、List<T>/IEnumerable转换到DataTable/DataView

方法一

/// <summary>
/// Convert a List{T} to a DataTable.
/// </summary>
private 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 = 0; 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;
    }
}

方法二

public static DataTable ToDataTable<T>(IEnumerable<T> collection)
 {
     var props = typeof(T).GetProperties();
     var dt = new DataTable();
     dt.Columns.AddRange(props.Select(p => new DataColumn(p.Name, p.PropertyType)).ToArray());
     if (collection.Count() > 0)
     {
         for (int i = 0; i < collection.Count(); i++)
         {
             ArrayList tempList = new ArrayList();
             foreach (PropertyInfo pi in props)
             {
                 object obj = pi.GetValue(collection.ElementAt(i), null);
                 tempList.Add(obj);
             }
             object[] array = tempList.ToArray();
             dt.LoadDataRow(array, true);
         }
     }
     return dt;
 }

 转载自http://www.okbase.net/doc/details/3282