将LINQ查询的结果转化为DataTable

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

namespace COMMON
{
  public static class DataHelper
  {

    public static DataTable _data;
    public static DataTable Data
  {
    get { return _data; }
    set { _data = value; }
  }

public static DataTable GetData()
{
  DATA.ProTestDataContext dataContext=new ProTestDataContext();
  var dt = from fx in dataContext.TaskTab select fx;
  DataTable dtt=new DataTable();
  dtt = ConvertToDataTable(dt.ToList());
  Data = dtt;
  return Data;
}

#region "Convert Generic List to DataTable"
/// <summary>
/// Convert a List{T} to a DataTable.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="items"></param>
/// <returns></returns>
public static DataTable ConvertToDataTable<T>(this 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>
/// <param name="t"></param>
/// <returns></returns>
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>
/// <param name="t"></param>
/// <returns></returns>
public static Type GetCoreType(Type t)
{
  if (t != null && IsNullable(t))
  {
    if (!t.IsValueType)
    {
      return t;
    }
    else
    {
      return Nullable.GetUnderlyingType(t);
    }
  }
  else
  {
    return t;
  }
}
#endregion
  }
}

posted @ 2014-03-20 17:07  帅刺猬之家  阅读(388)  评论(0编辑  收藏  举报