LINQ查询结果转换为数据表C＃ [英] convert linq query results to datatable C#

问题描述

我要转换的LINQ查询结果以数据表，这样我可以分配到数据表GridView控件来显示它的ASP页面上。

I want to convert the linq query results to datatable so that I can assign datatable to GridView to show it on asp page.

但是我不能够将结果转换为数据表，我没有得到CopyToTable（）方法，在我的code。

However I am not able to convert the results to datatable, I am not getting CopyToTable() method in my code.

请指教一下我做错了吗？

please advise what am I doing wrong here?

 var gradeData = (from data in oAngieCtxt.prc_ShopInstanceCustomersData(Convert.ToInt32(this.ShopInstanceID), 10000, false)
                     .Where( row => row.RecievedPoints != "n/a" )
                    .GroupBy(row => new { row.Name })
                    .Select(g => new GroupedPoints()
                    {
                        Name = g.Key.Name,
                        TotalPoints = g.Sum(x => Convert.ToDouble(x.RecievedPoints) * (x.Weightage.ToString() == "0.00" ? 1 : Convert.ToDouble(x.Weightage)))
                    })
                     select data).ToList();

 DataTable dt = gradeData --gradeData.CopyToTable()

注：参考dataextentions DLL可用

Note: reference to dataextentions dll is available.

在此先感谢

推荐答案

您应该得到的 DataTableExtensions.CopyToDataTable

删除了ToList（）。

CopyToDataTable是的IEnumerable＆LT; D​​ataRow的方式＆gt; 扩展（不幸）

CopyToDataTable is an IEnumerable<DataRow> extension (unfortunately).

有与下面的自定义CopyToDataTable扩展方法解决方案。

There is a solution with custom CopyToDataTable extension method below.

var gradeData = (from data in oAngieCtxt.prc_ShopInstanceCustomersData(
                 Convert.ToInt32(this.ShopInstanceID), 10000, false)
                .Where( row => row.RecievedPoints != "n/a" )
                .GroupBy(row => new { row.Name })
                .Select(g => new
                {
                    Name = g.Key.Name,
                    TotalPoints = g.Sum(x => Convert.ToDouble(x.RecievedPoints) 
                    * (x.Weightage.ToString() == "0.00" ? 1 
                      : Convert.ToDouble(x.Weightage)))
                })
                 select data);

var dt = gradeData.CopyToDataTable();

编辑：

下面是 CopyToDataTable更有效的实现没有类型约束的DataRow。

Here is a more useful implementation of CopyToDataTable There is no type constraint to DataRow.

  public static class DataSetLinqOperators
  {
    public static DataTable CopyToDataTable<T>(this IEnumerable<T> source)
    {
        //you find the ObjectShredder implementation on the blog wich was linked.
        return new ObjectShredder<T>().Shred(source, null, null);
    }

    public static DataTable CopyToDataTable<T>(this IEnumerable<T> source, 
                                     DataTable table, LoadOption? options)
    {
        return new ObjectShredder<T>().Shred(source, table, options);
    }

  }

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