喂LINQ结果到一个数据行 [英] Feed a LINQ result into a DataROW

问题描述

本作品：

var Result = from e in actual.Elements
                         select new
                         {
                             Key = e.Key,
                             ValueNumber = e.Value.ValueNumber,
                             ValueString = e.Value.ValueString,
                             ValueBinary = e.Value.ValueBinary,
                             ValueDateTime = e.Value.ValueDateTime
                         };

但是，这并不工作：​​

But this doesn't work:

IEnumerable<DataRow> Result = from e in actual.Elements
                select new DataRow
                {
                    Key = e.Key,
                    ValueNumber = e.Value.ValueNumber,
                    ValueString = e.Value.ValueString,
                    ValueBinary = e.Value.ValueBinary,
                    ValueDateTime = e.Value.ValueDateTime
                };

DataTable dt = Result.CopyToDataTable(Result);

你能不能帮我？我想代码的第二位的工作，这样我可以把它放到数据表。我认识的语法是＃2完全错误的。你如何使用LINQ像这样指定列？

Can you fix it for me? I want the second bit of code to work so that I can put it into the DataTable. I realize the syntax is totally wrong in #2. How do you specify a column using LINQ like this?

推荐答案

您可以编写采取任何<$ C $一个简单的扩展方法C>的IEnumerable< T> ，使用反射来获取的PropertyDescriptor 取值和T有关，并创建一个的DataColumn 每个

You can write a simple extension method that takes any IEnumerable<T>, uses reflection to get the PropertyDescriptors associated with T, and creates a DataColumn for each

public static DataTable PropertiesToDataTable(this IEnumerable<T> source)
{
      DataTable dt = new DataTable();

      var props = TypeDescriptor.GetProperties(typeof(T));

      foreach (PropertyDescriptor prop in props)
      {
          DataColumn dc = dt.Columns.Add(prop.Name,prop.PropertyType);
          dc.Caption = prop.DisplayName;
          dc.ReadOnly = prop.IsReadOnly;
      }

      foreach (T item in source)
      {
            DataRow dr = dt.Rows.NewRow();
            foreach (PropertyDescriptor prop in props)
                dr[prop.Name] = prop.GetValue(item);

            dt.Rows.Add(dr);
      }

      return dt;     
}

这篇关于喂LINQ结果到一个数据行的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！