1 using System;
2 using System.Data;
3 using System.Collections;
4 using System.Collections.Generic;
5 using System.Configuration;
6 using System.Reflection;
7 using System.Linq;
8 using System.Xml.Linq;
9
10 namespace UserFunction
11 {
12 /// <summary>
13 /// Summary description for LinqToDataTable
14 /// </summary>
15 static public class LinqToDataTable
16 {
17 static public DataTable ToDataTable<T>(this IEnumerable<T> varlist, CreateRowDelegate<T> fn)
18 {
19
20 DataTable dtReturn = new DataTable();
21
22 // column names
23
24 PropertyInfo[] oProps = null;
25
26 // Could add a check to verify that there is an element 0
27
28 foreach (T rec in varlist)
29 {
30
31 // Use reflection to get property names, to create table, Only first time, others will follow
32
33 if (oProps == null)
34 {
35
36 oProps = ((Type)rec.GetType()).GetProperties();
37
38 foreach (PropertyInfo pi in oProps)
39 {
40 // 当字段类型是Nullable<>时
41 Type colType = pi.PropertyType; if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
42 {
43
44 colType = colType.GetGenericArguments()[0];
45
46 }
47
48 dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
49
50 }
51
52 }
53
54 DataRow dr = dtReturn.NewRow(); foreach (PropertyInfo pi in oProps)
55 {
56
57 dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue(rec, null);
58
59 }
60
61 dtReturn.Rows.Add(dr);
62
63 }
64
65 return (dtReturn);
66
67 }
68
69 public delegate object[] CreateRowDelegate<T>(T t);
70 }
71 }
72
73 /*
74 * 示例:
75 * var query = from ....;
76 * DataTable dt = query.ToDataTable(rec => new object[] { query });
77 *
78 */
