DataTable转换成List<T>

 1  public static class DataTableToModel
 2     {
 3         public static List<T> ConvertToModel<T>(this DataTable dt)
 4         {
 5             if (dt == null || dt.Rows.Count == 0)
 6             {
 7                 return null;
 8             }
 9 
10             var result = new List<T>();
11 
12             var objType = typeof(T);
13             var properties = objType.GetProperties();
14             var columnNames = GetDataTableColumnNames(dt);
15 
16             foreach (DataRow dr in dt.Rows)
17             {
18                 var obj = objType.Assembly.CreateInstance(objType.FullName);
19                 //var obj = Activator.CreateInstance(objType);
20                 foreach (var property in properties)
21                 {
22                     if (columnNames.Contains(property.Name))
23                     { 
24                         var cellValue=dr[property.Name];
25                         object propertyValue=cellValue;
26 
27                         //非泛型
28                         if (!property.PropertyType.IsGenericType)
29                         {
30                             propertyValue = cellValue == null ? null : Convert.ChangeType(cellValue, property.PropertyType);
31                         }
32                         else //泛型Nullable<>
33                         {
34                             Type genericTypeDefinition = property.PropertyType.GetGenericTypeDefinition();
35                             if (genericTypeDefinition == typeof(Nullable<>))
36                             {
37                                 propertyValue = cellValue == null ? null : Convert.ChangeType(cellValue, Nullable.GetUnderlyingType(property.PropertyType));
38                             }
39                         }
40 
41                         property.SetValue(obj, propertyValue, null);
42                     }
43                 }
44 
45                 result.Add((T)obj);
46             }
47 
48             return result;
49         }
50 
51         private static HashSet<string> GetDataTableColumnNames(DataTable dt)
52         {
53             var columnNames = new HashSet<string>();
54             foreach (DataColumn column in dt.Columns)
55             {
56                 columnNames.Add(column.ColumnName);
57             }
58             return columnNames;
59         }
60     }