之前写了个  List<T> item.toDataTable() 这种链式调用的List<T>转换为DataTable的方法，有两位热心的网友提出了存在的一些缺陷，如果传入的obj参数不是List而是单个object对象或传入的是单类型的List时转换会出错，现对代码进行了些修改，反正代码测试基本是跑通了，对List<T>，单个Object对象，以及List<string>、List<int>这类传入的数据都能转，但还是感觉整个判断过程可能不够严谨，希望高手指正。

之前的代码：C# List<T> 转 DataTable

public static DataTable toDataTable(this object obj,string _tName = null)
        {
            Type t = obj.GetType(); 
            dynamic ts = obj;

            DataTable DT = new DataTable();
            PropertyInfo[] pi;

            //判断obj是否为单个的实体类
            if (t.Name.IndexOf("List") < 0)
            {
                pi = ts.GetType().GetProperties(BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Public);
                DT.TableName = _tName == null ? ts.GetType().ToString() : _tName;
                foreach (PropertyInfo p in pi)
                {
                    DT.Columns.Add(p.Name, p.PropertyType);
                }
                DataRow dr1 = DT.NewRow();
                foreach (PropertyInfo p in pi)
                {
                    dr1[p.Name] = p.GetValue(ts, null);
                }
                DT.Rows.Add(dr1);
                return DT;
            }

            //判断obj是否为单类型对象
            if (t.ToString().IndexOf("System.String")>=0 || t.ToString().IndexOf("System.Object")>=0 
                || t.ToString().IndexOf("System.Int")>=0 || t.ToString().IndexOf("System.Boolean")>=0)
            {
                DT.TableName = _tName == null ? "Table1" : _tName;
                DT.Columns.Add("Column1", typeof(object));
                foreach (var v in ts)
                {
                    DataRow dr2 = DT.NewRow();
                    dr2["Column1"] = v ;
                    DT.Rows.Add(dr2);
                }
                return DT;
            }

            pi = ts[0].GetType().GetProperties(BindingFlags.IgnoreCase | BindingFlags.Instance | BindingFlags.Public);            
            DT.TableName = _tName == null ? ts[0].GetType().ToString() : _tName;
            foreach (PropertyInfo p in pi)
            {
                DT.Columns.Add(p.Name, p.PropertyType);
            }

            DataRow dr = null;
            foreach (var v in ts)
            {
                dr = DT.NewRow();
                foreach (PropertyInfo p in pi)
                {
                    dr[p.Name] = p.GetValue(v, null);
                }
                DT.Rows.Add(dr);
            }

            return DT;
        }

测试代码：

private static void ReadDataTableFromList()
        {
            ConnConfig conn = new ConnConfig(dbtype: DBType.SQLServer, connstring: SQLConnStr);
            DBHelper<VMIS_model> vioDB = new DBHelper<VMIS_model>(conn);

            List<VMIS_model> list = vioDB.Select(whereSQL: "PlateNumber=@PN", sqlParams: new ORMParameter[]
            {
                new ORMParameter("@PN","车牌ABCDE")
            });

            Console.WriteLine("List<T>.toDataTable()  测试：");
            DataTable DT = list.toDataTable("List_VMIS");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("单个object.toDataTable() 测试：");
            VMIS_model vi = list.First();
            DT = vi.toDataTable("VMIS");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("List<string>.toDataTable()  测试：");
            List<string> list1 = new List<string>();
            list1.Add("张三");
            list1.Add("李四");
            list1.Add("王五");
            DT = list1.toDataTable("List_String");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("List<int>.toDataTable()  测试：");
            List<int> list2 = new List<int>();
            list2.Add(-2021);
            list2.Add(2022);
            list2.Add(2023);
            DT = list2.toDataTable("List_Int");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("List<long>.toDataTable()  测试：");
            List<long> list3 = new List<long>();
            list3.Add(3232235876000);
            list3.Add(3232235877000);
            list3.Add(-3232235878000);
            DT = list3.toDataTable();
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("List<bool>.toDataTable()  测试：");
            List<bool> list4 = new List<bool>();
            list4.Add(true);
            list4.Add(false);
            DT = list4.toDataTable("List_Bool");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

            Console.WriteLine("List<object>.toDataTable()  测试：");
            List<object> list5 = new List<object>();
            list5.Add("张三");
            list5.Add(2022);
            list5.Add(-2023);
            list5.Add(3232235877000);
            list5.Add(-3232235878000);
            list5.Add(true); 
            list5.Add(false);  
            DT = list5.toDataTable("List_Object");
            Console.WriteLine("数据加载到DataTable 【" + DT.TableName + "】 完成，共载入数据：" + DT.Rows.Count.ToString());
            Console.WriteLine(JsonConvert.SerializeObject(DT, Formatting.Indented));
            Console.WriteLine("----------------------------------------------------------------------");

        }