C# List<T> 转 DataTable 方法修改版

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所属分类:.NET技术
摘要

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:

C# List<T> 转 DataTable 方法修改版C# List<T> 转 DataTable 方法修改版

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("----------------------------------------------------------------------");          }

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结果:

C# List<T> 转 DataTable 方法修改版C# List<T> 转 DataTable 方法修改版

List<T> to DataTable 转换测试:  --------------------------------------------- List<T>.toDataTable()  测试: 数据加载到DataTable 【List_VMIS】 完成,共载入数据:3 [   {     "ID": "2105082103590123269484848995",     "PlateNumber": "车牌ABCDE",     "V_Text": "超速,超过限速110.00%",     "V_Address": "超速卡口:xxxxx",     "V_date": "2021-05-08T21:03:43",     "CarOwner": ""   },   {     "ID": "2105082103590435798531004957",     "PlateNumber": "车牌ABCDE",     "V_Text": "超速,超过限速113.33%",     "V_Address": "超速卡口:xxxxx",     "V_date": "2021-05-08T21:03:13",     "CarOwner": ""   },   {     "ID": "2105082147592512464100535248",     "PlateNumber": "车牌ABCDE",     "V_Text": "超速,超过限速83.33%",     "V_Address": "超速卡口:xxxxx",     "V_date": "2021-05-08T21:47:50",     "CarOwner": ""   } ] ---------------------------------------------------------------------- 单个object.toDataTable() 测试: 数据加载到DataTable 【VMIS】 完成,共载入数据:1 [   {     "ID": "2105082103590123269484848995",     "PlateNumber": "车牌ABCDE",     "V_Text": "超速,超过限速110.00%",     "V_Address": "超速卡口:xxxxx",     "V_date": "2021-05-08T21:03:43",     "CarOwner": ""   } ] ---------------------------------------------------------------------- List<string>.toDataTable()  测试: 数据加载到DataTable 【List_String】 完成,共载入数据:3 [   {     "Column1": "张三"   },   {     "Column1": "李四"   },   {     "Column1": "王五"   } ] ---------------------------------------------------------------------- List<int>.toDataTable()  测试: 数据加载到DataTable 【List_Int】 完成,共载入数据:3 [   {     "Column1": -2021   },   {     "Column1": 2022   },   {     "Column1": 2023   } ] ---------------------------------------------------------------------- List<long>.toDataTable()  测试: 数据加载到DataTable 【Table1】 完成,共载入数据:3 [   {     "Column1": 3232235876000   },   {     "Column1": 3232235877000   },   {     "Column1": -3232235878000   } ] ---------------------------------------------------------------------- List<bool>.toDataTable()  测试: 数据加载到DataTable 【List_Bool】 完成,共载入数据:2 [   {     "Column1": true   },   {     "Column1": false   } ] ---------------------------------------------------------------------- List<object>.toDataTable()  测试: 数据加载到DataTable 【List_Object】 完成,共载入数据:7 [   {     "Column1": "张三"   },   {     "Column1": 2022   },   {     "Column1": -2023   },   {     "Column1": 3232235877000   },   {     "Column1": -3232235878000   },   {     "Column1": true   },   {     "Column1": false   } ] ----------------------------------------------------------------------

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C# List<T> 转 DataTable - 小政哥01 - 博客园 (cnblogs.com)