C#中Datatable和List互相转换
其实早就该写的，哈哈，不过今天刚想起来注册，热热手，就写一下，哈哈。
直接上内容吧：
建立一个控制台应用程序，
1 List<students> Studentlist = 2 new List<students>{ 3 new students{ Name = "zhagnsan1", Chinese = 101, Math = 90, English = 80 }, 4 new students{ Name = "zhagnsan2", Chinese = 102, Math = 90, English = 80 }, 5 new students{ Name = "zhagnsan3", Chinese = 103, Math = 90, English = 80 } 6 }; 7 DataTable dt = ListToDatatableHelper.ToDataTable(Studentlist); 8 this.dataGridView1.DataSource = dt; 9 10 List<students> list = DatatableToListHelper.ConvertToList(dt); 11 12 public class students 13 { 14 public string Name { get; set; } 15 public double English { get; set; } 16 public double Chinese { get; set; } 17 public double Math { get; set; } 18 }
ListToDatatableHelper.cs中的内容为：
1 using System; 2 using System.Collections.Generic; 3 using System.Data; 4 using System.Linq; 5 using System.Reflection; 6 using System.Text; 7 using System.Threading.Tasks; 8 9 namespace ListToDatatable 10 { 11 public class ListToDatatableHelper 12 { 13 /// <summary> 14 /// Convert a List{T} to a DataTable. 15 /// </summary> 16 public static DataTable ToDataTable<T>(List<T> items) 17 { 18 var tb = new DataTable(typeof(T).Name); 19 20 PropertyInfo[] props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance); 21 22 foreach (PropertyInfo prop in props) 23 { 24 Type t = GetCoreType(prop.PropertyType); 25 tb.Columns.Add(prop.Name, t); 26 } 27 28 foreach (T item in items) 29 { 30 var values = new object[props.Length]; 31 32 for (int i = 0; i < props.Length; i++) 33 { 34 values[i] = props[i].GetValue(item, null); 35 } 36 37 tb.Rows.Add(values); 38 } 39 40 return tb; 41 } 42 43 /// <summary> 44 /// Determine of specified type is nullable 45 /// </summary> 46 public static bool IsNullable(Type t) 47 { 48 return !t.IsValueType || (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable<>)); 49 } 50 51 /// <summary> 52 /// Return underlying type if type is Nullable otherwise return the type 53 /// </summary> 54 public static Type GetCoreType(Type t) 55 { 56 if (t != null && IsNullable(t)) 57 { 58 if (!t.IsValueType) 59 { 60 return t; 61 } 62 else 63 { 64 return Nullable.GetUnderlyingType(t); 65 } 66 } 67 else 68 { 69 return t; 70 } 71 } 72 73 //************************************************* 74 /// <summary> 75 /// List转Datatable 76 /// </summary> 77 /// <typeparam name="T"></typeparam> 78 /// <param name="table"></param> 79 /// <returns></returns> 80 public static IList<T> ConvertTo<T>(DataTable table) 81 { 82 if (table == null) 83 { 84 return null; 85 } 86 87 List<DataRow> rows = new List<DataRow>(); 88 89 foreach (DataRow row in table.Rows) 90 { 91 rows.Add(row); 92 } 93 94 return ConvertTo<T>(rows); 95 } 96 97 public static IList<T> ConvertTo<T>(IList<DataRow> rows) 98 { 99 IList<T> list = null; 100 101 if (rows != null) 102 { 103 list = new List<T>(); 104 105 foreach (DataRow row in rows) 106 { 107 T item = CreateItem<T>(row); 108 list.Add(item); 109 } 110 } 111 112 return list; 113 } 114 115 public static T CreateItem<T>(DataRow row) 116 { 117 T obj = default(T); 118 if (row != null) 119 { 120 obj = Activator.CreateInstance<T>(); 121 122 foreach (DataColumn column in row.Table.Columns) 123 { 124 PropertyInfo prop = obj.GetType().GetProperty(column.ColumnName); 125 try 126 { 127 object value = row[column.ColumnName]; 128 prop.SetValue(obj, value, null); 129 } 130 catch 131 { //You can log something here 132 //throw; 133 } 134 } 135 } 136 137 return obj; 138 } 139 } 140 }
DatatableToListHelper.cs中的内容为：
1 using NPOI.SS.Formula.Functions; 2 using System; 3 using System.Collections.Generic; 4 using System.Data; 5 using System.Linq; 6 using System.Reflection; 7 using System.Text; 8 using System.Threading.Tasks; 9 using static ListToDatatable.Form1; 10 11 namespace ListToDatatable 12 { 13 class DatatableToListHelper 14 { 15 /// <summary> 16 /// 利用反射和泛型 17 /// </summary> 18 /// <param name="dt"></param> 19 /// <returns></returns> 20 public static List<students> ConvertToList(DataTable dt) 21 { 22 // 定义集合 23 List<students> ts = new List<students>(); 24 25 // 获得此模型的类型 26 Type type = typeof(students); 27 //定义一个临时变量 28 string tempName = string.Empty; 29 //遍历DataTable中所有的数据行 30 foreach (DataRow dr in dt.Rows) 31 { 32 students t = new students(); 33 // 获得此模型的公共属性 34 PropertyInfo[] propertys = t.GetType().GetProperties(); 35 //遍历该对象的所有属性 36 foreach (PropertyInfo pi in propertys) 37 { 38 tempName = pi.Name;//将属性名称赋值给临时变量 39 //检查DataTable是否包含此列（列名==对象的属性名） 40 if (dt.Columns.Contains(tempName)) 41 { 42 // 判断此属性是否有Setter 43 if (!pi.CanWrite) continue;//该属性不可写，直接跳出 44 //取值 45 object value = dr[tempName]; 46 //如果非空，则赋给对象的属性 47 if (value != DBNull.Value) 48 pi.SetValue(t, value, null); 49 } 50 } 51 //对象添加到泛型集合中 52 ts.Add(t); 53 } 54 return ts; 55 } 56 } 57 }
OK，这是引用类型的list转datatable，完毕。
