• csharp:Conversion Between DataTable and List


    /// <summary>
        /// http://www.codeproject.com/Tips/784090/Conversion-Between-DataTable-and-List-in-Csharp 
        /// </summary>
        public static class ExtensionUtility
        {
        
            /// <summary>
            /// Converts List To DataTable
            /// </summary>
            /// <typeparam name="TSource"></typeparam>
            /// <param name="data"></param>
            /// <returns></returns>
            public static DataTable ToDataTable<TSource>(this IList<TSource> data)
            {
                DataTable dataTable = new DataTable(typeof(TSource).Name);
                PropertyInfo[] props = typeof(TSource).GetProperties(BindingFlags.Public | BindingFlags.Instance);
                foreach (PropertyInfo prop in props)
                {
                    dataTable.Columns.Add(prop.Name, Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType);
                }
    
                foreach (TSource item in data)
                {
                    var values = new object[props.Length];
                    for (int i = 0; i < props.Length; i++)
                    {
                        values[i] = props[i].GetValue(item, null);
                    }
                    dataTable.Rows.Add(values);
                }
                return dataTable;
            }
    
          
            /// <summary>
            /// Converts DataTable To List
            /// </summary>
            /// <typeparam name="TSource"></typeparam>
            /// <param name="dataTable"></param>
            /// <returns></returns>
            public static List<TSource> ToList<TSource>(this DataTable dataTable) where TSource : new()
            {
                var dataList = new List<TSource>();
    
                const BindingFlags flags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic;
                var objFieldNames = (from PropertyInfo aProp in typeof(TSource).GetProperties(flags)
                                     select new { Name = aProp.Name, Type = Nullable.GetUnderlyingType(aProp.PropertyType) ?? aProp.PropertyType }).ToList();
                var dataTblFieldNames = (from DataColumn aHeader in dataTable.Columns
                                         select new { Name = aHeader.ColumnName, Type = aHeader.DataType }).ToList();
                var commonFields = objFieldNames.Intersect(dataTblFieldNames).ToList();
    
                foreach (DataRow dataRow in dataTable.AsEnumerable().ToList())
                {
                    var aTSource = new TSource();
                    foreach (var aField in commonFields)
                    {
                        PropertyInfo propertyInfos = aTSource.GetType().GetProperty(aField.Name);
                        var value = (dataRow[aField.Name] == DBNull.Value) ? null : dataRow[aField.Name]; //if database field is nullable
                        propertyInfos.SetValue(aTSource, value, null);
                    }
                    dataList.Add(aTSource);
                }
                return dataList;
            }
        }
    

      测试数据源:

    public class Student
        {
            public long Id { get; set; }
            public string Name { get; set; }
            public short Age { get; set; }
            public DateTime DateOfCreation { get; set; }
            public bool? IsActive { get; set; }
        }
    
        public class Teacher
        {
            public long Id { get; set; }
            public string Name { get; set; }
            public Nullable<int> DepartmentId { get; set; }
        }
    
        public class Data
        {
            public static List<Student> GetStudents()
            {
                var list = new List<Student>
                {
                    new Student {Id = 1, Name = "Smith", Age = 18, DateOfCreation = DateTime.Now, IsActive = true},
                    new Student {Id = 2, Name = "Hook", Age = 16, DateOfCreation = DateTime.Now.AddDays(-1), IsActive = true},
                    new Student {Id = 3, Name = "Jhon", Age = 15, DateOfCreation = DateTime.Now.AddDays(-2), IsActive = true},
                    new Student {Id = 4, Name = "Alan", Age = 21, DateOfCreation = DateTime.Now.AddDays(-3), IsActive = true}
                };
                return list;
            }
    
            public static List<Teacher> GetTeachers()
            {
                var list = new List<Teacher>
                {
                    new Teacher {Id = 1, Name = "Smith", DepartmentId = 18 },
                    new Teacher {Id = 2, Name = "Hook", DepartmentId = 16 },
                    new Teacher {Id = 3, Name = "Jhon", DepartmentId = 15 },
                    new Teacher {Id = 4, Name = "Alan", DepartmentId = 21 }
                };
                return list;
            }
    
            public static DataTable DbNullInt()
            {
                DataTable table = new DataTable();
                table.Columns.Add("Id", typeof(long));
                table.Columns.Add("Name", typeof(string));
    
                DataColumn column;
                column = new DataColumn("DepartmentId", System.Type.GetType("System.Int32"));
                column.AllowDBNull = true;
                table.Columns.Add(column);
    
                table.Rows.Add(1, "Smith", DBNull.Value);
                table.Rows.Add(2, "Hook", 1);
    
    
                return table;
            }
        }
    

      测试:

                List<Student> students = Data.GetStudents();
                /*List to DataTable conversion*/
                DataTable studentTbl = students.ToDataTable();
                /*DataTable to List conversion*/
                List<Student> newStudents = studentTbl.ToList<Student>();//ExtensionUtility.ToList<Student>(newStudents);
                this.dataGridView1.DataSource = newStudents;
    
                /*List to DataTable conversion*/
                DataTable teacherTbl = Data.DbNullInt();
                /*DataTable to List conversion*/
                List<Teacher> newTeachers = teacherTbl.ToList<Teacher>();
    
               
                this.dataGridView2.DataSource = newTeachers;
    

      

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  • 原文地址:https://www.cnblogs.com/geovindu/p/4583480.html
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