C# 转换对象DataTable，DataGridView，List

public static List<T> ConvertDataTableToList<T>(DataTable dataTable) where T : new()
        {
            List<T> result = new List<T>();

            if (dataTable == null || dataTable.Rows.Count == 0)
            {
                return result;
            }

            foreach (DataRow row in dataTable.Rows)
            {
                T item = CreateItemFromRow<T>(row);
                result.Add(item);
            }

            return result;
        }

        private static T CreateItemFromRow<T>(DataRow row) where T : new()
        {
            T item = new T();
            PropertyInfo[] properties = typeof(T).GetProperties();

            foreach (PropertyInfo property in properties)
            {
                string columnName = property.Name;

                if (!row.Table.Columns.Contains(columnName))
                {
                    foreach (DataColumn column in row.Table.Columns)
                    {
                        if (string.Equals(column.ColumnName, columnName, StringComparison.OrdinalIgnoreCase))
                        {
                            columnName = column.ColumnName;
                            break;
                        }
                    }
                }

                if (row.Table.Columns.Contains(columnName))
                {
                    if (property.PropertyType == typeof(DateTime?))
                    {
                        DateTime? value = null;
                        string dateString = row[columnName].ToString();
                        DateTime parsedDate;

                        if (DateTime.TryParse(dateString, out parsedDate))
                        {
                            value = parsedDate;
                        }
                        property.SetValue(item, value);
                    }
                    else if (property.PropertyType == typeof(int?))
                    {
                        int? value = null;
                        string dateString = row[columnName].ToString();
                        int parsedDate;

                        if (int.TryParse(dateString, out parsedDate))
                        {
                            value = parsedDate;
                        }
                        property.SetValue(item, value);
                    }
                    else if (property.PropertyType == typeof(bool?))
                    {
                        bool? value = null;
                        string dateString = row[columnName].ToString();
                        bool parsedDate;

                        if (bool.TryParse(dateString, out parsedDate))
                        {
                            value = parsedDate;
                        }
                        property.SetValue(item, value);
                    }
                    else
                    {
                        object value = Convert.ChangeType(row[columnName], property.PropertyType);
                        property.SetValue(item, value);
                    }
                }
            }

            return item;
        }

public static DataTable ConvertListToDataTable(IList list)
        {
            DataTable result = new DataTable();
            if (list.Count > 0)
            {
                PropertyInfo[] propertys = list[0].GetType().GetProperties();
                foreach (PropertyInfo pi in propertys)
                {
                    //result.Columns.Add(pi.Name, pi.PropertyType);

                    Type colType = pi.PropertyType;
                    if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition() == typeof(Nullable<>)))
                    {
                        colType = colType.GetGenericArguments()[0];
                    }
                    result.Columns.Add(new DataColumn(pi.Name, colType));
                }
                for (int i = 0; i < list.Count; i++)
                {
                    ArrayList tempList = new ArrayList();
                    foreach (PropertyInfo pi in propertys)
                    {
                        object obj = pi.GetValue(list[i], null) == null ? DBNull.Value : pi.GetValue(list[i], null);
                        tempList.Add(obj);
                    }
                    object[] array = tempList.ToArray();
                    result.LoadDataRow(array, true);
                }
            }
            return result;
        }

public static DataTable ConvertDgvToTable(DataGridView dgv)
        {
            DataTable dt = new DataTable();
            for (int count = 0; count < dgv.Columns.Count; count++)
            {
                DataColumn dc = new DataColumn(dgv.Columns[count].Name.ToString());
                dt.Columns.Add(dc);
            }
            for (int row = 0; row < dgv.Rows.Count; row++)
            {
                DataRow dr = dt.NewRow();
                for (int countsub = 0; countsub < dgv.Columns.Count; countsub++)
                {
                    dr[countsub] = dgv.Rows[row].Cells[countsub].Value;
                }
                dt.Rows.Add(dr);
            }
            return dt;
        }