Example Analysis of asp.net DataTable-related Operation

这期内容当中小编将会给大家带来有关asp.net DataTable相关操作的示例分析，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。

#region DataTable筛选，排序返回符合条件行组成的新DataTable或直接用DefaultView按条件返回/// /// DataTable筛选，排序返回符合条件行组成的新DataTable或直接用DefaultView按条件返回/// eg:SortExprDataTable(dt,"Sex='男'","Time Desc",1)/// /// 传入的DataTable/// 筛选条件/// 排序条件/// 1,直接用DefaultView按条件返回,效率较高;2,DataTable筛选，排序返回符合条件行组成的新DataTablepublic static DataTable SortDataTable(DataTable dt, string strExpr, string strSort, int mode){ switch (mode) { case 1: //方法一 直接用DefaultView按条件返回 dt.DefaultView.RowFilter = strExpr; dt.DefaultView.Sort = strSort; return dt; case 2: //方法二 DataTable筛选，排序返回符合条件行组成的新DataTable DataTable dt1 = new DataTable(); DataRow[] GetRows = dt.Select(strExpr, strSort); //复制DataTable dt结构不包含数据 dt1 = dt.Clone(); foreach (DataRow row in GetRows) { dt1.Rows.Add(row.ItemArray); } return dt1; default: return dt; }}#endregion#region 获取DataTable前几条数据/// /// 获取DataTable前几条数据/// /// 前N条数据/// 源DataTable/// public static DataTable DtSelectTop(int TopItem, DataTable oDT){ if (oDT.Rows.Count < TopItem) return oDT; DataTable NewTable = oDT.Clone(); DataRow[] rows = oDT.Select("1=1"); for (int i = 0; i < TopItem; i++) { NewTable.ImportRow((DataRow)rows[i]); } return NewTable;}#endregion#region 获取DataTable中指定列的数据/// /// 获取DataTable中指定列的数据/// /// 数据源/// 新的DataTable的名词/// 指定的列名集合/// 返回新的DataTablepublic static DataTable GetTableColumn(DataTable dt, string tableName, params string[] strColumns){ DataTable dtn = new DataTable(); if (dt == null) { throw new ArgumentNullException("参数dt不能为null"); } try { dtn = dt.DefaultView.ToTable(tableName, true, strColumns); } catch (Exception e) { throw new Exception(e.Message); } return dtn;}#endregionusing System;using System.Collections.Generic;using System.Linq;using System.Data;using System.Collections;using System.Text;namespace GuanEasy{ /// /// DataSet助手 /// public class DataSetHelper { private class FieldInfo { public string RelationName; public string FieldName; public string FieldAlias; public string Aggregate; } private DataSet ds; private ArrayList m_FieldInfo; private string m_FieldList; private ArrayList GroupByFieldInfo; private string GroupByFieldList; public DataSet DataSet { get { return ds; } } #region Construction public DataSetHelper() { ds = null; } public DataSetHelper(ref DataSet dataSet) { ds = dataSet; } #endregion #region Private Methods private bool ColumnEqual(object objectA, object objectB) { if ( objectA == DBNull.Value && objectB == DBNull.Value ) { return true; } if ( objectA == DBNull.Value || objectB == DBNull.Value ) { return false; } return ( objectA.Equals( objectB ) ); } private bool RowEqual(DataRow rowA, DataRow rowB, DataColumnCollection columns) { bool result = true; for ( int i = 0; i < columns.Count; i++ ) { result &= ColumnEqual( rowA[ columns[ i ].ColumnName ], rowB[ columns[ i ].ColumnName ] ); } return result; } private void ParseFieldList(string fieldList, bool allowRelation) { if ( m_FieldList == fieldList ) { return; } m_FieldInfo = new ArrayList(); m_FieldList = fieldList; FieldInfo Field; string[] FieldParts; string[] Fields = fieldList.Split( ',' ); for ( int i = 0; i