在專案中常常常使用到DataTable,假設DataTable使用得當，不僅能使程式簡潔有用，並且可以提高效能，達到事半功倍的效果，現對DataTable的使用技巧進行一下總結。 

        一、DataTable簡單介紹    

          (1)建構函式 
          DataTable()   不帶引數初始化DataTable 類的新例項。 
          DataTable(string tableName)  用指定的表名初始化DataTable 類的新例項。 
          DataTable(string tableName, string tableNamespace) 用指定的表名和名稱空間初始化DataTable類的新例項。 
          (2) 常常使用屬性 
          CaseSensitive    指示表中的字串比較是否區分大寫和小寫。 
          ChildRelations   獲取此DataTable 的子關係的集合。 
          Columns             獲取屬於該表的列的集合。 
          Constraints        獲取由該表維護的約束的集合。 
          DataSet               獲取此表所屬的DataSet。DataSet相關資訊，可見我曾經的一篇文章《資料訪問(2)－DataSet》 
          DefaultView       獲取可能包含篩選檢視或遊標位置的表的自己定義檢視。 
          HasErrors          獲取一個值，該值指示該表所屬的DataSet 的不論什麼表的不論什麼行中是否有錯誤。 
          MinimumCapacity  獲取或設定該表最初的起始大小。該表中行的最初起始大小。預設值為 50。 
          Rows                  獲取屬於該表的行的集合。 
          TableName       獲取或設定DataTable 的名稱。 

          (3)常常使用解決方案 
          AcceptChanges()   提交自上次呼叫AcceptChanges() 以來對該表進行的全部更改。 
          BeginInit()         開始初始化在視窗上使用或由還有一個元件使用的DataTable。初始化發生在執行時。

          Clear()               清除全部資料的DataTable。 
          Clone()              克隆DataTable 的結構，包含全部DataTable 架構和約束。 
          EndInit()            結束在視窗上使用或由還有一個元件使用的DataTable 的初始化。初始化發生在執行時。 
          ImportRow(DataRow row)    將DataRow 拷貝到DataTable 中，保留不論什麼屬性設定以及初始值和當前值。 
          Merge(DataTable table)  將指定的DataTable 與當前的DataTable 合併。 
          NewRow()         建立與該表具有相同架構的新DataRow。
 
        二、DataTable使用技巧

      （1）Create a DataTable
         DataTable dt = new DataTable("Table_AX"); 

      （2）Add columns for DataTable
        //Method 1
        dt.Columns.Add("column0", System.Type.GetType("System.String"));
        //Method 2
        DataColumn dc = new DataColumn("column1", System.Type.GetType("System.Boolean"));
        dt.Columns.Add(dc); 

       （3）Add rows for DataTable
         //Initialize the row
         DataRow dr = dt.NewRow();
         dr["column0"] = "AX";
         dr["column1"] = true;
         dt.Rows.Add(dr);
         //Doesn't initialize the row
         DataRow dr1 = dt.NewRow();
         dt.Rows.Add(dr1);  

        （4）Select row
         //Search the second row 假設沒有賦值,則用is null來select
         DataRow[] drs = dt.Select("column1 is null");
         DataRow[] drss = dt.Select("column0 = 'AX'"); 

        （5）Copy DataTable include data
         DataTable dtNew = dt.Copy(); 

        （6）Copy DataTable only scheme
         DataTable dtOnlyScheme = dt.Clone(); 

        （7）Operate one row
         //對dt的操作
         //Method 1
         DataRow drOperate = dt.Rows[0];
         drOperate["column0"] = "AXzhz";
         drOperate["column1"] = false;
         //Method 2
         drOperate[0] = "AXzhz";
         drOperate[1] = false;
         //Method 3
         dt.Rows[0]["column0"] = "AXzhz";
         dt.Rows[0]["column1"] = false;
         //Method 4
         dt.Rows[0][0] = "AXzhz";
         dt.Rows[0][1] = false; 

       （8）Evaluate another DataTable's row to current Datatable
         dtOnlyScheme.Rows.Add(dt.Rows[0].ItemArray); 

       （9）Convert to string
         System.IO.StringWriter sw = new System.IO.StringWriter();
         System.Xml.XmlTextWriter xw = new System.Xml.XmlTextWriter(sw);
         dt.WriteXml(xw);
         string s = sw.ToString();

        （10）Filter DataTable
         dt.DefaultView.RowFilter = "column1 <> true";
         dt.DefaultView.RowFilter = "column1 = true";

        （11）Sort row
          dt.DefaultView.Sort = "ID ,Name ASC";
          dt=dt.DefaultView.ToTable();

         （12）Bind DataTable
           //繫結的事實上是DefaultView
          gvTestDataTable.DataSource = dt;
          gvTestDataTable.DataBind();

         （13）judge the DataTable’s Column name is a string
          //推斷一個字串是否為DataTable的列名
         dtInfo.Columns.Contains("AX");

         （14）DataTable convert to XML and XML convert to DataTable
          protected void Page_Load(object sender, EventArgs e)
          {
             DataTable dt_AX = new DataTable();
             //dt_AX.Columns.Add("Sex", typeof(System.Boolean));
             //DataRow dr = dt_AX.NewRow();
             //dr["Sex"] = true;
             //dt_AX.Rows.Add(dr);
             string xml=ConvertBetweenDataTableAndXML_AX(dt_AX);
             DataTable dt = ConvertBetweenDataTableAndXML_AX(xml);
         }
         public string ConvertBetweenDataTableAndXML_AX(DataTable dtNeedCoveret)
        {
             System.IO.TextWriter tw = new System.IO.StringWriter();
             //if TableName is empty, WriteXml() will throw Exception.                 

dtNeedCoveret.TableName=dtNeedCoveret.TableName.Length==0?"Table_AX":dtNeedCoveret.TableName;
             dtNeedCoveret.WriteXml(tw);
             dtNeedCoveret.WriteXmlSchema(tw);
             return tw.ToString();
        }
         public DataTable ConvertBetweenDataTableAndXML_AX(string xml)
        {
             System.IO.TextReader trDataTable = new System.IO.StringReader(xml.Substring(0, xml.IndexOf("<?xml")));
             System.IO.TextReader trSchema = new System.IO.StringReader(xml.Substring(xml.IndexOf("<?xml")));
             DataTable dtReturn = new DataTable();
             dtReturn.ReadXmlSchema(trSchema);
             dtReturn.ReadXml(trDataTable);
             return dtReturn;
        }