DataTable部分代码

// Create DataTable
        DataTable dt  =   new  DataTable();
        dt.CaseSensitive  =   true ;
         // Create DataColumns
        DataColumn col1  =   new  DataColumn( " id " ,  typeof ( int ));
        DataColumn col2  =   new  DataColumn( " UserName " ,  typeof ( string ));
         // Config Propertyies
        col2.AllowDBNull  =   false ;
        col2.MaxLength  =   50 ;
        col2.Unique  =   true ;
        

        col1.AutoIncrement  =   true ;
        col1.AutoIncrementSeed  =   100 ;
        col1.AutoIncrementStep  =   1 ;
        col1.ReadOnly  =   true ;
         // the DataColumn with Expression
        DataColumn col3  =   new  DataColumn( " Expression " ,  typeof ( string ));
        col3.Expression  =   " id+UserName " ;

         // add DataColumns to dt;
        dt.Columns.Add(col1);
        dt.Columns.Add(col2);
        dt.Columns.Add(col3);
        dt.PrimaryKey  =   new  DataColumn[]  { dt.Columns[0] } ;
         // Create test data
        DataRow dr  =  dt.NewRow();
        dr[ 1 ]  =   " Roboth " ;
        dt.Rows.Add(dr);
        dr  =  dt.NewRow();
        dr[ 1 ]  =   " xinsoft " ;
        dt.Rows.Add(dr);
        dr  =  dt.NewRow();
        dr[ 1 ]  =   " SpiderMan " ;
        dt.Rows.Add(dr);
         // bind to gridview
         this .gridview1.DataSource  =  dt;
         this .gridview1.DataBind();

         // example1 for edit
        DataRow dr1  =  dt.Rows.Find( 102 );
        
         if  (dr1  ==   null )
         {
            Response.Write("no find");
        }
         else
         {
           
            dr1.BeginEdit();
            dr1[1] = "SpiderWoman";
            dr1.EndEdit();
        }
         // example2 for edit
         object [] obj  =   new   object []  {null,"Spo",null } ;
        DataRow dr2  =  dt.Rows.Find( 102 );
         if  (dr2.IsNull( 2 )) // 赋值是 DBNull.Value
         {
            
            dr2[2] = "test";
        }
        dr2.ItemArray  =  obj;

         // example for delete
        DataRow dr_D  =  dt.Rows.Find( 102 );
        dr_D.Delete();
         // Remove corresponding row
        dt.Rows.Remove(dt.Rows.Find( 101 ));
         /**/ ////Remove corresponding row again
        dt.Rows.RemoveAt( 0 );
         this .gridview2.DataSource  =  dt;
         this .gridview2.DataBind();
        DataSet ds  =   new  DataSet();
        Response.Write(ds.DataSetName);