DataTable添加列和行的方法

方法一:

        DataTable  tblDatas = new DataTable("Datas");
        DataColumn dc = null;

        //赋值给 dc，是便于对每一个datacolumn的操作
        dc = tblDatas.Columns.Add("ID", Type.GetType("System.Int32"));
        dc.AutoIncrement = true;//自动增加
        dc.AutoIncrementSeed = 1;//起始为1
        dc.AutoIncrementStep = 1;//步长为1
        dc.AllowDBNull = false;//

        dc = tblDatas.Columns.Add("Product", Type.GetType("System.String"));
        dc = tblDatas.Columns.Add("Version", Type.GetType("System.String"));
        dc = tblDatas.Columns.Add("Description", Type.GetType("System.String"));

        DataRow newRow;
        newRow = tblDatas.NewRow();
        newRow["Product"] = "大话西游";
        newRow["Version"] = "2.0";
        newRow["Description"] = "我很喜欢";
        tblDatas.Rows.Add(newRow);

        newRow = tblDatas.NewRow();
        newRow["Product"] = "梦幻西游";
        newRow["Version"] = "3.0";
        newRow["Description"] = "比大话更幼稚";
        tblDatas.Rows.Add(newRow);

        方法二:

         DataTable tblDatas = new DataTable("Datas");
        tblDatas.Columns.Add("ID", Type.GetType("System.Int32"));
        tblDatas.Columns[0].AutoIncrement = true;
        tblDatas.Columns[0].AutoIncrementSeed = 1;
        tblDatas.Columns[0].AutoIncrementStep = 1;

        tblDatas.Columns.Add("Product", Type.GetType("System.String"));
        tblDatas.Columns.Add("Version", Type.GetType("System.String"));
        tblDatas.Columns.Add("Description", Type.GetType("System.String"));

        tblDatas.Rows.Add(new object[]{null,"a","b","c"});
        tblDatas.Rows.Add(new object[] { null, "a", "b", "c" });
        tblDatas.Rows.Add(new object[] { null, "a", "b", "c" });
        tblDatas.Rows.Add(new object[] { null, "a", "b", "c" });
        tblDatas.Rows.Add(new object[] { null, "a", "b", "c" });

        方法三：
        DataTable table = new DataTable ();

          //创建table的第一列
        DataColumn priceColumn = new DataColumn();
        //该列的数据类型
        priceColumn.DataType = System.Type.GetType("System.Decimal");
        //该列得名称
         priceColumn.ColumnName = "price";
         //该列得默认值
        priceColumn.DefaultValue = 50;

        // 创建table的第二列
        DataColumn taxColumn = new DataColumn();
        taxColumn.DataType = System.Type.GetType("System.Decimal");
         //列名
        taxColumn.ColumnName = "tax";
        //设置该列得表达式，用于计算列中的值或创建聚合列
        taxColumn.expression_r_r_r = "price * 0.0862";
        // Create third column.
        DataColumn totalColumn = new DataColumn();
        totalColumn.DataType = System.Type.GetType("System.Decimal");
        totalColumn.ColumnName = "total";
        //该列的表达式，值是得到的是第一列和第二列值得和
        totalColumn.expression_r_r_r = "price + tax";

        // 将所有的列添加到table上
        table.Columns.Add(priceColumn);
        table.Columns.Add(taxColumn);
        table.Columns.Add(totalColumn);

        //创建一行
         DataRow row = table.NewRow();
         //将此行添加到table中
        table.Rows.Add(row);

        //将table放在试图中
         DataView view = new DataView(table);
        dg.DataSource = view;

        dg.DataBind();