C#建立DataTable（轉載）

來源：https://www.cnblogs.com/xietianjiao/p/11213121.html
方法一:

DataTable tblDatas = new DataTable("Datas");
DataColumn dc = null;
dc = tblDatas.Columns.Add("ID", Type.GetType("System.Int32"));
dc.AutoIncrement = true;//自動增長
dc.AutoIncrementSeed = 1;//起始爲1
dc.AutoIncrementStep = 1;//步長爲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"] = "大話西遊";
newRow["Version"] = "2.0";
newRow["Description"] = "我很喜歡";
tblDatas.Rows.Add(newRow);

newRow = tblDatas.NewRow();
newRow["Product"] = "夢幻西遊";
newRow["Version"] = "3.0";
newRow["Description"] = "比大話更幼稚";
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 ();

//建立table的第一列
DataColumn priceColumn = new DataColumn();
//該列的數據類型
priceColumn.DataType = System.Type.GetType("System.Decimal");
//該列得名稱
priceColumn.ColumnName = "price";
//該列得默認值
priceColumn.DefaultValue = 50;

// 建立table的第二列
DataColumn taxColumn = new DataColumn();
taxColumn.DataType = System.Type.GetType("System.Decimal");
//列名
taxColumn.ColumnName = "tax";
//設置該列得表達式，用於計算列中的值或建立聚合列
taxColumn.Expression = "price * 0.0862";
// Create third column.
DataColumn totalColumn = new DataColumn();
totalColumn.DataType = System.Type.GetType("System.Decimal");
totalColumn.ColumnName = "total";
//該列的表達式，值是獲得的是第一列和第二列值得和
totalColumn.Expression = "price + tax";

// 將全部的列添加到table上
table.Columns.Add(priceColumn);
table.Columns.Add(taxColumn);
table.Columns.Add(totalColumn);

//建立一行
DataRow row = table.NewRow();
//將此行添加到table中
table.Rows.Add(row);

//將table放在試圖中
DataView view = new DataView(table);
dg.DataSource = view;

dg.DataBind();