.net 创建一个页面级全局datatable的方法

public DataTable dtitem
    {
        get { return (DataTable)ViewState["dtitem"]; }
        set { ViewState["dtitem"] = value; }
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        //return;
        if (!Page.IsPostBack)
        {
            DataTable dt1 = new DataTable();
            dt1.Columns.Add("item_code", typeof(string));
            dt1.Columns.Add("item_name", typeof(string));
            dt1.Columns.Add("item_price", typeof(float));
            dt1.Columns.Add("item_codeAnPrice", typeof(string));
            dtitem = dt1;
        }
    }