因为tb1 = null Table[] tb1 = new Table[n];
tb1[0].CssClass = "table";
item_div.Controls.Add(tb1[0]);或者 Table tb1 = new Table();
tb1.CssClass = "table";
item_div.Controls.Add(tb1);
tb1[0].CssClass = "table";
item_div.Controls.Add(tb1[0]);或者 Table tb1 = new Table();
tb1.CssClass = "table";
item_div.Controls.Add(tb1);
Table[] tb1 = new table[9];
tb1[0] = new Table();
tb1[0].CssClass = "table";
item_div.Controls.Add(tb1[0]);
也不行