vb: CType(obj,TextBox) CType(Sender,Control)
例如 : Dim tb1 As TextBox = CType(e.Item.Cells(1).Controls(1), TextBox)
c#: (TextBox)obj
例如 : TextBox tb = (TextBox) e.Item.Cells[2].Controls[0];
TextBox tb = (TextBox) e.Item.Cells[2].Controls.FindControl("TextBoxID");
Object o;
TextBox tb = (TextBox)o;
TextBox tb2 = o as TextBox;