Question

How I can create dynamic GridView with dynamic number of row When click on button

and put in one column DropDownList .

Answer 1

Your question is pretty brief, but if if i think i understand what you want to do, you could try this:

in the codebehind of your button

List<string> ThisIsYourList = new List<string>();
Gridview1.DataSource = ThisIsYourList;
Gridview1.DataBind();

if you want to add a dropdownlist to every row, you need to add an itemtemplate to your gridview like this:

   <asp:TemplateField>
   <ItemTemplate>
   <asp:DropDownList ID="DropDownList1" runat="server"/>
   </ItemTemplate>
   </asp:TemplateField>

You add this itemtemplate anywhere between the tags of your gridview.