How to add textbox,ddl in grid view

You can to use GridView Template Field for adding TextBox or any other ASP.NET Controls.

<asp:GridView ID="GridView1" runat="server">
        <Columns>
            <asp:TemplateField>
                <ItemTemplate>
                    <asp:DropDownList>
                        <asp:ListItem Text="text" />
                    </asp:DropDownList>
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
    </asp:GridView>

Read Here About TemplateField[^]

You can Bind the using BindExpression in aspx or you can using FindControl from code behind to get the control details.

Hope this will help.

first of all... you create the object of datagridviewTextBoxcolumn and then add this object control in the datagridview.
..................................

Dim txt As New DataGridViewTextBoxColumn()
        DataGridView1.Columns.Add(txt)
        txt.HeaderText = "Click Data"
        txt.Text = "Click Here"
        txt.Name = "btn"
        txt.UseColumnTextForButtonValue = True