In this example we are going to describe how to implement RadioButtonList and DropDOwnList in Edit mode of GridVIew using EditItemTemaplate in ASP.NET C# and VB.NET.RadioButton and DropDOwnList are selected in edit mode based on value saved in DataBase

<asp:GridView ID="GridView1" runat="server" DataKeyNames="ID"
                      AutoGenerateColumns="False"                       DataSourceID="SqlDataSource1"
                      OnRowDataBound="GridView1_RowDataBound"
                      OnRowDataBound="GridView1_RowDataBound"
                      OnRowUpdated="GridView1_RowUpdated"
                      OnRowUpdating="GridView1_RowUpdating"
                      OnRowEditing="GridView1_RowEditing">
<Columns>
<asp:TemplateField HeaderText="ID">
<ItemTemplate>
<asp:Label ID="lblID" runat="server" Text='<%#Eval("ID") %>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="Name" HeaderText="Name"
                         SortExpression="Name" />
<asp:TemplateField HeaderText="Gender">
<ItemTemplate>
<asp:Label ID="lblGender" runat="server"
                 Text='<%#Eval("Sex") %>'>
</asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:RadioButtonList ID="rbGenderEdit" runat="server">
<asp:ListItem>Male</asp:ListItem>
<asp:ListItem>Female</asp:ListItem>
</asp:RadioButtonList>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Marital Status">
<ItemTemplate>
<asp:Label ID="lblStatus" runat="server"
                 Text='<%#Eval("MaritalStatus") %>'>
</asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropDownList ID="ddlStatusEdit" runat="server">
<asp:ListItem>Single</asp:ListItem>
<asp:ListItem>Married</asp:ListItem>
</asp:DropDownList>
</EditItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" />
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"/>
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [ID], [Name], [Sex], [MaritalStatus]
                          FROM [Details]"
UpdateCommand="Update Details Set [Name]=@Name, [Sex]=@Sex,
                          [MaritalStatus]=@MaritalStauts Where [ID]=@ID">
           <UpdateParameters>
           <asp:Parameter Name="Name" />
           <asp:Parameter Name="Sex" />
           <asp:Parameter Name="ID" />
           <asp:Parameter Name="MaritalStauts" />
           </UpdateParameters>
</asp:SqlDataSource>

protected void GridView1_RowDataBound(object sender,
GridViewRowEventArgs e)
{
     DataRowView dRowView = (DataRowView)e.Row.DataItem;
     if(e.Row.RowType == DataControlRowType.DataRow)
     {
          if((e.Row.RowState & DataControlRowState.Edit) > 0)
          {
               RadioButtonList rblGender =
                    (RadioButtonList)e.Row.FindControl("rbGenderEdit");
               DropDownList ddlStatus =
                    (DropDownList)e.Row.FindControl("ddlStatusEdit");
               rblGender.SelectedValue = dRowView[2].ToString();
               ddlStatus.SelectedValue = dRowView[3].ToString();
          }
     }
}
protected void GridView1_RowUpdating(object sender,
GridViewUpdateEventArgs e)
{
     RadioButtonList rblGender =
          (RadioButtonList)GridView1.Rows[e.RowIndex].FindControl("rbGenderEdit");
     DropDownList ddlStatus =
          (DropDownList)GridView1.Rows[e.RowIndex].FindControl("ddlStatusEdit");
     SqlDataSource1.UpdateParameters["Sex"].DefaultValue =
     rblGender.SelectedValue;
     SqlDataSource1.UpdateParameters["MaritalStauts"].DefaultValue =
          ddlStatus.SelectedValue;
}