如何将 二级联动dropdownlist与新增一行结合在一起使用？

Question

我要实现的功能是在一个表中插入数据，初始化时只有一行，点击新增按钮表会自动新增一行，可以插入新数据。
现在问题是要在每一行都有两个dropdownlist，这两个dropdownlist是二级联动的。该怎么实现？  aspx代码:
  <asp:HiddenField ID="HDListNum" runat="server" />
                        <table id="tableLike" style="border-color: #C1DAD7; border-width: 1px; border-style: solid;"
                            cellspacing="0">
                            <tr align="center" style="background-color: #999999">
                                <td class="td">
                                    喜好类型
                                </td>
                                <td class="td">
                                    喜好内容
                                </td>
                                <td class="td">
                                    备注
                                </td>
                            </tr>
                            <%  
                                int perToal2 = Convert.ToInt32(this.HDListNum.Value.Trim());
                                for (int i = 0; i < perToal2; i++)
                                { 
                            %>
                            <tr>
                                <td valign="middle" class="td">
                                    <asp:DropDownList ID="editDDLikesType" runat="server" Width="90px" OnSelectedIndexChanged="LikesType_SelectedIndexChanged"
                                        AutoPostBack="True">
                                        <asp:ListItem Value="--请选择--">--请选择--</asp:ListItem>
                                        <asp:ListItem Value="烟">烟</asp:ListItem>
                                        <asp:ListItem Value="酒">酒</asp:ListItem>
                                        <asp:ListItem Value="食">食</asp:ListItem>
                                        <asp:ListItem Value="购物">购物</asp:ListItem>
                                        <asp:ListItem Value="兴趣爱好">兴趣爱好</asp:ListItem>
                                    </asp:DropDownList>
                                </td>
                                <td valign="middle" class="td">
                                    <asp:DropDownList ID="ddDrink1" runat="server" AutoPostBack="true">
                                    </asp:DropDownList>
                                </td>
                                <td valign="middle" class="td">
                                    <input name="namesNotes" type="text" id="txtNotes" runat="server" />
                                </td>
                            </tr>
                            <%  }  %>
                            <tr>
                                <td>
                                    <asp:Button ID="btnAddList" runat="server" Text="新增" OnClick="AddList" />
                                </td>
                            </tr>
                        </table>cs代码：        public void AddList(object sender, EventArgs e)
        {
            int perToal = Convert.ToInt32(this.HDListNum.Value.Trim());
            perToal++;
            if (perToal > 7)
            {
                perToal = 7;
            }
            this.HDListNum.Value = Convert.ToString(perToal);
        }

Answer 1

仅供参考 还有些问题没有考虑 比如删到一行都不剩<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowDataBound="GridView1_RowDataBound">
            <Columns>
                <asp:TemplateField HeaderText="喜好类型">
                    <ItemTemplate>
                        <asp:DropDownList ID="editDDLikesType" runat="server" Width="90px" OnSelectedIndexChanged="editDDLikesType_SelectedIndexChanged"
                            AutoPostBack="true">
                            <asp:ListItem Value="--请选择--">--请选择--</asp:ListItem>
                            <asp:ListItem Value="烟">烟</asp:ListItem>
                            <asp:ListItem Value="酒">酒</asp:ListItem>
                            <asp:ListItem Value="食">食</asp:ListItem>
                            <asp:ListItem Value="购物">购物</asp:ListItem>
                            <asp:ListItem Value="兴趣爱好">兴趣爱好</asp:ListItem>
                        </asp:DropDownList>
                        <asp:HiddenField ID="HiddenField1" runat="server" Value='<%# Eval("str1") %>' />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="喜好内容">
                    <ItemTemplate>
                        <asp:DropDownList ID="ddDrink1" runat="server">
                        </asp:DropDownList>
                        <asp:HiddenField ID="HiddenField2" runat="server" Value='<%# Eval("str2") %>' />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="备注">
                    <ItemTemplate>
                        <asp:TextBox ID="TextBox1" runat="server" Text='<%# Eval("str3") %>'></asp:TextBox>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="">
                    <ItemTemplate>
                       <asp:Button ID="Button1" runat="server" Text="添加行" OnClick="Button1_Click" />
                       <asp:Button ID="Button2" runat="server" Text="删除行" OnClick="Button2_Click" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                DataTable dt = new DataTable();
                dt.Columns.Add("str1");
                dt.Columns.Add("str2");
                dt.Columns.Add("str3");
                DataRow dr = dt.NewRow();
                dt.Rows.Add(dr);
                this.GridView1.DataSource = dt;
                this.GridView1.DataBind();
            }
        }
        protected void Button1_Click(object sender, EventArgs e)
        {
            int row = ((GridViewRow)((Button)sender).NamingContainer).RowIndex;            DataTable dt = new DataTable();
            dt.Columns.Add("str1");
            dt.Columns.Add("str2");
            dt.Columns.Add("str3");
            foreach (GridViewRow item in this.GridView1.Rows)
            {
                DataRow dr = dt.NewRow();
                dr["str1"] = (item.Cells[0].FindControl("editDDLikesType") as DropDownList).SelectedValue;
                dr["str2"] = (item.Cells[1].FindControl("ddDrink1") as DropDownList).SelectedValue;
                dr["str3"] = (item.Cells[2].FindControl("TextBox1") as TextBox).Text;
                dt.Rows.Add(dr);
            }
            dt.Rows.InsertAt(dt.NewRow(), row + 1);            this.GridView1.DataSource = dt;
            this.GridView1.DataBind();
        }        protected void Button2_Click(object sender, EventArgs e)
        {
            int row = ((GridViewRow)((Button)sender).NamingContainer).RowIndex;            DataTable dt = new DataTable();
            dt.Columns.Add("str1");
            dt.Columns.Add("str2");
            dt.Columns.Add("str3");
            foreach (GridViewRow item in this.GridView1.Rows)
            {
                DataRow dr = dt.NewRow();
                dr["str1"] = (item.Cells[0].FindControl("editDDLikesType") as DropDownList).SelectedValue;
                dr["str2"] = (item.Cells[1].FindControl("ddDrink1") as DropDownList).SelectedValue;
                dr["str3"] = (item.Cells[2].FindControl("TextBox1") as TextBox).Text;
                dt.Rows.Add(dr);
            }
            dt.Rows.RemoveAt(row);
            this.GridView1.DataSource = dt;
            this.GridView1.DataBind();
        }
        protected void editDDLikesType_SelectedIndexChanged(object sender, EventArgs e)
        {
            DropDownList dl = sender as DropDownList;
            int row = ((GridViewRow)((DropDownList)sender).NamingContainer).RowIndex;
            DropDownList dl2 = this.GridView1.Rows[row].Cells[1].FindControl("ddDrink1") as DropDownList;
            dl2.Items.Clear();
            if (dl.SelectedValue!="--请选择--")
            {
                dl2.Items.Add(new ListItem(dl.SelectedValue + "1", dl.SelectedValue + "1"));
                dl2.Items.Add(new ListItem(dl.SelectedValue + "2", dl.SelectedValue + "2"));
                dl2.Items.Add(new ListItem(dl.SelectedValue + "3", dl.SelectedValue + "3"));
                dl2.Items.Add(new ListItem(dl.SelectedValue + "4", dl.SelectedValue + "4"));
            }
            
        }        protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                (e.Row.Cells[0].FindControl("editDDLikesType") as DropDownList).SelectedValue = (e.Row.Cells[0].FindControl("HiddenField1") as HiddenField).Value;
                DropDownList dl1 = e.Row.Cells[0].FindControl("editDDLikesType") as DropDownList;
                DropDownList dl2 = e.Row.Cells[1].FindControl("ddDrink1") as DropDownList;
                if (dl1.SelectedValue != "--请选择--")
                {
                    dl2.Items.Add(new ListItem(dl1.SelectedValue + "1", dl1.SelectedValue + "1"));
                    dl2.Items.Add(new ListItem(dl1.SelectedValue + "2", dl1.SelectedValue + "2"));
                    dl2.Items.Add(new ListItem(dl1.SelectedValue + "3", dl1.SelectedValue + "3"));
                    dl2.Items.Add(new ListItem(dl1.SelectedValue + "4", dl1.SelectedValue + "4"));
                }
                dl2.SelectedValue = (e.Row.Cells[1].FindControl("HiddenField2") as HiddenField).Value;
            }
        }