2022年3月19日 星期六

[研究]DropDownList下拉選單的恩怨情仇(五)連動選單項目不存在的預選

 [研究]DropDownList下拉選單的恩怨情仇(五)連動選單項目不存在的預選

2022-3-19

環境：Visual Studio 2022 + ASP.NET + Web Application + WebForm + C#

續這篇

[研究]DropDownList下拉選單的恩怨情仇(一)'DropDownList1' 擁有的 SelectedValue 無效，因為它不在項目清單中。
https://shaurong.blogspot.com/2022/03/dropdownlistdropdownlist1-selectedvalue.html

[研究]DropDownList下拉選單的恩怨情仇(二)使用料庫儲存選項清單http://shaurong.blogspot.com/2022/03/dropdownlist.html

[研究]DropDownList下拉選單的恩怨情仇(三)已儲存項目不再提供於資料庫選項名單
http://shaurong.blogspot.com/2022/03/dropdownlist_19.html

[研究]DropDownList下拉選單的恩怨情仇(四)項目不存在的預選https://shaurong.blogspot.com/2022/03/dropdownlist_15.html

(下圖)新版分類選項

(下圖)舊版購買結果歷史紀錄 (芭樂、蘿蔔已經不再目前上面選項中)

Default2.aspx 


<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default2.aspx.cs"
    Inherits="WebApplication3.Default2" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
</head>
<body>
    <asp:SqlDataSource ID="SqlDataSource_FruitVegeType" runat="server"
        ConnectionString="<%$ ConnectionStrings:TestDBConnectionString %>"
        SelectCommand="SELECT N'' AS FruitVegeType UNION SELECT DISTINCT FruitVegeType FROM [FruitVegeList]"></asp:SqlDataSource>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server"
        ConnectionString="<%$ ConnectionStrings:TestDBConnectionString %>"
        SelectCommand="SELECT * FROM [FruitVegeRecord] WHERE ([sn] = @sn)"
        UpdateCommand="UPDATE [FruitVegeRecord] SET [FVType] = @FVType, [FruitBuy] = @FruitBuy WHERE [sn] = @sn">
        <SelectParameters>
            <asp:QueryStringParameter Name="sn" QueryStringField="sn" Type="Int32" DefaultValue="1" />
        </SelectParameters>
        <UpdateParameters>
            <asp:Parameter Name="FVType" Type="String" />
            <asp:Parameter Name="FruitBuy" Type="String" />
            <asp:Parameter Name="sn" Type="Int32" />
        </UpdateParameters>
    </asp:SqlDataSource>

    <form id="form1" runat="server">
        <div>
            <asp:DetailsView ID="DetailsView1" runat="server" Height="50px"
                DefaultMode="Edit" Caption="編輯"
                AutoGenerateRows="False" DataKeyNames="sn"
                DataSourceID="SqlDataSource1">
                <Fields>
                    <asp:BoundField DataField="sn" HeaderText="sn" InsertVisible="False" ReadOnly="True" SortExpression="sn" />
                    <asp:TemplateField HeaderText="FVType" SortExpression="FVType">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox_FVType" runat="server" Text='<%# Bind("FVType") %>' Visible="false"></asp:TextBox>
                            <asp:DropDownList ID="DropDownList_FruitVegeType" runat="server"
                                AutoPostBack="true" DataTextField="FruitVegeType"
                                DataValueField="FruitVegeType"
                                DataSourceID="SqlDataSource_FruitVegeType"
                                OnSelectedIndexChanged="DropDownList_FruitVegeType_SelectedIndexChanged">
                            </asp:DropDownList>
                            <asp:SqlDataSource ID="SqlDataSource_FruitVegeName" runat="server"
                                ConnectionString="<%$ ConnectionStrings:TestDBConnectionString %>"
                                SelectCommand="SELECT N'' AS FruitVegeName UNION (SELECT FruitVegeName FROM [FruitVegeList] WHERE ([FruitVegeType] = @FruitVegeType))">
                                <SelectParameters>
                                    <asp:ControlParameter ControlID="DropDownList_FruitVegeType" Name="FruitVegeType" ConvertEmptyStringToNull="false" PropertyName="SelectedValue" />
                                </SelectParameters>
                            </asp:SqlDataSource>
                        </EditItemTemplate>
                    </asp:TemplateField>
                    <asp:TemplateField HeaderText="FruitBuy" SortExpression="FruitBuy">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox_FruitBuy" runat="server" Text='<%# Bind("FruitBuy") %>' Visible="false"></asp:TextBox>
                            <asp:DropDownList ID="DropDownList_FruitVegeName" runat="server"
                                DataSourceID = "SqlDataSource_FruitVegeName"
                                AutoPostBack="true" DataTextField="FruitVegeName"
                                DataValueField="FruitVegeName"
                                OnSelectedIndexChanged="DropDownList_FruitVegeName_SelectedIndexChanged">
                                <asp:ListItem></asp:ListItem>
                            </asp:DropDownList>
                        </EditItemTemplate>
                    </asp:TemplateField>
                    <asp:CommandField ShowEditButton="True" />
                </Fields>
            </asp:DetailsView>
        </div>
    </form>
</body>
</html>

Default2.aspx.cs 中部分


using System;
using System.Web.UI.WebControls;

namespace WebApplication3
{
    public partial class Default2 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }
        protected void DropDownList_FruitVegeType_SelectedIndexChanged(object sender, EventArgs e)
        {
            TextBox TextBox_FVType = (TextBox)DetailsView1.FindControl("TextBox_FVType");
            DropDownList DropDownList_FruitVegeType = (DropDownList)DetailsView1.FindControl("DropDownList_FruitVegeType");
            TextBox_FVType.Text = DropDownList_FruitVegeType.SelectedValue;
        }
        protected void DropDownList_FruitVegeName_SelectedIndexChanged(object sender, EventArgs e)
        {
            TextBox TextBox_FruitBuy = (TextBox)DetailsView1.FindControl("TextBox_FruitBuy");
            DropDownList DropDownList_FruitVegeName = (DropDownList)DetailsView1.FindControl("DropDownList_FruitVegeName");
            TextBox_FruitBuy.Text = DropDownList_FruitVegeName.SelectedValue;
        }
    }
}

按下「編輯」按鈕後出現


(完)

張貼者： 於
標籤： ,

沒有留言:

張貼留言

訂閱： 張貼留言 (Atom)