Question

我必须在内容页面中找到一个面板，并且需要在该面板上添加一个下拉列表。我已经搜索过，但我只是将控件添加到母版页.Below是我的代码，注意：我必须从该页面添加控件而不是从母版页

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Salesorder.aspx.cs" Inherits="Salesorder" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
    <script src="assets/plugins/jquery-1.10.2.js"></script>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
  <div class="row">
<asp:Panel ID="Panel1" runat="server"> 
</asp:Panel>             
        </div>
</asp:Content>

我需要从codebehind为Panel1添加另一个面板。

    protected void Page_PreInit(object sender, EventArgs e)
       {
          //Create a Dynamic Panel
          Panel pnlDropDownList; 
          pnlDropDownList = new Panel();
          pnlDropDownList.ID = "pnlDropDownList";
          pnlDropDownList.BorderWidth = 1;
          pnlDropDownList.Width = 300;
          ContentPlaceHolder cph = (ContentPlaceHolder)this.Page.FindControl("ContentPlaceHolder1");
          Panel panel = (Panel)cph.FindControl("Panel1");
          cph.Controls.Add(pnlDropDownList);
       }

Answer 1

是的，您需要在Master中找到您的控件而不是Page。

如下所示。

public static void Update_to_DB() throws SQLException, IOException {
    String URL = "jdbc:ucanaccess://C:\\Users\\bharat.nanwani\\Desktop\\Images.accdb";
    Connection conn = DriverManager.getConnection(URL);
    //Statement stmt = conn.createStatement();
    PreparedStatement p;

    File ImgPath = new File("C:\\Users\\bharat.nanwani\\Desktop\\Desert.jpg");
    FileInputStream fin = new FileInputStream(ImgPath);
    String query = "INSERT INTO Images(Data) VALUES(?);";
    p = conn.prepareStatement(query);
    p.setBinaryStream(1, fin);
    p.execute();
}

public static void update_to_DISK() throws SQLException, IOException {
    String URL = "jdbc:ucanaccess://C:\\Users\\bharat.nanwani\\Desktop\\Images.accdb";
    Connection conn = DriverManager.getConnection(URL);
    PreparedStatement p;
    ResultSet rs;
    String query = "SELECT Data FROM Images";
    p = conn.prepareStatement(query);
    rs = p.executeQuery();
    if (rs.next()) {
        byte[] bytearray = rs.getBytes("Data");
        FileOutputStream fos = new FileOutputStream("C:\\Users\\bharat.nanwani\\Desktop\\New Folder\\test.jpg");
        fos.write(bytearray);
        fos.close();
        System.out.println(bytearray);
    }
}

这应该有效。

Answer 2

在面板中添加一个PlaceHolder控件，希望在aspx页面中添加新的DropDownList面板

<asp:Panel ID="Panel1" runat="server"> 
    <asp:PlaceHolder ID="placeholder1" runat="server"></PlaceHolder>
</asp:Panel>

在后面的代码中，要将控件添加到页面使用：

placeholder1.Controls.add(pnlDropDownList);

Answer 3

我无法理解为什么不添加像这样的控件

<asp:ContentPlaceHolder id="ContentPlaceHolder1" runat="server">
        <asp:Panel ID="Panel1" runat="server">
            <asp:DropDownList ID="DropDownList1" runat="server"></asp:DropDownList>
        </asp:Panel>
    </asp:ContentPlaceHolder>

如何在内容页面中添加面板？

3 个答案: