将asp.net图像添加到div

Question

有没有一种方法可以在下面的代码中动态地将 Image1 添加到 while 循环中（包含在 div 中）我的意思是实际上将 asp 图像添加到 div 中？通过代码。目前，当我看到它时，代码会寻找一个 asp 图像，但我没有看到你可以将它“添加”到我的动态内容中：

using (OdbcCommand cmd = new OdbcCommand("SELECT Wallpostings FROM WallPosting WHERE UserID=" + userId + " ORDER BY idWallPosting DESC", cn))
{
    using (OdbcDataReader reader = cmd.ExecuteReader())
    {
        var divHtml = new System.Text.StringBuilder();
        while (reader.Read())
        {
            divHtml.Append("<div id=test>");
            divHtml.Append(String.Format("{0}", reader.GetString(0)));
            divHtml.Append("</div>");
        }
        test1.InnerHtml = divHtml.ToString();
    }
}

我以为我有这个：

        var divHtml = new System.Text.StringBuilder();
        while (reader.Read())
        {
                    divHtml.Append("<div id=test>");
                    divHtml.Append(String.Format("{0}", reader.GetString(0)));
                    Image img = new Image();
                    img.ImageUrl = "~/userdata/2/uploadedimage/batman-for-facebook.jpg";
                    divHtml.Append(img);
                    divHtml.Append("</div>");
        }
        test1.InnerHtml = divHtml.ToString();

我得到了一个时髦的输出吗？

看图：

我也试过这个：

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Data.Odbc;
    using System.Web.UI.WebControls.Image;
    using System.Web.UI.HtmlControls.HtmlGenericControl;
    using System.IO;

    public partial class UserProfileWall : System.Web.UI.Page
    {

        protected void Page_Load(object sender, EventArgs e)
        {
            string theUserId = Session["UserID"].ToString();
            PopulateWallPosts(theUserId);
        }
        public static string RenderHtmlString(this System.Web.UI.HtmlControls.HtmlGenericControl htmlControl)
        {
            string result = string.Empty;
            using (System.IO.StringWriter sw = new System.IO.StringWriter())
            {
                var writer = new System.Web.UI.HtmlTextWriter(sw);
                htmlControl.RenderControl(writer);
                result = sw.ToString();
                writer.Close();
            }
            return result;
        }
        private void PopulateWallPosts(string userId)
        {
            using (OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=root; Password=commando;"))
            {
                cn.Open();
                using (OdbcCommand cmd = new OdbcCommand("SELECT Wallpostings FROM WallPosting WHERE UserID=" + userId + " ORDER BY idWallPosting DESC", cn))
                {
                    using (OdbcDataReader reader = cmd.ExecuteReader())
                    {


                        var divHtml = new System.Text.StringBuilder();
                        while (reader.Read())
                        {
                            using (StringWriter sw = new StringWriter())

                            divHtml.Append("<div id=test>");
                            divHtml.Append(String.Format("{0}", reader.GetString(0)));
                            Image img = new Image();
                            img.ImageUrl = "~/userdata/2/uploadedimage/batman-for-facebook.jpg";
                            divHtml.Append(img.RenderHtmlString());
//this line
                            divHtml.Append("</div>");
                        }
                        test1.InnerHtml = divHtml.ToString();
                    }
                }
            }
        }

但是 RenderHtmlString 没有定义？

Answer 1

HtmlGenericControl("div") divHtml = new HtmlGenericControl("div");
divHtml.Controls.Add( HtmlImage image = new HtmlImage{ Src = "pathgoeshere" } );

大概您还需要将其作为字符串返回？如果是这样，试试这个方便的 Generic http://www.refactory.org/s/render_html_string_from_htmlgenericcontrol/view/latest，但要真正按照其他人的建议去做，并充分利用 <asp:PlaceHolder 的力量，只需将此返回的控件添加到占位符的控件集合中即可。

Answer 2

不，您不能将服务器控件添加到 DOM 元素的文字表示中。

我不确定“test1”是什么类型的控件，但您应该将其更改为 PlaceHolder 控件并执行以下操作（未经测试！）：

 using (OdbcCommand cmd = new OdbcCommand("SELECT Wallpostings FROM WallPosting WHERE UserID=" + userId + " ORDER BY idWallPosting DESC", cn))
        {
            using (OdbcDataReader reader = cmd.ExecuteReader())
            {
                var divHtml = new System.Text.StringBuilder();
                while (reader.Read())
                {
                    System.Web.UI.HtmlControls.HtmlGenericControl div = new System.Web.UI.HtmlControls.HtmlGenericControl("div");
                    div.ID = "test";
                    div.InnerHtml = String.Format("{0}", reader.GetString(0));
                    Image img = new Image();
                    img.ImageUrl = "~/images/test.jpg";
                    img.AlternateText = "Test image";
                    div.Controls.Add(img);
                    test1.Controls.Add(div);
                }
                test1.InnerHtml = divHtml.ToString();
            }
        }

希望这会有所帮助！

Answer 3

只是有点担心。您正在动态构建 SQL 字符串。确保清理“userid”变量。

您可以通过这样做来动态创建图像：

System.Web.UI.WebControls.Image img = new Image();
img.ImageUrl = "~/img/image1.jpg";

您是否已经知道要使用的图像？图片或图片源是否位于您的数据库中？

Answer 4

尝试使用占位符

Image img = new Image(); // instantiating the control
img.ImageUrl = "~/myimage.gif"; // setting the path to the image
placeholderpicture.Controls.Add(img);

来自http://forums.asp.net/t/1308158.aspx/1