Dynamically adding images using UpdatePanel

StackOverflow https://stackoverflow.com/questions/16432331

Question

I'm trying to dynamically create images in a table but it seems like the UpdatePanel is not updating. I have the following code in my .aspx page.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ViewTile.aspx.cs" Inherits="ViewTile" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
        <title></title>
    </head>
    <body runat="server">
        <form id="form1" runat="server">
            <div>
                <asp:Image ID="tileImg" runat="server"/>
                <asp:ScriptManager ID="ScriptManager1" runat="server"/>
                <table>
                    <asp:updatePanel ID="UpdatePanel1" runat="server">
                        <ContentTemplate>
                            <asp:PlaceHolder runat="server" ID="placeholder1"/>
                        </ContentTemplate>
                    </asp:updatePanel>
                </table>        
            </div>
        </form>
    </body>
</html>

And then this this the aspx.cs page.

TableRow imageRow = new TableRow();

for (int rowItr = 0; rowItr < 3; rowItr++)
{
    for (int colItr = 0; colItr < 4; colItr++)
    {
        System.Web.UI.WebControls.Image image = new System.Web.UI.WebControls.Image();
        image.ImageUrl = "~/ShowTile.ashx?SheetId=" + SheetGUID + "&Scale=" + 3
            + "&XCoord=" + colItr + "&YCoord=" + rowItr;
        placeholder1.Controls.Add(image);
        TableCell imageCell = new TableCell();
        imageCell.Controls.Add(image);
        imageRow.Cells.Add(imageCell);
    }

    placeholder1.Controls.Add(imageRow);
    imageRow.Cells.Clear();
}

I know for a fact that the image is being called correctly as I've outputted it manually using an image tag on the client. Any help would be great! Thanks

Was it helpful?

Solution

You need to add Table first, add rows to it and finally add table to placeholder1.Controls

Table tbl= new Table();
for (int rowItr = 0; rowItr < 3; rowItr++)
{
    TableRow imageRow = new TableRow();
    for (int colItr = 0; colItr < 4; colItr++)
    {

        System.Web.UI.WebControls.Image image = new System.Web.UI.WebControls.Image();
        image.ImageUrl = "~/ShowTile.ashx?SheetId=" + SheetGUID + "&Scale=" + 3
            + "&XCoord=" + colItr + "&YCoord=" + rowItr;
        TableCell imageCell = new TableCell();
        imageRow.Cells.Add(imageCell);            
    }
    tbl.Rows.Add(imageRow);
}
placeholder1.Controls.Add(tbl);

OTHER TIPS

You Can Do this using javascript and Web Service.

Create a function that Call Web Service and fetch url of the image and append it into the update panel div

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