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Create an asp server control dynamically in an html string, which is then inserted in an aspx

I am on the server side of an asp.net application. There I have some html source code in a variable called 'HtmlText'. This source code is generated from xml via a xsl transformation, and is resulting in something like this:
<h1>ABC Test KH</h1>
<!--place for the control-->
<table class="tablesorter" id="tablesorter183">
<thead>
<tr>
<th align="left">Name</th>
<th align="right">DB</th>
<th align="right">DB Anteil in Prozent</th>
<th align="right">ABC</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left" fieldName="Name">Fabrikam, Inc.</td>
<td align="right" fieldName="DB">881.378,00 €</td>
<td align="right" fieldName="DB_Anteil_in_Prozent">29,92</td>
<td align="right" fieldName="ABC">A</td>
</tr>
</tbody>
</table>
Now this source code is inserted in a aspx-website via the InnerHtml-property.
There is a div with id 'book' in that aspx:
book.InnerHtml = HtmlText
This works fine so far.
But now I want to create a dropdown-control in that html, which I can access on server-side. This control should be placed between the h1 and table-tags, where the comment <!--place for the control--> is located.
I know how to create asp-control dynamically and bind an event to that, but this works only if I have the aspx in the first place. I cannot do that to some html-source which exists just in a string at that time.
Is there any way to do what I want, or am I on the wrong track here?
Thanks in advance for any suggestions.
Kind regards,
Kai

I think the only solution is to create a control that inherits DropDownList, and override its RenderControl method.
Something like this:
public override void RenderControl(HtmlTextWriter writer)
{
//...
//Fill in the variable HtmlText content
//Split it to 2 variables - before and after the control place, and:
writer.Write(startString);
base.RenderControl(writer);
writer.Write(endString);
}
And use this control instead of DropDownList.
EDIT: In a case of several controls, I would use the way suggested here: Render .net controls to string and get events to fire:
Split the string to several strings - the first string - from the beginning to the first control, second string - from the first control to the second control, and so on.
And then insert each of the strings to a new LiteralControl, and add them to the page Like this:
book.Controls.Add(LiteralControl1);
book.Controls.Add(DropDownList1);
book.Controls.Add(LiteralControl2);
book.Controls.Add(Button1);

Given a web response, how do I extract a specific portion for further processing?

I have some code that gets a web response. How do I take that response and search for a table using its CSS class (class="data")? Once I have the table, I need to extract certain field values. For example, in the sample markup below, I need the values of Field #3 and Field #5, so "85" and "1", respectively.
<table width="570" border="0" cellpadding="1" cellspacing="2" class="data">
<tr>
<td width="158"><strong>Field #1:</strong></td>
<td width="99">1</td>
<td width="119"><strong>Field #2:</strong></td>
<td width="176">110</td>
</tr>
<tr>
<td width="158"><strong>Field #3:</strong></td>
<td width="99">85</td>
<td width="119"><strong>Field #4:</strong></td>
<td width="176">-259.34</td>
</tr>
<tr>
<td width="158"><strong>Field #5:</strong></td>
<td width="99">1</td>
<td width="119"><strong>Field #6:</strong></td>
<td width="176">110</td>
</tr>
<tr>
<td width="158"><strong>Field #7:</strong></td>
<td width="99">12</td>
<td width="119"><strong>Field #8:</strong></td>
<td width="176">123.23</td>
</tr>
</table>

Use the HTML Agility Pack and parse the HTML. If you want to do it the simplest way then go grab its beta (it supports LINQ).

As Randolf suggests, using HTML Agility Pack is a good option.
But, if you have control of the format of the HTML, it is also possible to do string parsing to extract the values you are after.
It is nearly trivial to download the entire HTML as a string and search for the string "<table" followed by the string "class=\"data\"". Then you can easily extract the values you are after by doing similar string manipulations.
I'm not saying you should do this, for the resulting code will be harder to read and maintain that the code using HTML Agility Pack, but it will save you an external dependency and your code will probably perform much better.
In a WP7 app I made, I started using HTML Agility Pack to parse some HTML and extract some values. This worked well, but it was quite slow. Switching to the string parsing regime made my code many times faster while returning the exact same result.

Create Dynamical Div tag in ASP.Net

I am developing Web Application. In that i am using so many Div to open pop ups. Now my requirement is to create dynamic Div for that popup and all the content of that div comes from the Database.
So can anyone tell me how to create Div dynamically programatically?
My Sample code for Div..
<div id="Popup" runat="server" class="hidden-content">
<table width="auto">
<tr>
<td style="font-size: 20px; font-weight: bold; text-align: center;">
<p>
</p>
<b>Diabetes</b>
</td>
</tr>
<tr>
<td style="font-size: 15px; text-align: left;">
<p>
Type I diabetes (also known as juvenile diabetes) is the less common form of diabetes.
It usually is diagnosed during childhood or teen years and requires treatment with
insulin.
</p>
</td>
</tr>
</table>
</div>

I would insert either a PlaceHolder or a Literal control into you page and insert the html controls/text on PageLoad or PageRender.
If you use the Placeholder control you can create the content using the HTML controls in System.Web.UI.HtmlControls.
By using the Placeholder control, you could also write a custom WebControl that you could re-use in other locations within your site. This could then be added to the placeholder control at runtime.
For a liteal, you can just append the control div HTML as text.

you can add html using stringbuilder
Use below cose to add html programmatically.
using System.Text;
StringBuilder strdiv = new StringBuilder();
strdiv.Append("Put your Html here");
strdiv.Append("Add much as you want ");
after that assign that stringbuilder to label so get one label in html with id "htmllabel"
Add below line to append html in your label.
htmllabel.Text = strdiv.ToString();

You need to use the defined server control called asp:Panel, which gets rendered as a div. Create your panels programatically and add them to your page: e.g. Page.Controls.Add(myPanel);

I was working on a web application in which i need same thing as you require from here you will get some idea and make some modifications as per your requirement.Check my article here
If you have any doubt then ask.
Thanks :-)

How to fix table's column empty space in firefox?

This is inline code of a .aspx page:-
<table>
<tr>
<td>Some static data</td>
<td>Text box control</td>
<td><div id="div1"></div></td>
</tr>
</table>
Third <td> has a div 'div1'. This div does not have any data most of time on that page. But sometimes i need to display some dynamic data there). Now problem is, if there is no data in div 'div1', firefox consider it as a space in it and takes approx. 5px space in browser. (But IE8 in compatibility view is fine)
What is the work around here for firefox?

I'd consider if you actually need the div - I guess you are filling it with data in certain circumstances by targetting the ID, by why not just target the table cell instead?
<table>
<tr>
<td>Some static data</td>
<td>Text box control</td>
<td id="div1"></td>
</tr>
</table>

Try setting all margins and padding to 0 at the start of your CSS.
*{
margin: 0;
padding: 0;
}
And then you can set those values explicitly where required.

That's because you have a padding applied to the td elements. You could do this: <td style="padding:0"><div id="div1" style="display:none; padding:1px;"></td>
And shift the padding to the div element and the hide it when it is empty. Firefox doesn't apply any padding to it in that case. But, it should still look like other tds when there is data applied to it.

It sounds like you need to reset your styles. There's a couple of good ones out there including Eric Meyer's CSS reset and Yahoo YUI2 CSS reset.

HTML template for ASP controls

I am writing an application that requires that my customer can layout their input forms in which ever way they choose.
I would like to use an HTML template with placeholders, and then replace these with secified .NET controls at runtime:
<table style="width: 100%;">
<tr>
<td colspan="2">
<fieldset title="Customers Template" >
<table style="width:100%;">
<tr>
<td width="140">
Policy Number:</td>
<td width="150">
$$Policy Number$$</td>
<td colspan="2" rowspan="3" valign="top">
Type 1:<br />
$$Type 1$$</td>
<td rowspan="3" valign="top">
Info:<br />
$$Info$$</td>
<td rowspan="3" valign="top">
Problems:<br />
$$Problems$$</td>
</tr>...
So I want to find and replace my $$xxx$$ text with various .NET controls, depending on the datatype of the field being added, at runtime.
Any suggestions on good ways to approach this?
Thanks,
Mark

Replace your $$xxx$$ blocks with <asp:PlaceHolder> controls.
At runtime you can parse the template
--- In the most simplest case, you can require the template be valid xhtml, then you can simply use the .NET XML APIs to iterate through all the ChildNodes of the XmlDocument. From each element build the appropriate ASP.NET Server control.
For a more complex (and complete HTML parser) see http://www.developer.com/net/csharp/article.php/2230091
As you parse, wherever you see <asp:PlaceHolder> - replace that with your logic that defines your template.
Tutorial: http://www.devhood.com/tutorials/tutorial_details.aspx?tutorial_id=752

If you're going to replace these placeholders with only strings take a look at NVelocity template engine. In this answer, I simply show how you can create an email by a template.
But for asp.net server controls, you can split your html template into chunks, and add them to your page as LiteralControl like that :
Page.Controls.Add(new LiteralControl(#"<td width='140'>
Policy Number:</td>
<td width='150'>"));
Page.Controls.Add(textBox1);
Page.Controls.Add(new LiteralControl(#"</td><td colspan='2' rowspan='3' valign='top'>
Type 1:<br />"));