Hi,

I am creating a custom control in C#. this control will have a radcomboBox and lable in a html table. When you select an item in the radcomboBox, the selected item text will be diplayed in the lable. But when I try to render, I am getting error.

Page cannot be null. Please ensure that this operation is being performed in the context of an ASP.NET request.

RadComboBox

currencySelector = new RadComboBox();
currencySelector.ID = "dsfdsf";
//currencySelector.Items.Add(new Telerik.Web.UI.RadComboBoxItem("Australian"));
htmltableCell.Controls.Add(currencySelector);
htmlTableRow.Cells.Add(htmltableCell);
.....
currencyConverterTable.Rows.Add(htmlTableRow)
currencyConverterTable.RenderControl(output);

What am I doing wrong here???

Thanks,

Toby

Hi Taeho Yoo,

You are not adding the combobox in the controls collection of the Page (or the controls collection of any other control already added to the Page).

Regards,
Albert
the Telerik team

Thank you so much for your reply but could you give me some more information please? I don't really get it :(

Thanks

Hi Taeho Yoo,

You need to add the currencyConverterTable to the controls collection of something already in the page e.g. the form:

Page.Form.Controls.Add(currencyConverterTable);

You can find additional info in this blog post.

Regards,
Albert
the Telerik team

Is there any way to get the ColorPicker to render without a page?

I had to add it in a situation where I write directly in the aspx, not aspx.cs.

Also, I might need to do it from a generic handler, ashx.

Is this possible?

Hello David,

The control needs to be added to a page, either in its markup, or in its code-behind. You could try the RenderControl method and write to Response.OutputStream, yet this is not a supported scenario and it success cannot be guaranteed, so I advise against such attempts.

Regards,
Marin
the Telerik team

Hello I'm using Telerik.Web.UI Telerik chart to generate images. 

radchart.Save throws object not initialised error 

ScriptManager {"Page cannot be null. Please ensure that this operation is being performed in the context of an ASP.NET request."} System.InvalidOperationException
This works ok from web and my unit tests, but when I access using windows service it fails? with 

throws object not initialised error stack trace points to save method. 

any help will be appreciated. 

ta

Hi Vijay,

Can you please provide more details about the problem? Here is what worked fine on my end. The code looks like this:


And the project has references to System.Web and System.Web.Extensions assemblies (needed by RadChart). You can find the resulting file attached.

Best regards,
Ves
the Telerik team

Marin,

Is there any way to accomplish what David is attempting to do, yet?  We have a client that is wanting gauges in one of our Telerik.Reporting reports which we export to HTML.  I would like to be able to create a placeholder in the report itself, then once the report was rendered, replace the placeholder with a gauge, server-side.  Is that not possible with any products you offer?  We're not using the report viewer, either - simply the ReportRenderer.

Thanks,
Adam

Hi  Adam,

Could you confirm whether you need to embed data in an aspx page renderd in a browser, or are you generating a report? For the latter, perhaps the Telerik Reporting will be a more suitable tool rather than tampering with the rendered HTML from ASPX pages.

On the question whether an ASP.NET AJAX script control can render without a page, then be added somewhere (not to mention - continue functioning there) - this is not possible, nor will it be. IScriptControls require the server lifecycle of the webform page and a Scriptmanager to register their resources, then the MS AJAX client-side scripts to generate their $create() statements and instantiate their client-side objects, so they can work. This cannot happen without a page.

If you are looking for widgets that you can easily create dynamically - perhaps the JavaScript Kendo UI framework will be of interest, because it only needs its scripts in the browser, from this point on you can create HTML elements and instantiate widgets over them without going to the server.


Regards,

Marin Bratanov
Telerik