If I have an HtmlTextWriter with some content in it, is it possible to append the output of ontrol.RenderControl to the existing content of the HtmlTextWriter directly?
Or do I always have to output to a separate HtmlTextWriter/StringWriter/StringBuilder and then append the StringBuilder?
is it possible to get HtmlTextWriter of a control?
if no, then how can i call the RenderEndTag of a control in code behind?
i am facing a problem in my application. i extended the listbox user control and override its RenderEndTag event.
if i used the new listbox (Mylistbox) normally inside a WebPage, everything works fine. but when i put Mylistbox in a Webusercontrol and include the Webusercontrol in a WebPage, the RenderEndTag of the control is not called for some reason.
I am using TreeView Control in Asp.net. I have placed this control inside a panel. The tree control is completely binded (we don't want populate on demand) with an Xmldatasource during a callback and then I call Panel.renderControl to return the response (HTML) to the client side callback handler. Problem: 1. The tree expand/collapse (on click of plus sign) is causing postback whereas when I normally bind a tree with xml during postback and without using renderControl of container control, the expand/collapse (on click of plus sign) is being handled at client side. I want to stop this postback and allow tree node to call javascript to toggle nodes as it does when tree is binded and renderd in case of normal page life cycle.(when render control function is not used)
View 1 RepliesCan you use FluentHTML or other alternatives in an web application user control?
Can you put a markup file in a System.Web.UI.Control like the System.Web.UI.UserControl but without the burden of the Page object?
I would like to reduce the number of lines of the following code:
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I have read many posts in the past about TreeView in Custom CompositeControls and using RenderControl but have yet to see a solution. I declare a new Tree in the CreateChildControls method and in the render I try to call the RenderControls method and it gave me an object reference not set to instance of an object error. I have set the SkipLinkText to Nothing, String.Empty and "". Once I do that I get the second stack trace. The control worked when it was a control on the aspx page.
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STACK TRACE
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I am trying to find out what html is generated when a control is rendered. For most controls, the following worked fine: Dim tempbuilder As New System.Text.StringBuilder() Dim tempwriter As New
System.Web.UI.HtmlTextWriter(New System.IO.StringWriter(tempbuilder))
Dim generatedhtml as String Me.imgImage.RenderControl(tempwriter) generatedhtml = tempbuilder.ToString()
However, when I tried doing it with an ImageButton, I recieved the following error: Control 'ctl00_cphExampleContent_imgButton' of type 'ImageButton' must be placed inside a form tag with runat=server. What can I do to avoid this?
I am trying to add white-spacess before showing my hyperlink.
Data
{space} {space}HyperLink1
{space} {space}HyperLink1
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I need to get the html of a chart control built at runtime. When I call .RenderControl, I get System.NullReferenceException. What could the problem be? Is there another way to go about this (saving as image)? Below is my code.
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I have today developed a page that builds a series of RadioButtonLists, which may or may not be required fields.
As the page varies depending on DB values, I have rendered the controls using .RenderControl().
Unfortunatley I do not have the code to hand right now, but its along the lines of:
RadioButtonList rblQuestion = new RadioButtonList();
rblQuestion.id = question.ID;
// Add ListItems...
RequiredFieldValidator rfvQuestion = new RequiredFieldValidator();
rfvQuestion.ControlToValidate = rblQuestion.ID;
rfvQuestion.ErrorMessage = "*";
I then use .RenderControl on both rblQuestion and rfvQuestion, concatenate into a string then use the HTML String to populate a PlaceHolder.
This seems to work fine, all appears as expected apart from the RequiredFieldValidator - I get a red asterix (My ErrorMessage) next to each RadioButtonList - But this appears as soon as the page loads, not on a post/button click.
How would i go about loading a different control over an existing control?
By this i mean when i visit a page, a control is loaded into a PlaceHolder or Panel control, and then after i am finished with that UserControl, i want to clear it out and then load the next control in its place.
I have tried doing PlaceHolder.Controls.Clear but it still retains the first control and doesnt even add the next control to it at all.
The initial control is a data-entry control (Insert/Edit). Once the user does the data-entry (Insert for this question) needed, they click the Insert button, the data gets inserted into the database correctly then i want to pass control back to the parent page and have it load the next data-entry usercontrol in the place of the initial usercontrol.
I have tried doing it dynamically, with one placeholder control but that didnt seem to work. I tried doing it via a MultiView control with each of the data-entry usercontrols needed being pre-loaded into their own view and i couldnt get the Mutli-View to change activeindex.
Current Implementation:
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Former Implementation:
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I want to do a Jquery POST and get a chart using renderControl attribute of CHart which will return HTML attributes back to browser. The CHart is created dynamically based on parameters passed from post and from model. I have successfully done this on WEbforms,
However the same with MVC give a empty image. The handler doesn't perform the same in MVC2 3.5. I went near to 50 sites now.
I can't use other solution like base64encoding as IE6, 7 don't support it.
What I'm trying to do? I have few data parameteres to be sent (POST) to server and in response get the Chart image as tag along with other attributes and data appended in HTML form and sent to browser, all this to be done using JQUERY. No postbacks to be used.
I have badly searched on google, bing nothing turns out to be valuable.
I have this code that creates a document, and want to show it in a new page. I'm new with the HtmlTextWriter class, and don't know how to accomplish this.
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Quite simply I want to be able to test that a Asp.Net web forms server control is outputting the correct Html as it will be building dynamic content. I'm just starting to create the control and wanted to do it in a TDD style building up the Html that gets output. I've created a separate class to do the actual Html building so that I am able to test it in isolation outside of the normal Asp.Net pipeline.In my unit tests I can control what html is returned but I'm having problems confirming that the html contains the markup I am expecting for example:
<div id="wrapper">
<div id="fields">
</div>
[code]...
I am using the AttributeCollection with the HtmlTextWriter objects and want to set the ReadOnly attribute.
It seems everything needs to be setup Attribute="value" but the readonly property just needs the name not ReadOnly=True.
Is there a way to just output ReadOnly with the AttributeCollection instead of ReadOnly=True?
You may be asking why, I don't know how compatible ReadOnly=True would be with older browsers and everything I design is compatible with ie4+.
I have a third party tool that creates an img tag through code using HtmlTextWriter's RenderBeginTag, RenderEndTag & AddAttribute methods. I want to get the resulting HTML into a string.
I tried the reflection method mentioned here but I get a error "Unable to cast object of type 'System.Web.HttpWriter' to type 'System.IO.StringWriter". The InnerWriter type of the HtmlTextWriter is of type HttpWriter.
how to copy the output HTML into a string?
Addition: code from third party control
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I want to add the href attribute to a link element. This is my code:
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What went wrong and how can I fix this issue?
don't answer that I could assemble the string in some other way. I want to know how I can achieve this with the HtmlTextWriter
why asp.net does not render a dropdownlist with the autopostback property set to true when using the RenderControl method.
eg
Dim sw As New IO.StringWriter
Dim tw As New HtmlTextWriter(sw)
Dim table As New Table
[Code]...
my output renders the dropdown list without the onchange="javascript:setTimeout('__doPostBack(ddl1','')', 0)" that is generated by asp.net when using the dropdownlist normally.
I have a custom web part that I am trying to call the RenderContents method on, but the results only contains the surrounding div for the web part, and not any child controls.
Take for example this simple web part:
namespace MyWebParts
{
public class MyTestWebPart : WebPart
{
public MyTestWebPart()
{
this.CssClass = "myTestWebPart";
}
protected override void CreateChildControls()
{
base.CreateChildControls();
this.Controls.Add(new LiteralControl("Nothing here yet."));
}
}
}
Then, in an http handler, I'm trying to instantiate this web part and call its RenderControl method. The result is <div class="myTestWebPart"></div>.
Does anyone know why I am not getting my controls from CreateChildControls also added to the output?
Im using a web form that contains a button(having id=btnSubmit) dropdownlist(having id='ddlDynamic') and a panel which has a dynamicpopulateextender that makes use of the fllg webservice method
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I am creating a custom server control in which I place a RequiredFieldValidator. In the the Render method and I want to dynamically create a RequiredFieldValidator and render it to the HtmlTextWriter.
The problem is, when I call RenderControl on the RequiredFieldValidator, it only generates a span for me with no javascript or client side code.
How can I completely render a RequiredFieldValidator to an HtmlTextWriter?
I am using the following code to export a Gridview to an Excel spreadsheet. It works great until I select more than 10 records. At the 11th record I get an error on the line of code that reads....GridView1.RenderControl(hw)The error reads....RegisterForEventValidation can only be called during Render(); Description:An unhandled exception occurred during the execution of the current web request.Please review the stack trace for more information about the error and where it originated in the code.Exception Details: System.InvalidOperationException: RegisterForEventValidation can only be called during Render();Source Error:
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Sub:
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I am using a repeater control and i want to use one more repeater control inside the existing repeater control .
Like this:
<asp:Repeater ID="Repeater1" runat="server"> <HeaderTemplate> </HeaderTemplate>
<ItemTemplate>
<!-- start child repeater --> Here I want to use one repater control <!-- end child repeater -->
</ItemTemplate>
</asp:Repeater>
I've got an existing asp.net project written in vb.net. Another person has written a user control in c#.
the steps for adding that C# user control to the vb.net app?
I've tried copying them to the folder and using "Add existing item", however it doesn't compile the code behind at all.
I am creating a custom control and had a thought before I began. My control relies on the jQuery library to work. What if the user already has a version of the library already on their page. Will this effect anything? If my version is newer / older and my control will only work with that version of the libaray, what should I do?
View 1 RepliesI hv a file upload control which save files in folder upload_html. When I upload file of same name which already exists upload_html folder it does't replace that file.........
I want that file to be replaced from that folder.............