Prevent wrapping <span> tags for ASP.NET server control

Question

I am writing various ASP.NET Server controls and am needing to remove the tags that wrap my control by default. I am aware that you can change the tag to a different tag (as in this question, How Do I Change the render behavior of my custom control from being a span) but how can you prevent it?

I am inheriting from WebControl (can also inherit from CompositeControl).

I typically get:

<span>Control output</span>

I need:

Control output

I am overriding RenderContents(HtmlTextWriter output) and the CreateChildControls() methods (across various controls). My immediate need is to address the issue using the RenderContents(HtmlTextWriter output) method.

Lymn

Answer 1

What about this?

    public override void RenderBeginTag(HtmlTextWriter writer)
    {
        writer.Write("");
    }

    public override void RenderEndTag(HtmlTextWriter writer)
    {
        writer.Write("");
    }

Dibbuk

Brilliant solution :) I actually used an empty method for both and just put a comment line explaining why they are there. Not sure if that is any different than yours but having it write a blank string seems unnecessary. – Ingrowing

This helped me a lot - had to read a lot of 'good tips', before I found your perfect solution. Would give you more than one upvote if possible g – Laevo

I'm trying to remove the span surrounding a System.Web.UI.Web.Controls.Checkbox. This works if I inherit from that class, however, the CssClass value doesn't get applied to the rendered CheckBox control. How would I do that? – Struble

Answer 2

A more elegant way to do this is by using the contrustor of WebControl (By default this is called with the HtmlTextWriterTag.Span)

public MyWebControl() : base(HtmlTextWriterTag.Div){}

and override the RenderBeginTag method to add custom attributes or other stuff:

public override void RenderBeginTag(HtmlTextWriter writer)
    {
        writer.AddAttribute("class", "SomeClassName");
        base.RenderBeginTag(writer);
    }

Hatteras

This doesn't solve the problem. While this will allow you to change the span to a different element, such as the div given in your example, it doesn't allow you to remove the outer element completely, as requested. You could pass in HtmlTextWriterTag.Unknown or an empty string to the call to base(), but while that removes the name of the element, the angle brackets for the element are still kept, so you end up with the invalid markup: <>. – Coley

Answer 3

I was experiencing the same issue. In my case I was overriding the methods:

protected override void OnPreRender(EventArgs e)
    { /* Insert the control's stylesheet on the page */ }

and

protected override void RenderContents(HtmlTextWriter output)
        { /* Control rendering here, <span> tag will show up */ }

To prevent this, I simply replaced the RenderContents override with the following:

protected override void Render(HtmlTextWriter output)
        { /* Control rendering, no <span> tag */ }

Hope this helps.

Local

Using Render instead of RenderContents works for me. This way the RenderBeginTag/RenderEndTag is never actually called – Edinburgh

Answer 4

I don't think the accepted answer is entirely necessary. I could be wrong, but the render method calls all three:

• RenderBeginTag
• RenderContents
• RenderEndTag

So you should be able to just override render and manually call RenderContents:

protected override void Render(HtmlTextWriter writer)
{ 
    this.RenderContents(writer);
}

Anyone? Maybe I'm missing something. I know this thread is old but I ran into this recently that the above was my solution.

Factor