How do I create a valueless Attribute on HtmlGenericControl

Question

I am creating a new HtmlGenericControl in C#/ASP.net and need to create an attribute on the control with no value. This means no ="" after the attribute.

oHtmlGenericControl = new HtmlGenericControl("MyHtmlTag");
oHtmlGenericControl.Attributes.Add("MyFirstAttribute", "MyAttributeValue");
oHtmlGenericControl.Attributes.Add("MySecondAttribute", "");

Will produce something like this...

<MyHtmlTag MyFirstAttribute="MyAttributeValue" MySecondAttribute=""></MyHtmlTag >

And what I want is this...

<MyHtmlTag MyFirstAttribute="MyAttributeValue" MySecondAttribute></MyHtmlTag >

I've tried passing null instead of an emptry string but then the attribute does not appear at all.

I did the following thinking it was working at first...

oHtmlGenericControl = new HtmlGenericControl("MyHtmlTag");
oHtmlGenericControl.TagName = oHtmlGenericControl.TagName + " MySecondAttribute";

But it ended up giving me this...

<MyHtmlTag MySecondAttribute></MyHtmlTag MySecondAttribute>

So, according to the comments, there may not be any "valueless" attributes in HTML. On closer inspection of the W3C standard the proper way to add the attribute I needed to add was AttributeName="AttributeName". The AttributeName by itself is accepted and considered valid by most browsers though and given without a value in most online examples.

oHtmlGenericControl.Attributes.Add("MyAttributeName", "MyAttributeName");

So the above example will work in my case (and possibly all similar cases), but doesn't exactly answer the question on if it is possible to add an attribute without a value using the HtmlGenericControl.

<MyHtmlTag MyAttributeName="MyAttributeName"></MyHtmlTag>

Answer 1

First, investigate why you need an empty attribute. Maybe you have a valid reason, if so try this (untested):

var wr = new System.IO.StringWriter(new StringBuilder("MySecondAttribute"));
var htw = new HtmlTextWriter(wr);
oHtmlGenericControl.Attributes.AddAttributes(htw);