HtmlTextWriter.AddAttribute Method (String, String)
Assembly: System.Web (in system.web.dll)
Use the AddAttribute overload of the AddAttribute(String,String) method if the attribute is not one of the HtmlTextWriterAttribute values, or if the attribute is not known until run time.
For an instance of any given markup element, the HtmlTextWriter class maintains a list of attributes for that element. When the RenderBeginTag method is called, any attributes added by the AddAttribute method are rendered to the opening tag of the element. The list of attributes is then cleared from the HtmlTextWriter object.
The coding pattern for rendering markup elements is as follows:
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Use the AddAttribute method to add any attributes to the element.
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Use the RenderBeginTag method.
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Use other methods as needed to render the content found between the element's opening and closing tags.
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Use the RenderEndTag method.
The following code example demonstrates how to call the AddAttribute method before calling the RenderBeginTag method. The code calls two different overloads of AddAttribute and two different overloads of AddStyleAttribute before it calls the RenderBeginTag method to render a <span> element to the output stream. The AddAttribute(String,String) method is used to define the custom attribute named CustomAttribute and the custom value named CustomAttributeValue for the <span> element that this code renders.