HtmlTextWriter::TagKey Property
Gets or sets the HtmlTextWriterTag value for the specified markup element.
Assembly: System.Web (in System.Web.dll)
protected: property HtmlTextWriterTag TagKey { HtmlTextWriterTag get(); void set(HtmlTextWriterTag value); }
Property Value
Type: System.Web.UI::HtmlTextWriterTagThe markup element that is having its opening tag rendered.
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | The property value cannot be set. |
The TagKey property is of use only to classes that inherit from the HtmlTextWriter class. You should read or set the TagKey property only in a call to the RenderBeginTag method; this is the only time it is set to a consistent value.
The following code example demonstrates an overridden version of the RenderBeforeContent method in a class that derives from the HtmlTextWriter class. It uses the value of the TagKey property to determine whether a server control using the custom HtmlTextWriter object is rendering a <label> markup element. If it is, a <font> element with a color attribute set to red is returned to modify the formatting of the <label> element's text.
// Override the RenderBeforeContent method to write // a font element that applies red to the text in a Label element. virtual String^ RenderBeforeContent() override { // Check to determine whether the element being rendered // is a label element. If so, render the opening tag // of the font element; otherwise, call the base method. if ( TagKey == HtmlTextWriterTag::Label ) { return "<font color=\"red\">"; } else { return __super::RenderBeforeContent(); } }
Available since 1.1