HtmlTextWriter.IsStyleAttributeDefined Method (HtmlTextWriterStyle)

Determines whether the specified markup style attribute is rendered during the next call to the RenderBeginTag method.

Namespace: System.Web.UI
Assembly: System.Web (in system.web.dll)

protected:
bool IsStyleAttributeDefined (
	HtmlTextWriterStyle key
)
protected boolean IsStyleAttributeDefined (
	HtmlTextWriterStyle key
)
protected function IsStyleAttributeDefined (
	key : HtmlTextWriterStyle
) : boolean
Not applicable.

Parameters

key

The HtmlTextWriterStyle associated with the attribute.

Return Value

true if the attribute will be rendered during the next call to the RenderBeginTag method; otherwise, false.

To get the value that will be rendered with the specified style attribute, use the IsStyleAttributeDefined(HtmlTextWriterStyle,String) overload of the IsStyleAttributeDefined method.

The following code example shows how to check whether a <label> element is being rendered. If so, the IsStyleAttributeDefined method checks whether a Color style attribute has been defined on the element. If the Color attribute has not been defined, the AddStyleAttribute method defines the Color attribute and sets its value to red.

// If the markup element being rendered is a Label,
// render the opening tag of a <Font> element before it.
if ( tagKey == HtmlTextWriterTag::Label )
{
   
   // Check whether a Color style attribute is
   // included on the Label. If not, use the
   // AddStyleAttribute and GetStyleName methods to add one
   // and set its value to red.
   if (  !IsStyleAttributeDefined( HtmlTextWriterStyle::Color ) )
   {
      AddStyleAttribute( GetStyleName( HtmlTextWriterStyle::Color ), "red" );
   }


// If the markup element being rendered is a Label,
// render the opening tag of a Font element before it.
if (tagKey.Equals(HtmlTextWriterTag.Label)) {
    // Check whether a Color style attribute is 
    // included on the Label. If not, use the
    // AddStyleAttribute and GetStyleName methods to add one
    // and set its value to red.
    if (!(IsStyleAttributeDefined(HtmlTextWriterStyle.Color))) {
        AddStyleAttribute(GetStyleName(HtmlTextWriterStyle.Color), 
            "red");
    }

Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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