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HtmlTextWriter.GetAttributeKey(String) Method

  • Reference

Definition

Namespace:
System.Web.UI
Assembly:
System.Web.dll

Obtains the corresponding HtmlTextWriterAttribute enumeration value for the specified attribute.

protected:
 System::Web::UI::HtmlTextWriterAttribute GetAttributeKey(System::String ^ attrName);
protected System.Web.UI.HtmlTextWriterAttribute GetAttributeKey (string attrName);
member this.GetAttributeKey : string -> System.Web.UI.HtmlTextWriterAttribute
Protected Function GetAttributeKey (attrName As String) As HtmlTextWriterAttribute

Parameters

attrName
String

A string that contains the attribute for which to obtain the HtmlTextWriterAttribute.

Returns

HtmlTextWriterAttribute

The HtmlTextWriterAttribute enumeration value for the specified attribute; otherwise, an invalid HtmlTextWriterAttribute value if the attribute is not a member of the enumeration.

Examples

The following code example demonstrates how to use a class, derived from the HtmlTextWriter class, that overrides the RenderBeginTag method. The override checks whether tagKey is equal to the Font field, which indicates that a <font> markup element will be rendered. If so, the override calls the IsAttributeDefined method to find out whether the <font> element contains a Size attribute. If the IsAttributeDefined returns false, the AddAttribute method calls the GetAttributeKey method, which defines the Size and sets its value to 30pt.

// If the tagKey parameter is set to a <font> element
// but a size attribute is not defined on the element,
// the AddStyleAttribute method adds a size attribute
// and sets it to 30 point.
if ( tagKey == HtmlTextWriterTag::Font )
{
   if (  !IsAttributeDefined( HtmlTextWriterAttribute::Size ) )
   {
      AddAttribute( GetAttributeKey( "size" ), "30pt" );
   }
}

// If the tagKey parameter is set to a <font> element
// but a size attribute is not defined on the element,
// the AddStyleAttribute method adds a size attribute
// and sets it to 30 point. 
if (tagKey == HtmlTextWriterTag.Font)
{
    if (!IsAttributeDefined(HtmlTextWriterAttribute.Size))
    {
        AddAttribute(GetAttributeKey("size"), "30pt");
    }
}

' If the tagKey parameter is set to a <font> element
' but a size attribute is not defined on the element,
' the AddStyleAttribute method adds a size attribute
' and sets it to 30 point. 
If tagKey = HtmlTextWriterTag.Font Then
    If Not IsAttributeDefined(HtmlTextWriterAttribute.Size) Then
        AddAttribute(GetAttributeKey("size"), "30pt")
    End If
End If

Remarks

If attrName is null or an empty string (""), or cannot be found in the table of attribute names, the value -1, typed to an HtmlTextWriterAttribute object, is returned.

Applies to

See also