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HtmlTextWriter.GetAttributeKey Method

Obtains the corresponding HtmlTextWriterAttribute enumeration value for the specified attribute.

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

protected HtmlTextWriterAttribute GetAttributeKey(
	string attrName
)

Parameters

attrName
Type: System.String

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

Return Value

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

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.

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");
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1
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