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HtmlTextWriter.OnStyleAttributeRender Method

  • Reference

Definition

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

Determines whether the specified markup style attribute and its value can be rendered to the current markup element.

protected:
 virtual bool OnStyleAttributeRender(System::String ^ name, System::String ^ value, System::Web::UI::HtmlTextWriterStyle key);
protected virtual bool OnStyleAttributeRender (string name, string value, System.Web.UI.HtmlTextWriterStyle key);
abstract member OnStyleAttributeRender : string * string * System.Web.UI.HtmlTextWriterStyle -> bool
override this.OnStyleAttributeRender : string * string * System.Web.UI.HtmlTextWriterStyle -> bool
Protected Overridable Function OnStyleAttributeRender (name As String, value As String, key As HtmlTextWriterStyle) As Boolean

Parameters

name
String

A string containing the name of the style attribute to render.

value
String

A string containing the value that is assigned to the style attribute.

key
HtmlTextWriterStyle

The HtmlTextWriterStyle associated with the style attribute.

Returns

Boolean

Always true.

Examples

The following code example shows how to override the OnStyleAttributeRender method. If a Color style attribute is rendered, but the Color value is not purple, the OnStyleAttributeRender override uses the AddStyleAttribute method to set the Color attribute to purple.

// If a color style attribute is to be rendered,
// compare its value to purple. If it is not set to
// purple, add the style attribute and set the value
// to purple, then return false.
protected override bool OnStyleAttributeRender(string name,
    string value,
    HtmlTextWriterStyle key)
{

    if (key == HtmlTextWriterStyle.Color)
    {
        if (string.Compare(value, "purple") != 0)
        {
            AddStyleAttribute("color", "purple");
            return false;
        }
    }

    // If the style attribute is not a color attribute,
    // use the base functionality of the
    // OnStyleAttributeRender method.
    return base.OnStyleAttributeRender(name, value, key);
}

' If a color style attribute is to be rendered,
' compare its value to purple. If it is not set to
' purple, add the style attribute and set the value
' to purple, then return false.
Protected Overrides Function OnStyleAttributeRender(name As String, _
    value As String, _
    key As HtmlTextWriterStyle) _
As Boolean

    If key = HtmlTextWriterStyle.Color Then
        If [String].Compare(value, "purple") <> 0 Then
            AddStyleAttribute("color", "purple")
            Return False
        End If
    End If

    ' If the style attribute is not a color attribute,
    ' use the base functionality of the
    ' OnStyleAttributeRender method.
    Return MyBase.OnStyleAttributeRender(name, value, key)
End Function 'OnStyleAttributeRender

Remarks

The HtmlTextWriter class implementation of the OnStyleAttributeRender method always returns true. The OnStyleAttributeRender overrides can determine whether a style attribute will be rendered to the page.

Notes to Inheritors

If you inherit from the HtmlTextWriter class, you can override the OnStyleAttributeRender(String, String, HtmlTextWriterStyle) method to return false to prevent a style attribute from being rendered at all, being rendered on a particular element, or being rendered for a particular markup language. For example, if you do not want the object that is derived from HtmlTextWriter to render the color style attribute to a <p> element, you can override the OnStyleAttributeRender(String, String, HtmlTextWriterStyle) and return false when name passes color and the TagName property value is p.

Applies to

See also