HtmlTextWriter.GetStyleKey(String) 方法

定义

获取指定样式的 HtmlTextWriterStyle 枚举值。Obtains the HtmlTextWriterStyle enumeration value for the specified style.

protected:
 System::Web::UI::HtmlTextWriterStyle GetStyleKey(System::String ^ styleName);
protected System.Web.UI.HtmlTextWriterStyle GetStyleKey (string styleName);
member this.GetStyleKey : string -> System.Web.UI.HtmlTextWriterStyle
Protected Function GetStyleKey (styleName As String) As HtmlTextWriterStyle

参数

styleName
String

要为其获取 HtmlTextWriterStyle 的样式属性。The style attribute for which to obtain the HtmlTextWriterStyle.

返回

styleName 相对应的 HtmlTextWriterStyle 枚举值。The HtmlTextWriterStyle enumeration value corresponding to styleName.

示例

下面的代码示例演示如何重写从 HtmlTextWriter 类派生的类中的 RenderBeginTag 方法。The following code example demonstrates how to override the RenderBeginTag method in a class derived from the HtmlTextWriter class. RenderBeginTag 重写确定是否将呈现 <label> 标记,如果是,则检查元素中是否存在 Color 特性。The RenderBeginTag override determines whether a <label> markup will be rendered, and, if so, checks the element for a Color attribute. 如果尚未定义 Color 属性,GetStyleKey 方法将用作对 AddStyleAttribute 方法的调用中的第一个参数,以将 Color 特性添加到 <label> 标记元素,并将 Color 特性设置为 redIf a Color attribute has not been defined, the GetStyleKey method is used as the first parameter in a call to the AddStyleAttribute method to add a Color attribute to a <label> markup element and set the Color attribute to red.

// Override the RenderBeginTag method to check whether
// the tagKey parameter is set to a <label> element
// or a <font> element.   
virtual void RenderBeginTag( HtmlTextWriterTag tagKey ) override
{
   // If the tagKey parameter is set to a <label> element
   // but a color attribute is not defined on the element,
   // the AddStyleAttribute method adds a color attribute
   // and sets it to red.
   if ( tagKey == HtmlTextWriterTag::Label )
   {
      if (  !IsStyleAttributeDefined( HtmlTextWriterStyle::Color ) )
      {
         AddStyleAttribute( GetStyleKey( "color" ), "red" );
      }
   }

   // 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" );
      }
   }

   // Call the base class's RenderBeginTag method
   // to ensure that calling this custom markup writer
   // includes functionality for all other elements.
   __super::RenderBeginTag( tagKey );
}
// Override the RenderBeginTag method to check whether
// the tagKey parameter is set to a <label> element
// or a <font> element.
public override void RenderBeginTag(HtmlTextWriterTag tagKey)
{

    // If the tagKey parameter is set to a <label> element
    // but a color attribute is not defined on the element,
    // the AddStyleAttribute method adds a color attribute
    // and sets it to red.
    if (tagKey == HtmlTextWriterTag.Label)
    {
        if (!IsStyleAttributeDefined(HtmlTextWriterStyle.Color))
        {
            AddStyleAttribute(GetStyleKey("color"), "red");
        }
    }
    // 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");
        }
    }
    // Call the base class's RenderBeginTag method
    // to ensure that this custom MarkupTextWriter
    // includes functionality for all other markup elements.
    base.RenderBeginTag(tagKey);
}
' Override the RenderBeginTag method to check whether
' the tagKey parameter is set to a <label> element
' or a <font> element.   
Public Overloads Overrides Sub RenderBeginTag(ByVal tagKey As HtmlTextWriterTag)
    ' If the tagKey parameter is set to a <label> element
    ' but a color attribute is not defined on the element,
    ' the AddStyleAttribute method adds a color attribute
    ' and sets it to red.
    If tagKey = HtmlTextWriterTag.Label Then
        If Not IsStyleAttributeDefined(HtmlTextWriterStyle.Color) Then
            AddStyleAttribute(GetStyleKey("color"), "red")
        End If
    End If

    ' 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

    ' Call the base class's RenderBeginTag method
    ' to ensure that this custom MarkupTextWriter
    ' includes functionality for all other markup elements.
    MyBase.RenderBeginTag(tagKey)
End Sub

注解

如果 styleName 与任何 HtmlTextWriterStyle 枚举值均不对应,则 GetStyleKey 方法返回类型为 HtmlTextWriterStyle 值的值1。The GetStyleKey method returns the value -1 typed as a HtmlTextWriterStyle value, if styleName does not correspond to any HtmlTextWriterStyle enumeration value.

适用于

另请参阅