📅 最后修改于: 2020-11-21 05:48:18 🧑 作者: Mango
AdRotator控件从列表中随机选择横幅图形，该列表在外部XML计划文件中指定。该外部XML计划文件称为广告文件。
AdRotator控件使您可以分别在AdvertisementFile和Target属性中指定广告文件和链接应遵循的窗口类型。
添加AdRotator的基本语法如下：
在详细介绍AdRotator控件及其属性之前，让我们研究一下广告文件的构造。
广告文件是XML文件，其中包含有关要显示的广告的信息。
可扩展标记语言(XML)是用于文本文档标记的W3C标准。它是基于文本的标记语言，使您可以使用有意义的标记以结构化格式存储数据。术语“可扩展”意味着您可以通过为应用程序定义有意义的标签来扩展描述文档的能力。
XML本身不是一种语言，就像HTML一样，而是一组用于创建新标记语言的规则。它是一种元标记语言。它允许开发人员创建用于特殊用途的自定义标签集。它构造，存储和传输信息。
以下是XML文件的示例：
Learn XML
Samuel Peterson
NSS Publications
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像所有XML文件一样，广告文件必须是结构化的文本文件，并带有定义良好的标签来描述数据。广告文件中通常使用以下标准XML元素：
| Element | Description |
|---|---|
| Advertisements | Encloses the advertisement file. |
| Ad | Delineates separate ad. |
| ImageUrl | The path of image that will be displayed. |
| NavigateUrl | The link that will be followed when the user clicks the ad. |
| AlternateText | The text that will be displayed instead of the picture if it cannot be displayed. |
| Keyword | Keyword identifying a group of advertisements. This is used for filtering. |
| Impressions | The number indicating how often an advertisement will appear. |
| Height | Height of the image to be displayed. |
| Width | Width of the image to be displayed. |
除这些标签外，还可以包含具有自定义属性的海关标签。以下代码说明了广告文件ads.xml：
rose1.jpg
http://www.1800flowers.com
Order flowers, roses, gifts and more
20
flowers
rose2.jpg
http://www.babybouquets.com.au
Order roses and flowers
20
gifts
rose3.jpg
http://www.flowers2moscow.com
Send flowers to Russia
20
russia
rose4.jpg
http://www.edibleblooms.com
Edible Blooms
20
gifts
AdRotator类派生自WebControl类，并继承其属性。除此之外，AdRotator类还具有以下属性：
| Properties | Description |
|---|---|
| AdvertisementFile | The path to the advertisement file. |
| AlternateTextFeild | The element name of the field where alternate text is provided. The default value is AlternateText. |
| DataMember | The name of the specific list of data to be bound when advertisement file is not used. |
| DataSource | Control from where it would retrieve data. |
| DataSourceID | Id of the control from where it would retrieve data. |
| Font | Specifies the font properties associated with the advertisement banner control. |
| ImageUrlField | The element name of the field where the URL for the image is provided. The default value is ImageUrl. |
| KeywordFilter | For displaying the keyword based ads only. |
| NavigateUrlField | The element name of the field where the URL to navigate to is provided. The default value is NavigateUrl. |
| Target | The browser window or frame that displays the content of the page linked. |
| UniqueID | Obtains the unique, hierarchically qualified identifier for the AdRotator control. |
以下是AdRotator类的重要事件：
| Events | Description |
|---|---|
| AdCreated | It is raised once per round trip to the server after creation of the control, but before the page is rendered |
| DataBinding | Occurs when the server control binds to a data source. |
| DataBound | Occurs after the server control binds to a data source. |
| Disposed | Occurs when a server control is released from memory, which is the last stage of the server control lifecycle when an ASP.NET page is requested |
| Init | Occurs when the server control is initialized, which is the first step in its lifecycle. |
| Load | Occurs when the server control is loaded into the Page object. |
| PreRender | Occurs after the Control object is loaded but prior to rendering. |
| Unload | Occurs when the server control is unloaded from memory. |
创建一个新网页并将AdRotator控件放在其上。
ads.xml文件和图像文件应位于网站的根目录中。
尝试执行上述应用程序，并观察到每次重新加载页面时，广告都会更改。