HttpCacheVaryByParams.Item[String] 属性
定义
获取或设置一个值,该值指示缓存是否随指定的 HTTP 请求参数而变化。Gets or sets a value indicating whether the cache varies according to the specified HTTP request parameter.
public:
property bool default[System::String ^] { bool get(System::String ^ header); void set(System::String ^ header, bool value); };
public bool this[string header] { get; set; }
member this.Item(string) : bool with get, set
Default Public Property Item(header As String) As Boolean
参数
- header
- String
自定义参数的名称。The name of the custom parameter.
属性值
如果缓存应该随指定的参数值而变化,则为 true。true if the cache should vary by the specified parameter value.
例外
header 为 null。header is null.
示例
下面的代码示例演示如何 Item[] 从与关联的对象访问索引器 HttpCachePolicy HttpResponse 。The following code example demonstrates how the Item[] indexer is accessed from the HttpCachePolicy object associated with an HttpResponse.
Response.Cache.SetExpires(DateTime.Now.AddSeconds(60));
Response.Cache.SetCacheability(HttpCacheability.Public);
Response.Cache.SetValidUntilExpires(false);
Response.Cache.VaryByParams["Category"] = true;
if (Response.Cache.VaryByParams["Category"])
{
//...
}
Response.Cache.SetExpires(DateTime.Now.AddSeconds(60))
Response.Cache.SetCacheability(HttpCacheability.Public)
Response.Cache.SetValidUntilExpires(False)
Response.Cache.VaryByParams("Category") = True
If Response.Cache.VaryByParams("Category") Then
'...
End If
注解
当用作访问器 (getter) 时, Item[] true 如果在当前参数集合中找到指定参数的值,则索引器将返回; 如果将集合设置为根据 * (星号) (表示所有参数),则返回。When used as an accessor (getter), the Item[] indexer returns true if a value for the specified parameter is found in the current parameters collection, or if the collection is set to vary by * (an asterisk), which indicates all parameters.
当用作 (setter) 的赋值函数时, Item[] 索引器会将参数集合中对应于指定标头的参数的值设置为 true 。When used as a mutator (setter), the Item[] indexer sets the value for the parameter in the parameters collection that corresponds to the specified header to true. 可以指定值 * 来指示所有参数。The value * can be specified, which indicates all parameters.