HttpCacheDirectiveHeaderValueCollection class

Applies to Windows and Windows Phone

Represents the value of the Cache-Control HTTP header on HTTP content associated with an HTTP request or response.

Syntax


var httpCacheDirectiveHeaderValueCollection = cacheControl;

Attributes

[DualApiPartition()]
[MarshalingBehavior(Agile)]
[Threading(Both)]
[Version(0x06030000)]

Members

The HttpCacheDirectiveHeaderValueCollection class has these types of members:

Methods

The HttpCacheDirectiveHeaderValueCollection class has these methods. With C#, Visual Basic, and C++, it also inherits methods from the Object class.

MethodDescription
Add [C#, VB]Adds a new item to the end of the collection.
Append [C++, JavaScript]Adds a new HttpNameValueHeaderValue item to the end of the collection.
Clear Removes all objects from the collection.
Contains [C#, VB]Determines whether an element is in the collection.
CopyTo [C#, VB]Copies the elements of the collection to an array, starting at a particular array index in the destination array.
First [C++, JavaScript]Retrieves an iterator to the first HttpNameValueHeaderValue item in the collection.
GetAt [C++, JavaScript]Returns the HttpNameValueHeaderValue at the specified index in the collection.
GetMany [C++, JavaScript]Retrieves the HttpNameValueHeaderValue items that start at the specified index in the collection.
GetView [C++, JavaScript]Returns an immutable view of the HttpCacheDirectiveHeaderValueCollection.
IndexOf [C++, JavaScript]Retrieves the index of an HttpNameValueHeaderValue in the collection.
IndexOf [C#, VB]Determines the index of a specific item in the collection.
Insert [C#, VB]Inserts an item into the collection at the specified index.
InsertAt [C++, JavaScript]Inserts an HttpNameValueHeaderValue into the collection at the specified index.
ParseAdd Parses and adds an entry to the HttpCacheDirectiveHeaderValueCollection.
Remove [C#, VB]Removes a specific object from the collection.
RemoveAt [C++, JavaScript]Removes the entry at the specified index from the HttpCacheDirectiveHeaderValueCollection.
RemoveAt [C#, VB]Removes the element at the specified index of the collection.
RemoveAtEnd [C++, JavaScript]Removes the last HttpNameValueHeaderValue item from the collection.
ReplaceAll [C++, JavaScript]Replaces all the HttpNameValueHeaderValue items in the collection with the specified HttpNameValueHeaderValue items.
SetAt [C++, JavaScript]Sets the HttpNameValueHeaderValue at the specified index in the collection.
ToString Returns a string that represents the current HttpCacheDirectiveHeaderValueCollection object.
TryParseAdd Tries to parse and add the specified item to the HttpCacheDirectiveHeaderValueCollection.

 

Properties

The HttpCacheDirectiveHeaderValueCollection class has these properties.

PropertyAccess typeDescription

Count [C#, VB]

Read-onlyGets the number of elements that are contained in the collection.

IsReadOnly [C#, VB]

Read-onlyGets a value indicating whether the collection is read-only.

Item [C#, VB]

Read/writeGets or sets the element at the specified index.

MaxAge

Read/writeGets or sets the value of the max-age directive in the Cache-Control HTTP header.

MaxStale

Read/writeGets or sets the value of the max-stale directive in the Cache-Control HTTP header.

MinFresh

Read/writeGets or sets the value of the min-fresh directive in the Cache-Control HTTP header.

SharedMaxAge

Read/writeGets or sets the value of the s-maxage directive in the Cache-Control HTTP header.

Size [C++, JavaScript]

Read-onlyGets the number of HttpNameValueHeaderValue objects in the collection.

 

Remarks

The HttpCacheDirectiveHeaderValueCollection class represents the value of the Cache-Control HTTP header on HTTP content associated with an HTTP request or an HTTP response.

The CacheControl property on the HttpRequestHeaderCollection returns an HttpCacheDirectiveHeaderValueCollection. The CacheControl property on the HttpResponseHeaderCollection returns an HttpCacheDirectiveHeaderValueCollection.

Collection member lists

For JavaScript, HttpCacheDirectiveHeaderValueCollection has the members shown in the member lists. In addition, HttpCacheDirectiveHeaderValueCollection supports members of Array.prototype and using an index to access items.

Enumerating the collection in C# or Microsoft Visual Basic

You can iterate through an HttpCacheDirectiveHeaderValueCollection object in C# or Microsoft Visual Basic. In many cases, such as using foreach syntax, the compiler does this casting for you and you won't need to cast to IEnumerable<HttpNameValueHeaderValue> explicitly. If you do need to cast explicitly, for example if you want to call GetEnumerator, cast the collection object to IEnumerable<T> with an HttpNameValueHeaderValue constraint.

Examples

The following sample code shows a method to get and set the Cache-Control HTTP header on an HttpRequestMessage object using the properties and methods on the HttpCacheDirectiveHeaderValueCollection class.


using System;
using Windows.Web.Http;
using Windows.Web.Http.Headers;

        public void DemonstrateHeaderRequestCacheControl() {
            var request = new HttpRequestMessage();
            bool parsedOk = false;

            // Set the header with a string.
            parsedOk = request.Headers.CacheControl.TryParseAdd("no-store");

            // Set the header with a strong type.
            request.Headers.CacheControl.Add(new HttpNameValueHeaderValue("max-age", "10"));

            // Get the strong type out
            foreach (var value in request.Headers.CacheControl) {
                System.Diagnostics.Debug.WriteLine("One of the CacheControl values: {0}={1}", value.Name, value.Value);
            }

            // The ToString() is useful for diagnostics, too.
            System.Diagnostics.Debug.WriteLine("The CacheControl ToString() results: {0}", request.Headers.CacheControl.ToString());
        }


The following sample code shows a method to get and set the Cache-Control HTTP header on an HttpResponseMessage object using the properties and methods on the HttpCacheDirectiveHeaderValueCollection class.


using System;
using Windows.Web.Http;
using Windows.Web.Http.Headers;

        public void DemonstrateHeaderResponseCacheControl() {
            var response = new HttpResponseMessage();

            // Set the header with a string
            response.Headers.CacheControl.TryParseAdd("public");

            // Set the header with a strong type
            response.Headers.CacheControl.Add(new HttpNameValueHeaderValue("max-age", "30"));

            // Get the strong type out
            foreach (var value in response.Headers.CacheControl) {
                System.Diagnostics.Debug.WriteLine("CacheControl {0}={1}", value.Name, value.Value);
            }

            // The ToString() is useful for diagnostics, too.
            System.Diagnostics.Debug.WriteLine("The CacheControl ToString() results: {0}", response.Headers.CacheControl.ToString());
        }


Requirements

Minimum supported client

Windows 8.1 [Windows Store apps, desktop apps]

Minimum supported server

Windows Server 2012 R2 [Windows Store apps, desktop apps]

Minimum supported phone

Windows Phone 8.1 [Windows Phone Silverlight 8.1 and Windows Runtime apps]

Namespace

Windows.Web.Http.Headers
Windows::Web::Http::Headers [C++]

Metadata

Windows.winmd

See also

HttpResponseHeaderCollection
HttpResponseHeaderCollection.CacheControl
HttpRequestHeaderCollection
HttpRequestHeaderCollection.CacheControl
HttpResponseMessage
IIterable(HttpNameValueHeaderValue)
IStringable
IVector(HttpNameValueHeaderValue)
Object

 

 

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