System.Net.Http.HttpClient缓存

Question

Is there a way to set up cache for HttpClient ? I would like to get the HttpClient response (which is reaching my endpoint with get method), but if there is no internet connection on the client device, I would like to return the last response for this specific call. If there is a internet connection, the HttpClient get the response (normal behavior) and update the cache by this new response for this call.

Any idea to set up this behavior in a cross plateform Xamarin Forms project ?

Answer 1

You may find useful any of these Akavache methods:

// Attempt to return an object from the cache. If the item doesn't
// exist or returns an error, call a Func to return the latest
// version of an object and insert the result in the cache.
IObservable<T> GetOrFetchObject<T>(string key, Func<Task<T>> fetchFunc, DateTimeOffset? absoluteExpiration = null);

// Like GetOrFetchObject, but isn't async
IObservable<T> GetOrCreateObject<T>(string key, Func<T> fetchFunc, DateTimeOffset? absoluteExpiration = null);

// Immediately return a cached version of an object if available, but *always*
// also execute fetchFunc to retrieve the latest version of an object.
IObservable<T> GetAndFetchLatest<T>(string key,
    Func<Task<T>> fetchFunc,
    Func<DateTimeOffset, bool> fetchPredicate = null,
    DateTimeOffset? absoluteExpiration = null);