c# - System.Net.Http.HttpClient缓存

Question

有没有办法为 HttpClient 设置缓存？ 我想获得 HttpClient 响应(通过 get 方法到达我的端点)，但如果客户端设备上没有互联网连接，我想返回此特定调用的最后响应。如果有 Internet 连接，HttpClient 会获取响应(正常行为)并通过此调用的新响应更新缓存。

想在跨平台 Xamarin Forms 项目中设置此行为吗？

Answer 1

您可能会发现其中任何一个有用 Akavache方法:

// 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);