重试HttpClient不成功的请求

重试HttpClient不成功的请求

代替实施包裹该重试功能的

HttpClient

，可以考虑构成

HttpClient

与

HttpMessageHandler

内部执行所述重试逻辑。例如：

public class RetryHandler : DelegatingHandler{    // Strongly consider limiting the number of retries - "retry forever" is    // probably not the most user friendly way you could respond to "the    // network cable got pulled out."    private const int MaxRetries = 3;    public RetryHandler(HttpMessageHandler innerHandler)        : base(innerHandler)    { }    protected override async Task<HttpResponseMessage> SendAsync(        HttpRequestMessage request,        CancellationToken cancellationToken)    {        HttpResponseMessage response = null;        for (int i = 0; i < MaxRetries; i++)        { response = await base.SendAsync(request, cancellationToken); if (response.IsSuccessStatusCode) {     return response; }        }        return response;    }}public class BusinessLogic{    public void FetchSomeThingsSynchronously()    {        // ...        // Consider abstracting this construction to a factory or IoC container        using (var client = new HttpClient(new RetryHandler(new HttpClientHandler())))        { myResult = client.PostAsync(yourUri, yourHttpContent).Result;        }        // ...    }}