Do HttpClient and HttpClientHandler have to be disposed between requests?

Question

System.Net.Http.HttpClient and System.Net.Http.HttpClientHandler in .NET Framework 4.5 implement IDisposable (via System.Net.Http.HttpMessageInvoker).

The usin

Answer 1

In typical usage (responses<2GB) it is not necessary to Dispose the HttpResponseMessages.

The return types of the HttpClient methods should be Disposed if their Stream Content is not fully Read. Otherwise there is no way for the CLR to know those Streams can be closed until they are garbage collected.

• If you are reading the data into a byte[] (e.g. GetByteArrayAsync) or string, all data is read, so there is no need to dispose.
• The other overloads will default to reading the Stream up to 2GB (HttpCompletionOption is ResponseContentRead, HttpClient.MaxResponseContentBufferSize default is 2GB)

If you set the HttpCompletionOption to ResponseHeadersRead or the response is larger than 2GB, you should clean up. This can be done by calling Dispose on the HttpResponseMessage or by calling Dispose/Close on the Stream obtained from the HttpResonseMessage Content or by reading the content completely.

Whether you call Dispose on the HttpClient depends on whether you want to cancel pending requests or not.