Setting Version and VersionPolicy header on httpRequests

[SangeethaJanakiraman]

By default, the http version used by Google is HTTP 1.1 ( I checked it by printing the response.Version) .
I have tried to set the version to 2.0 (as it has many advantages)

I was able to do it for Download request as below

var req = service.Files.Get(file.fileId);
req.ModifyRequest = AddHeader; //I set the Version and VersionPolicy on this callback.
var progress = await req.ExecuteAsStreamAsync DownloadAsync(fs);

But for batch request, if I set it on individual request, it is not getting honored.

BatchRequest _batch = new BatchRequest(service);
foreach (var file in files)
{
        var request = service.Files.Get(file.fileId);
        request.ModifyRequest = AddHeader;
        request.Fields = "*";
        _batch.Queue(request, response);
 }

Setting it on HttpClient level also doesnt seem to get honored.

var service = new DriveService(new BaseClientService.Initializer()
 {
     HttpClientFactory = GetHttpClientFactory(),
     HttpClientInitializer = ImpersonatedServiceCredential,
 });
 service.HttpClient.DefaultRequestVersion = new Version(2, 0); // Use HTTP/2
 service.HttpClient.DefaultVersionPolicy = HttpVersionPolicy.RequestVersionOrHigher;

Can you suggest how can I set the request version to 2.0 for all my requests ?

[amanda-tarafa]

Modifying the individual requests in a batch won't work because the batch is sent as a single request containing the individual requests. We currently don't support modifying the batch request.

From Microsoft's documentation for HttpClient.DefaultRequestVersion (and similarly for HttpClient.DefaultVersionPolicy):

The DefaultRequestVersion property doesn't apply to the SendAsync method. The HttpRequestMessage parameter passed as the argument to the SendAsync method has its own Version property that controls the HTTP version used for the request.

Internally, we build the HttpRequestMessage (because requests are more complext than what we can achieve whith the HTTP verb specific methods) and we use SendAsync to make the request, so those properties aren't apply.

I'll mark this as a feature request and think about what's the best way to support it.