blazor wasm-托管+ gRCP Web（流）

Question

是否可以通过gRCP Web（http / 1.1）进行cleint服务器流式响应？

我有一个可以正常工作的客户端/服务器+数据库解决方案，但似乎我必须等待服务器的完整响应（请参阅服务器中的//await Task.Delay(2000);）

我想发生的是，客户端应该在发送回客户端的每个“服务器标记”上进行渲染，而不是等待流关闭并呈现完整的响应。

有任何想法吗？

协议

syntax = "proto3";
option csharp_namespace = "GrpcReports";
package reports;

service Reports {
  rpc AllReports (ReportRequest) returns (stream ReportReply);
}

message ReportRequest {}
message ReportReply {
   string name = 1;
}

服务器

// server
public class ReportsService : Reports.ReportsBase
{
        private readonly IReportRepository _repository;
        private readonly IMapper _mapper;

        public ReportsService(IReportRepository repository, IMapper mapper)
        {
            _repository = repository ?? throw new ArgumentNullException(nameof(IReportRepository));
            _mapper = mapper ?? throw new ArgumentNullException(nameof(IMapper));
        }

        public override async Task AllReports(ReportRequest request, IServerStreamWriter<ReportReply> responseStream, ServerCallContext context)
        {
            foreach (var item in _mapper.Map<List<ReportReply>>(await _repository.GetAllReportsAsync()))
            {
                Log.Information("{@ReportReply}", item);
                await responseStream.WriteAsync(item);
                //await Task.Delay(2000);
            }
        }
}

客户

@page "/"
@using Grpc.Core
@using GrpcReports
@using AutoMapper
@inject Reports.ReportsClient _reportsClient
@inject IMapper _mapper

<h1>Invoke gRPC service</h1>

<button @onclick="AllReports" class="btn btn-primary">Call gRPC service</button>
<p>Server report response from database:</p>

<ul>
    @foreach (var item in reportReplys)
    {
        <li>@item.Name</li>
    }
</ul>

@code {
    List<ReportReply> reportReplys = new List<ReportReply>();

    async Task AllReports()
    {
        using (var call = _reportsClient.AllReports(new ReportRequest()))
        {
            while (await call.ResponseStream.MoveNext())
            {
                reportReplys.Add(call?.ResponseStream?.Current);
            }
        }
    }
}

Answer 1

因此gRPC Web流确实可以正常工作，我唯一需要添加的就是在每个服务器刻度上重新呈现UI。

您唯一需要添加到代码中的是StateHasChanged();。

客户端侧更新：

while (await call?.ResponseStream?.MoveNext())
{
    reportReplys.Add(call?.ResponseStream?.Current);
    StateHasChanged();
}

参考：https://docs.microsoft.com/en-us/aspnet/core/blazor/components/lifecycle?view=aspnetcore-3.1#state-changes