angular - 无法使用 Angular 5 客户端启动与信号器核心中心的连接

Question

我有一个运行 SignalR Core 集线器的 .Net Core 2.0 C# Web Api。我什至无法从收到此错误的 Angular (5.0.1) 启动 () 我的 hubConnection:

OPTIONS https://localhost:44301/hubs/sample 405 (Method Not Allowed)

Error: Failed to start the connection. Error: Method Not Allowed

Error while establishing connection :(

XHR failed loading: OPTIONS "https://localhost:44301/hubs/sample".

HttpError: Method Not Allowed at XMLHttpRequest.xhr.onload [as __zone_symbol__ON_PROPERTYload] (webpack-internal:///../../../../@aspnet/signalr-client/dist/src/HttpClient.js:30:28) at XMLHttpRequest.wrapFn (webpack-internal:///../../../../zone.js/dist/zone.js:1166:39) at ZoneDelegate.invokeTask (webpack-internal:///../../../../zone.js/dist/zone.js:425:31) at Object.onInvokeTask (webpack-internal:///../../../core/esm5/core.js:4816:33) at ZoneDelegate.invokeTask (webpack-internal:///../../../../zone.js/dist/zone.js:424:36) at Zone.runTask (webpack-internal:///../../../../zone.js/dist/zone.js:192:47) at ZoneTask.invokeTask [as invoke] (webpack-internal:///../../../../zone.js/dist/zone.js:499:34) at invokeTask (webpack-internal:///../../../../zone.js/dist/zone.js:1540:14) at XMLHttpRequest.globalZoneAwareCallback (webpack-internal:///../../../../zone.js/dist/zone.js:1566:17)

我什至都在努力调试这个问题，即使在 fiddler 的帮助下我也无法解决它。它似乎不是我的 Api 的问题，因为 Kestrel 控制台打印出对集线器的请求进来了，但没有打印出任何错误。而且我能够毫无问题地获取、放置和发布到我的 Controller 。

这是我的 StartUp.cs 配置(为简洁起见，我省略了不相关的代码)

public void ConfigureServices(IServiceCollection services)
{
    services.AddCors(options =>
    {
        options.AddPolicy(
            "CorsPolicy",
            builder =>
                builder
                .AllowAnyOrigin()
                .AllowAnyHeader()
                .AllowAnyMethod()
                .AllowCredentials()
        );
    });

    services.AddAuthentication();
    services.AddMvcCore()
        .AddAuthorization(options => {...});
    services.AddAuthentication("Bearer")
        .AddIdentityServerAuthentication(options => {...});

    services.AddSignalR();
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseCors("CorsPolicy");
    app.UseAuthentication();

    app.UseSignalR(routes =>
    {
        routes.MapHub<SampleHub>("/hubs/sample");
    });

    app.UseMvc();
}

这是我的示例中心

public interface ISampleHubClient 
{
    Task receiveMessage(SampleRequest msg);
}

public class SampleHub : Hub<ISampleHubClient>
{
    private static string _connectionId;

    public async Task Subscribe(string groupName)
    {
        await Groups.AddAsync(Context.ConnectionId, groupName);

        await Clients.Client(Context.ConnectionId).receiveMessage("Subscribed to " + groupName);
    }

    /// <inheritdoc />
    public Task Send(SampleRequest msg)
    {
        ConsoleColor.Green.WriteLine("Send : " + _connectionId);

        return Clients.Group(msg.Group).receiveMessage(msg);
    }
}

这是我的 Angular 组件代码:

import { HubConnection } from '@aspnet/signalr-client';

@Component({})
export class SignalRTestComponent implements OnInit {
    private hubConnection: HubConnection;

    ngOnInit() {
        this.initHub();
    }

    initHub()
    {
        let self = this;
        var signalrBaseUri = "https://localhost:44301/hubs/sample";

       this.hubConnection = new HubConnection(signalrBaseUri);

        this.hubConnection
        .start() // <- Failure here
        .then(() =>{
             self.hubConnection.invoke("Subscribe", this.groupName);
        })
        .catch(err => { console.log("INVOKE FAILED");console.error(err);});             
    })
    .catch(err => 
    {
        console.log('Error while establishing connection :(');
        console.log(err);
    });

    this.hubConnection.on('receiveMessage', (receivedMessage: SampleMessage) => {
        console.log("Message received : ");
        console.log(sampleMessage);
    });
}
}

任何帮助将不胜感激

Answer 1

问题是，the npm package has been renamed从 @aspnet/signalr-client 到 @aspnet/signalr。更改为这个新包并修复导入对我有用(至少摆脱 OPTIONS 调用错误。

从“@aspnet/signalr”导入 { HubConnection}