SocketsHttpHandler.ConnectCallback Propriedade

Definição

Obtém ou define um retorno de chamada personalizado usado para abrir novas conexões.

public:
 property Func<System::Net::Http::SocketsHttpConnectionContext ^, System::Threading::CancellationToken, System::Threading::Tasks::ValueTask<System::IO::Stream ^>> ^ ConnectCallback { Func<System::Net::Http::SocketsHttpConnectionContext ^, System::Threading::CancellationToken, System::Threading::Tasks::ValueTask<System::IO::Stream ^>> ^ get(); void set(Func<System::Net::Http::SocketsHttpConnectionContext ^, System::Threading::CancellationToken, System::Threading::Tasks::ValueTask<System::IO::Stream ^>> ^ value); };
public Func<System.Net.Http.SocketsHttpConnectionContext,System.Threading.CancellationToken,System.Threading.Tasks.ValueTask<System.IO.Stream>>? ConnectCallback { get; set; }
member this.ConnectCallback : Func<System.Net.Http.SocketsHttpConnectionContext, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask<System.IO.Stream>> with get, set
Public Property ConnectCallback As Func(Of SocketsHttpConnectionContext, CancellationToken, ValueTask(Of Stream))

Valor da propriedade

Um método de retorno de chamada para criar um fluxo.

Exceções

Uma operação já foi iniciada na instância atual.

A instância atual foi descartada.

Exemplos

O exemplo de código a seguir define tcp KeepAlive no subjacente Socket.

static async Task Main()
{
    using SocketsHttpHandler handler = new SocketsHttpHandler();

    handler.ConnectCallback = async (ctx, ct) =>
    {
        DnsEndPoint dnsEndPoint = ctx.DnsEndPoint;
        IPAddress[] addresses = await Dns.GetHostAddressesAsync(dnsEndPoint.Host, dnsEndPoint.AddressFamily, ct);
        var s = new Socket(SocketType.Stream, ProtocolType.Tcp) { NoDelay = true };
        try
        {
            s.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, true);
            s.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.TcpKeepAliveTime, 5);
            s.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.TcpKeepAliveInterval, 5);
            s.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.TcpKeepAliveRetryCount, 5);

            await s.ConnectAsync(addresses, dnsEndPoint.Port, ct);
            return new NetworkStream(s, ownsSocket: true);
        }
        catch
        {
            s.Dispose();
            throw;
        }
    };

    // Create an HttpClient object
    using HttpClient client = new HttpClient(handler);

    // Call asynchronous network methods in a try/catch block to handle exceptions
    try
    {
        HttpResponseMessage response = await client.GetAsync("https://learn.microsoft.com/");

        response.EnsureSuccessStatusCode();

        string responseBody = await response.Content.ReadAsStringAsync();
        Console.WriteLine($"Read {responseBody.Length} characters");
    }
    catch (HttpRequestException e)
    {
        Console.WriteLine("\nException Caught!");
        Console.WriteLine($"Message: {e.Message} ");
    }
}

Aplica-se a