HttpListener.GetContext 方法

  • 參考

定義

命名空間:
System.Net
組件:
System.Net.HttpListener.dll
組件:
System.dll
組件:
netstandard.dll
來源:
HttpListener.Managed.cs
來源:
HttpListener.Managed.cs
來源:
HttpListener.Managed.cs

等候傳入要求，並在收到要求時傳回。

public:
 System::Net::HttpListenerContext ^ GetContext();
public System.Net.HttpListenerContext GetContext ();
member this.GetContext : unit -> System.Net.HttpListenerContext
Public Function GetContext () As HttpListenerContext

傳回

HttpListenerContext

HttpListenerContext 物件，代表用戶端要求。

例外狀況

HttpListenerException

Win32 函式呼叫失敗。 請檢查例外狀況的 ErrorCode 屬性，以判斷造成例外狀況的原因。

InvalidOperationException

這個物件尚未啟動或目前已停止。

-或-

HttpListener 沒有任何要回應的統一資源識別元 (URI) 前置詞。

ObjectDisposedException

這個物件已經關閉。

範例

下列程式代碼範例示範如何呼叫這個方法。

// This example requires the System and System.Net namespaces.
public static void SimpleListenerExample(string[] prefixes)
{
    if (!HttpListener.IsSupported)
    {
        Console.WriteLine ("Windows XP SP2 or Server 2003 is required to use the HttpListener class.");
        return;
    }
    // URI prefixes are required,
    // for example "http://contoso.com:8080/index/".
    if (prefixes == null || prefixes.Length == 0)
      throw new ArgumentException("prefixes");

    // Create a listener.
    HttpListener listener = new HttpListener();
    // Add the prefixes.
    foreach (string s in prefixes)
    {
        listener.Prefixes.Add(s);
    }
    listener.Start();
    Console.WriteLine("Listening...");
    // Note: The GetContext method blocks while waiting for a request.
    HttpListenerContext context = listener.GetContext();
    HttpListenerRequest request = context.Request;
    // Obtain a response object.
    HttpListenerResponse response = context.Response;
    // Construct a response.
    string responseString = "<HTML><BODY> Hello world!</BODY></HTML>";
    byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
    // Get a response stream and write the response to it.
    response.ContentLength64 = buffer.Length;
    System.IO.Stream output = response.OutputStream;
    output.Write(buffer,0,buffer.Length);
    // You must close the output stream.
    output.Close();
    listener.Stop();
}

Public Shared Sub SimpleListenerExample(prefixes As String())
    If Not HttpListener.IsSupported Then
        Console.WriteLine("Windows XP SP2 or Server 2003 is required to use the HttpListener class.")
        Return
    End If
    ' URI prefixes are required,
    ' for example "http://contoso.com:8080/index/".
    If prefixes Is Nothing Or prefixes.Length = 0 Then
        Throw New ArgumentException("prefixes")
    End If

    ' Create a listener
    Dim listener = New HttpListener()

    For Each s As String In prefixes
        listener.Prefixes.Add(s)
    Next
    listener.Start()
    Console.WriteLine("Listening...")
    ' Note: The GetContext method blocks while waiting for a request.
    Dim context As HttpListenerContext = listener.GetContext()
    Console.WriteLine("Listening...")
    ' Obtain a response object
    Dim request As HttpListenerRequest = context.Request
    ' Construct a response.
    Dim response As HttpListenerResponse = context.Response
    Dim responseString As String = "<HTML><BODY> Hello world!</BODY></HTML>"
    Dim buffer As Byte() = System.Text.Encoding.UTF8.GetBytes(responseString)
    ' Get a response stream and write the response to it.
    response.ContentLength64 = buffer.Length
    Dim output As System.IO.Stream = response.OutputStream
    output.Write(buffer, 0, buffer.Length)
    'You must close the output stream.
    output.Close()
    listener.Stop()
End Sub

備註

在呼叫這個方法之前，您必須呼叫 Start 方法，並新增至少一個 URI 前置詞來接聽，方法是將 URI 字串新增至 HttpListenerPrefixCollection 屬性所傳回的 Prefixes 。 如需前置詞的詳細描述，請參閱 HttpListener 類別概觀。

此方法會在等候傳入要求時封鎖。 如果您想要在個別線程) 以異步方式處理傳入要求 (，讓應用程式不會封鎖，請使用 BeginGetContext 方法。

給呼叫者的注意事項

在應用程式中啟用網路追蹤時，這個成員會輸出追蹤資訊。 如需詳細資訊，請參閱 .NET Framework 中的網路追蹤。

適用於