DefaultHttpHandler DefaultHttpHandler DefaultHttpHandler DefaultHttpHandler Class

定義

表示預設 HTTP 處理常式的屬性和方法。Represents the properties and methods of a default HTTP handler.

public ref class DefaultHttpHandler : System::Web::IHttpAsyncHandler
public class DefaultHttpHandler : System.Web.IHttpAsyncHandler
type DefaultHttpHandler = class
    interface IHttpAsyncHandler
    interface IHttpHandler
Public Class DefaultHttpHandler
Implements IHttpAsyncHandler
繼承
DefaultHttpHandlerDefaultHttpHandlerDefaultHttpHandlerDefaultHttpHandler
實作

範例

下列程式碼範例示範如何藉由DefaultHttpHandler衍生自類別, 來實作為自訂的 HTTP 處理常式。The following code example demonstrates how to implement a customized HTTP handler by deriving from the DefaultHttpHandler class.

public class AsyncDefaultHttpHandler : DefaultHttpHandler
{
    private HttpContext _context;

    public override IAsyncResult BeginProcessRequest(
      HttpContext context, AsyncCallback callback, object state)
    {
        AsyncResultSample ar = new AsyncResultSample(callback, state);
        _context = context;

        return ar;
    }

    public override void EndProcessRequest(IAsyncResult result)
    {
        _context.Response.Write("EndProcessRequest called.");
    }

    // This method should not be called asynchronously.
    public override void ProcessRequest(HttpContext context)
    {
        throw new InvalidOperationException(
                  "Asynchronous processing failed.");
    }

    // Enables pooling when set to true
    public override bool IsReusable
    {
        get { return true; }
    }
}

// Tracks state between the begin and end calls.
class AsyncResultSample : IAsyncResult
{
    private AsyncCallback callback = null;
    private Object asyncState;
    private Boolean isCompleted;

    internal AsyncResultSample(AsyncCallback cb, Object state)
    {
        this.callback = cb;
        asyncState = state;
        isCompleted = false;
    }

    public object AsyncState
    {
        get
        {
            return asyncState;
        }
    }

    public bool CompletedSynchronously
    {
        get
        {
            return false;
        }
    }

    public WaitHandle AsyncWaitHandle
    {
        get
        {
            throw new InvalidOperationException(
                      "ASP.NET should not use this property .");
        }
    }

    public bool IsCompleted
    {
        get
        {
            return isCompleted;
        }
    }

    internal void SetCompleted()
    {
        isCompleted = true;
        if (callback != null)
        {
            callback(this);
        }
    }

}
Public Class defaulthttpexampleVB
    Inherits DefaultHttpHandler

    Private _context As HttpContext

    Public Overrides Function BeginProcessRequest _
        (ByVal context As HttpContext, _
         ByVal callback As AsyncCallback, _
         ByVal state As Object) As IAsyncResult

        Dim ar As New AsyncResultSample(callback, state)
        _context = context

        Return (ar)
    End Function

    Public Overrides Sub EndProcessRequest(ByVal result As IAsyncResult)
        _context.Response.Write("EndProcessRequest called.")
    End Sub

    ' This method should not be called asynchronously.
    Public Overrides Sub ProcessRequest(ByVal context As HttpContext)
        Throw New InvalidOperationException _
          ("Asynchronous processing failed.")
    End Sub

    ' Enables pooling when set to true
    Public Overrides ReadOnly Property IsReusable() As Boolean
        Get
            Return True
        End Get
    End Property
End Class

' Tracks state between the begin and end calls.
Class AsyncResultSample
    Implements IAsyncResult
    Private callback As AsyncCallback = Nothing
    Private _asyncState As Object
    Private _isCompleted As Boolean

    Friend Sub New(ByVal cb As AsyncCallback, ByVal state As Object)
        Me.callback = cb
        _asyncState = state
        _isCompleted = False
    End Sub

    Public ReadOnly Property AsyncState() As Object _
      Implements IAsyncResult.AsyncState
        Get
            Return _asyncState
        End Get
    End Property

    Public ReadOnly Property CompletedSynchronously() _
      As Boolean Implements IAsyncResult.CompletedSynchronously
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property AsyncWaitHandle() _
      As WaitHandle Implements IAsyncResult.AsyncWaitHandle
        Get
            Throw New InvalidOperationException _
              ("ASP.NET should not use this property .")
        End Get
    End Property

    Public ReadOnly Property IsCompleted() _
      As Boolean Implements IAsyncResult.IsCompleted
        Get
            Return IsCompleted
        End Get
    End Property

    Friend Sub SetCompleted()
        _isCompleted = True
        If (callback <> Nothing) Then
            callback(Me)
        End If
    End Sub
End Class

備註

當要求攔截已透過 Internet Information Services (IIS) 6.0 設定, 而且沒有明確系結套用至要求的延伸模組時,物件就會攔截HTTP管線中的傳入要求。DefaultHttpHandlerA DefaultHttpHandler object intercepts incoming requests in the HTTP pipeline when both request interception has been configured through Internet Information Services (IIS) 6.0 and no explicit bindings apply to the requested extension.

要求攔截可以透過 IIS 6.0 中引進的萬用字元應用程式對應功能來設定。Request interception can be set up through the wildcard application mapping feature introduced in IIS 6.0. 如需詳細資訊, 請在MSDN Library中搜尋使用萬用字元應用程式對應重新對應 URL 的相關資訊。For more information, search the MSDN Library for information about using wildcard application maps to remap a URL.

DefaultHttpHandler類別會執行介面來IHttpAsyncHandler提供非同步要求處理。The DefaultHttpHandler class implements the IHttpAsyncHandler interface to provide asynchronous request processing. 如需 HTTP 處理常式的一般資訊, 請參閱Http 處理常式和 Http 模組總覽For general information about HTTP handlers, see HTTP Handlers and HTTP Modules Overview. 此外, 如需詳細資訊, 請參閱下列各項:Additionally, for more information see the following:

類別可以衍生DefaultHttpHandler自類別, 以提供自訂的要求處理。Classes can derive from the DefaultHttpHandler class to provide customized handling of requests. 衍生自的DefaultHttpHandler非同步 HTTP 處理常式可能會覆BeginProcessRequest寫方法, 以變更要求的處理方式。An asynchronous HTTP handler that is derived from the DefaultHttpHandler could override the BeginProcessRequest method to change how requests are processed.

DefaultHttpHandler不會使用 ASP.NET 錯誤。A DefaultHttpHandler does not use ASP.NET errors. 使用 IIS 錯誤或專利 ISAPI 自訂錯誤機制的現有內容將不會變更。Existing content that uses IIS errors or a propriety ISAPI custom error mechanism would work unchanged.

建構函式

DefaultHttpHandler() DefaultHttpHandler() DefaultHttpHandler() DefaultHttpHandler()

初始化 DefaultHttpHandler 類別的新執行個體。Initializes a new instance of the DefaultHttpHandler class.

屬性

Context Context Context Context

取得與目前 DefaultHttpHandler 物件關聯的內容。Gets the context that is associated with the current DefaultHttpHandler object.

ExecuteUrlHeaders ExecuteUrlHeaders ExecuteUrlHeaders ExecuteUrlHeaders

取得隨要求傳輸之要求標頭和要求值的集合。Gets a collection of request headers and request values to transfer along with the request.

IsReusable IsReusable IsReusable IsReusable

取得布林值,指出其他要求是否可以使用 DefaultHttpHandler 類別目前的執行個體。Gets a Boolean value indicating that another request can use the current instance of the DefaultHttpHandler class.

方法

BeginProcessRequest(HttpContext, AsyncCallback, Object) BeginProcessRequest(HttpContext, AsyncCallback, Object) BeginProcessRequest(HttpContext, AsyncCallback, Object) BeginProcessRequest(HttpContext, AsyncCallback, Object)

啟始對 HTTP 處理常式的非同步呼叫 (Asynchronous Call)。Initiates an asynchronous call to the HTTP handler.

EndProcessRequest(IAsyncResult) EndProcessRequest(IAsyncResult) EndProcessRequest(IAsyncResult) EndProcessRequest(IAsyncResult)

提供非同步處理序的結束方法。Provides an end method for an asynchronous process.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

判斷指定的物件是否等於目前的物件。Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

做為預設雜湊函式。Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

(Inherited from Object)
OnExecuteUrlPreconditionFailure() OnExecuteUrlPreconditionFailure() OnExecuteUrlPreconditionFailure() OnExecuteUrlPreconditionFailure()

當先決條件防止 DefaultHttpHandler 物件處理要求時呼叫。Called when preconditions prevent the DefaultHttpHandler object from processing a request.

OverrideExecuteUrlPath() OverrideExecuteUrlPath() OverrideExecuteUrlPath() OverrideExecuteUrlPath()

覆寫目前要求的目標 URL。Overrides the target URL for the current request.

ProcessRequest(HttpContext) ProcessRequest(HttpContext) ProcessRequest(HttpContext) ProcessRequest(HttpContext)

DefaultHttpHandler 物件可以處理 HTTP Web 要求。Enables a DefaultHttpHandler object to process of HTTP Web requests.

ToString() ToString() ToString() ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(Inherited from Object)

適用於

另請參閱