IHttpFileInfo 接口

通过为服务器上缓存的文件添加特定于文件的信息来扩展 IHttpCacheSpecificData 接口。

语法

class IHttpFileInfo : public IHttpCacheSpecificData  

方法

下表列出了 类公开 IHttpFileInfo 的方法。

名称	说明
AccessCheck	返回一个值，该值指示用户是否可以访问相应的文件。
CheckIfFileHasChanged	返回一个值，该值指示相应的文件自加载到文件缓存后是否已更改。
递减TTL	(继承自 IHttpCacheSpecificData.)
DereferenceCacheData	（从 IHttpCacheSpecificData 继承。）
GetAttributes	检索接口的相应文件 IHttpFileInfo 的属性。
GetCacheKey	（从 IHttpCacheSpecificData 继承。）
GetETag	检索接口的相应文件的 IHttpFileInfo 实体标记。
GetFileBuffer	返回从相应文件加载的内存中的缓冲区。
GetFileHandle	返回相应文件的文件句柄。
GetFilePath	返回接口引用 IHttpFileInfo 的文件的物理路径。
GetFlushed	（从 IHttpCacheSpecificData 继承。）
GetHttpCacheAllowed	返回一个值，该值指示是否可以缓存相应的文件。
GetLastModifiedString	检索接口的相应文件的 IHttpFileInfo 上次修改字符串。
GetLastModifiedTime	检索接口的相应文件的 IHttpFileInfo 上次修改时间结构。
GetModuleContextContainer	返回对应文件的 IHttpModuleContextContainer 指针。
GetSize	检索接口的相应文件 IHttpFileInfo 的大小。
GetVrPath	返回相应文件的虚拟路径。
GetVrToken	返回相应文件的虚拟令牌。
ReferenceCacheData	（从 IHttpCacheSpecificData 继承。）
ResetTTL	（从 IHttpCacheSpecificData 继承。）
SetFlushed	（从 IHttpCacheSpecificData 继承。）

派生类

此接口不包含派生类。

备注

注册请求或响应事件的 CHttpModule 派生类在事件的相应virtual方法上接收 IHttpContext 指针。 可以通过调用 IHttpContext：：GetFileInfo 方法检索IHttpFileInfo指针。

示例

下面的代码示例演示如何使用 IHttpContext：：GetFileInfo 方法创建检索指向接口的指针的 IHttpFileInfo HTTP 模块。 然后，该示例向 IHttpFileInfo Web 客户端显示数据。

#pragma warning( disable : 4290 )
#pragma warning( disable : 4530 )

#define _WINSOCKAPI_
#include <windows.h>
#include <io.h>
#include <sal.h>
#include <httpserv.h>

#include <string>
using namespace std;

// The CConvert class mirrors the Convert class that is 
// defined in the .NET Framework. It converts primitives 
// and other data types to wstring types.
class CConvert
{
public:
    // The ToString method converts a HANDLE to a wstring.
    // h: the HANDLE to convert to a wstring.
    // return: the HANDLE as a wstring.
    static wstring ToString(HANDLE h)
    {
        // If the HANDLE is NULL, return the "NULL" string.
        if (NULL == h)
        {
            return L"NULL";
        }

        // If the HANDLE is not valid, return 
        // the INVALID_HANDLE_VALUE as a string.
        if (INVALID_HANDLE_VALUE == h)
        {
            return L"INVALID_HANDLE_VALUE";
        }

        // The HANDLE is valid.
        return L"valid";
    }
    
    // The ToString method converts a FILETIME pointer to a wstring.
    // fileTime: the FILETIME pointer to convert to a wstring.
    // return: the FILETIME pointer as a wstring.
    static wstring ToString(FILETIME* fileTime)
    {
        // If fileTime is NULL, return the empty string.
        if (NULL == fileTime)
        {
            return L"NULL";
        }

        // Convert the FILETIME to a local time, and 
        // then convert that local time to a wstring.
        SYSTEMTIME stUTC;
        SYSTEMTIME stLocal;
        FileTimeToSystemTime(fileTime, &stUTC);
        SystemTimeToTzSpecificLocalTime(NULL, &stUTC, &stLocal);        

        // Create a wstring to return.  Note: wsprintf 
        // can be also used. However, it is more difficult 
        // to handle both UNICODE and non-UNICODE correctly.
        wstring timeString =
            ToString(stLocal.wMonth) +
            wstring(L"/")            +
            ToString(stLocal.wDay)   +
            wstring(L"/")            +
            ToString(stLocal.wYear)  +
            wstring(L"  ")           +
            ToString(stLocal.wHour)  +
            wstring(L":")            +
            ToString(stLocal.wMinute);

        // Return the FILETIME data as a wstring.
        return timeString;
    }
    
    // The ToString method converts a 
    // ULARGE_INTEGER pointer to a wstring.
    // ui: the ULARGE_INTEGER pointer to convert to a string.
    // return: the ULARGE_INTEGER pointer as a string.
    static wstring ToString(ULARGE_INTEGER* ui)
    {
        // Return the empty string if the 
        // ULARGE_INTEGER pointer is NULL.
        if (NULL == ui)
        {
            return L"NULL";
        }
        
        // Return the low-order part to a wstring.
        return (ToString(ui->LowPart));
    }
    
    // The ToString method converts a PCSTR to a wstring.
    // pcstr: the PCSTR to convert to a wstring.
    // return: the PCSTR as a wstring.
    static wstring ToString(PCSTR pcstr)
    {
        // Return the empty string 
        // if the PCSTR is NULL.
        if (NULL == pcstr)
        {
            return L"NULL";
        }

        // Get the length of the string to copy.
        size_t length = strlen(pcstr);
        // Create a new double-byte character 
        // array of length plus 1.
        wchar_t* newText = new wchar_t[length+1];

        // Copy the source into the sink string.
        for (size_t i = 0; i < length; ++i)
        {
            newText[i] = pcstr[i];
        }

        // Terminate the string with the NULL character.
        newText[length] = '\0';
        // Get a wstring from the new double-byte string.
        wstring wText = newText;
        // Call delete on the newText pointer 
        // and set this pointer to NULL.
        delete[] newText;
        newText = NULL;

        // Return the wstring copy.
        return wText;
    }
        
    // The ToString method converts a long to a wstring.
    // l: the long value to convert to a wstring.
    // return: the long as a wstring.
    static wstring ToString(long l)
    {
        WCHAR str[256];
        str[0] = '\0';        
        _ltow_s(l, str, 256, 10);
        return str;
    }
        
    // The ToString method converts a DWORD to a wstring.
    // d: the DWORD value to convert to a wstring.
    // return: the DWORD as a wstring.
    static wstring ToString(DWORD d)
    {
        return ToString((long)d);
    }
    
    // The ToString method converts an LPCGUID to a wstring.
    // guid: the LPCGUID value to convert to a wstring.
    // return: The LPCGUID as a wstring; otherwise, L"" if
    // guid is NULL.
    static wstring ToString(LPCGUID guid)
    {
        // If the GUID is NULL, return the empty string.
        if (NULL == guid)
        {
            return L"NULL";
        }

        // Create a WCHAR array to write the GUID to.
        WCHAR guidString[256];
        // Initialize the zero-based index of the 
        // guidString to the null-terminating character 
        // because the StringFromGUID2 may fail.
        guidString[0] = '\0';
        // Convert the GUID to a string of the form "{...}".
        int characters = StringFromGUID2(*guid, guidString, 256);
        // Return the guidString as a wstring.
        return guidString;
    }

    // The ToString method converts a BOOL to a wstring.
    // b: the BOOL value to convert to a wstring.
    // return: L"true" for true; otherwise, L"false" for false.
    static wstring ToString(BOOL b)
    {
        return (b) ? L"true" : L"false";
    }

    // The ToByteString converts a double-byte 
    // character string to a single-byte string.
    // str: the double-byte string to convert.
    // return: a single-byte string copied from str.
    static string ToByteString(const wstring& str)
    {
        // Get the length of the 
        // double-byte string.
        size_t length = str.length();

        // Create a temporary char pointer.
        char* byteChar = new char[length+1];
        byteChar[0] = '\0';
        // Copy the double-byte character string
        // into the single-byte string.        
        size_t charsReturned = 0;
        wcstombs_s(&charsReturned, byteChar, 
                   length+1, str.c_str(), length+1);
        // Create a string to return.
        string retString = byteChar;
        // Delete the temporary string and
        // set that string to NULL.
        delete[] byteChar;
        byteChar = NULL;

        // Return the single-byte string.
        return retString;
    }

    // The ToString method converts a USHORT to a wstring.
    // u: the USHORT value to convert to a wstring.
    // return: the value of u as a wstring.
    static wstring ToString(USHORT u)
    {
        return (ToString((long)u));
    }

    // The ToString method converts a 
    // const BYTE pointer to a wstring.
    // bytes: the BYTE pointer to convert.
    // return: the value of bytes as a wstring.
    static wstring ToString(const BYTE* bytes)
    {
        return (ToString((PCSTR)bytes));    
    }

    // The ToString method converts 
    // a PCWSTR to a wstring.
    // pcwstr: the PCWSTR to convert.
    // return: L"NULL" if the pcwstr
    // parameter is NULL; otherwise, 
    // pcwstr converted to a wstring.
    static wstring ToString(PCWSTR pcwstr)
    {
        // If the pcwstr parameter
        // is NULL, return L"NULL".
        if (NULL == pcwstr)
        {
            return L"NULL";
        }

        // Implicitly convert the 
        // PCWSTR to a wstring.
        return pcwstr;
    }
};

// The CResponseWriter class writes 
// text to the response stream.
class CResponseWriter
{
public:
    // Creates the CResponseWriter class.
    // response: the IHttpResponse 
    // pointer to write to.
    // throws: a _com_error exception if
    // the IHttpResponse pointer is NULL.
    CResponseWriter(IHttpResponse* response)
        throw (_com_error)
    {
        // If the response is NULL,
        // throw an exception.
        if (NULL == response)
        {
            ThrowOnFail(E_INVALIDARG);            
        }

        // Set the internal response.
        m_response = response;
    }

    // The destructor for the CResponseWriter
    // class. The CResponseWriter method 
    // sets the IHttpResponse pointer to NULL.
    virtual ~CResponseWriter()
    {
        m_response = NULL;
    }
    
    // The Write method writes the 
    // PCSTR to the response stream.
    // pszValue: the PCSTR to write.
    // throws: a _com_error if the 
    // Write method fails.
    void Write
    (
        PCSTR pszValue        
    ) throw (_com_error)
    {
        // The string must not be 
        // NULL, and its length must 
        // be greater than 0.
        if ((NULL == pszValue) || 
            (strlen(pszValue) < 1))            
        {
            // Throw an invalid argument
            // exception.
            ThrowOnFail(E_INVALIDARG);                        
        }        

        // Create a data chunk structure.
        HTTP_DATA_CHUNK dataChunk;
        // Set the chunk to a chunk in memory.
        dataChunk.DataChunkType = 
            HttpDataChunkFromMemory;

        // Set the chunk to 
        // the pszValue parameter.
        dataChunk.FromMemory.pBuffer = 
            (PVOID)pszValue;
        // Set the chunk size 
        // to the pszValue length.
        dataChunk.FromMemory.BufferLength = 
            (USHORT)strlen(pszValue);
                
        // Declare and initialize OUT 
        // parameters for the WriteEntityChunks 
        // method.
        DWORD pcbSent = 0;
        BOOL pfCompletionExpected = FALSE;

        // Write the entity chunks to
        // the response stream.
        HRESULT hr =
            m_response->WriteEntityChunks
                (&dataChunk,
                 1,
                 FALSE,
                 FALSE,
                 &pcbSent,
                 &pfCompletionExpected);

        // Throw an exception if the call
        // to WriteEntityChunks is not a 
        // success.
        ThrowOnFail(hr);        
    }
    
    // The WriteLine method writes a string
    // and newline characters to the response steam.
    // pszValue: the PCSTR string to write.
    // throws: a _com_error if the PCSTR 
    // or the newline characters are not 
    // written to the response stream.
    void WriteLine
    (
        PCSTR pszValue        
    ) throw (_com_error)
    {
        // Try to write the pszValue parameter.
        Write(pszValue);        
        
        // Try to write the newline characters.
        Write("\r\n");
    }
    
    // Convenience method that writes a name 
    // and value pair to the response stream.
    // name: the name of the parameter.
    // value: the value of the parameter.
    // throws: a _com_error exception if
    // the response stream is not written.
    void WriteLine
    (
        const wstring& name,
        const wstring& value
    ) throw (_com_error)
    {
        // Convert the UNICODE strings 
        // to mutlibyte strings.
        string nameMulti = 
            CConvert::ToByteString(name);
        string valueMulti = 
            CConvert::ToByteString(value);

        // Create the string to write.
        string writeString =
            nameMulti + 
            string(":  ") + 
            valueMulti;

        // Write the line to
        // the response stream.
        WriteLine(writeString.c_str());        
    }

    // Tests an HRESULT for success.
    // hr: the HRESULT value to inspect.
    // throws: a _com_error if the HRESULT
    // parameter is not S_OK.
    static void ThrowOnFail(HRESULT hr)
    {
        if (FAILED(hr))
        {
            _com_error ce(hr);
            throw ce;
        }
    }
private:
    // Specify the IHttpResponse
    // pointer to write to.
    IHttpResponse* m_response;
};

// The MyHttpModule class extends the CHttpModule 
// class and handles response processing.  This 
// class handles retrieving an IHttpFileInfo pointer 
// from the IHttpContext pointer during the overridden 
// OnSendResponse method, and writes the IHttpFileInfo 
// data to the response stream.
class MyHttpModule : public CHttpModule
{
public:
    // The MyHttpModule method is the public 
    // constructor for the MyHttpModule class.
    MyHttpModule()
    {

    }

    // The OnSendResponse method 
    // handles respose processing.
    // pHttpContext: an IHttpContext pointer.
    // pProvider: an ISendResponseProvider pointer.
    // return: RQ_NOTIFICATION_FINISH_REQUEST if the 
    // IHttpFileInfo pointer can be retrieved from the 
    // pHttpContext parameter; otherwise, 
    // RQ_NOTIFICATION_CONTINUE.
    REQUEST_NOTIFICATION_STATUS OnSendResponse
    (
        IN IHttpContext* pHttpContext,
        IN OUT ISendResponseProvider* pProvider
    )
    {
        // Use the UNREFERENCED_PARAMETER macro since
        // the pProvider parameter is never used.
        UNREFERENCED_PARAMETER(pProvider);

        if (NULL == pHttpContext)
        {
            return RQ_NOTIFICATION_CONTINUE;
        }
        
        // Get an IHttpFileInfo pointer 
        // from the IHttpContext pointer.
        IHttpFileInfo* fileInfo = 
            pHttpContext->GetFileInfo();

        // Get the IHttpResponse pointer 
        // from the IHttpContext pointer.
        IHttpResponse* response = 
            pHttpContext->GetResponse();

        // Both the IHttpFileInfo pointer
        // and IHttpResponse pointer are
        // required for processing.
        if ((NULL == fileInfo) ||
            (NULL == response))
        {
            return RQ_NOTIFICATION_CONTINUE;
        }
 
        // Clear the existing response stream.        
        response->Clear();

        // Set the response header to plain text.
        HRESULT hr = 
            response->SetHeader(HttpHeaderContentType, 
                                "text/plain", 
                                (USHORT)strlen("text/plain"), 
                                 TRUE);

        // If the SetHeader method fails,
        // call the SetStatus with an error code.
        if (FAILED(hr))
        {
            response->SetStatus(500, 
                                "IHttpResponse::SetHeader", 
                                0, hr);
            return RQ_NOTIFICATION_CONTINUE;
        }

        // The CResponseWriter will throw a 
        // com_exception if it cannot be created, 
        // or if the response stream cannot be written. 
        // Create a new CResponseWriter, and wrap 
        // all calls into that CResponseWriter,
        // with a try-catch statement.
        try
        {
            // Declare a writer for 
            // the response stream.
            CResponseWriter writer(response);

            // Declare a HANDLE for 
            // the user and initialize 
            // that HANDLE to NULL.
            HANDLE userHandle = NULL;

            // Get the IHttpUser pointer from 
            // the IHttpContext pointer.
            IHttpUser* user =
                pHttpContext->GetUser();

            // If the IHttpUser pointer 
            // is not NULL, reset the 
            // primary token HANDLE.
            if (NULL != user)
            {
                userHandle = 
                    user->GetPrimaryToken();
            }            

            // Call the AccessCheck method
            // on the IHttpFileInfo pointer.
            hr = fileInfo->AccessCheck(userHandle, NULL);

            // Convert the HRESULT to a wstring.
            wstring validAccess = CConvert::ToString(hr);

            // Write access information 
            // to the response stream.
            writer.WriteLine(L"Access", validAccess);

            // Call the CheckIfFileHasChanged method
            // on the IHttpFileInfo pointer.
            BOOL fileChanged = 
                fileInfo->CheckIfFileHasChanged(userHandle);

            // Convert the Boolean to a wstring.
            wstring changed = 
                CConvert::ToString(fileChanged);

            // Write file changed information
            // to the response stream.
            writer.WriteLine(L"File Changed", changed);

            // Call the GetAttributes method 
            // on the IHttpFileInfo pointer.
            DWORD attributes = 
                fileInfo->GetAttributes();

            // Convert the attribute
            // to a wstring.
            wstring attributesString = 
                CConvert::ToString(attributes);

            // Write attribute information 
            // to the response stream.
            writer.WriteLine(L"Attributes", attributesString);        

            // Convert a readonly file to a wstring.
            wstring readOnlyString =
                CConvert::ToString((BOOL)attributes & _A_RDONLY);

            // Write read-only information to
            // the response stream.
            writer.WriteLine(L"Read only", readOnlyString);

            // Convert a hidden file to a wstring.
            wstring hiddenFileString =
                CConvert::ToString((BOOL)attributes & _A_HIDDEN);

            // Write hidden information
            // to the response stream.
            writer.WriteLine(L"Hidden", hiddenFileString);

            // Convert archive information
            // to a wstring.
            wstring archiveString =
                CConvert::ToString((BOOL)attributes & _A_ARCH);

            // Write the archive information
            // to the response stream.
            writer.WriteLine(L"Archive", archiveString);

            // Declare a USHORT and 
            // initialize it to 0 for a 
            // call to the GetETag method.
            USHORT cchETag = 0;
            // Call the GetETag metohd on
            // the IHttpFileInfo pointer.
            PCSTR pszETag = fileInfo->GetETag(&cchETag);

            // Convert the etag information
            // to a wstring.
            wstring etagString =
                CConvert::ToString(pszETag);

            // Write the etag information
            // to the response stream.
            writer.WriteLine(L"ETag", etagString);        

            // Convert the USHORT to a wstring.
            wstring cchString = 
                CConvert::ToString(cchETag);

            // Write the etag information
            // to the response stream.
            writer.WriteLine(L"ETag Value", cchString);

            // Call the GetFileBuffer method
            // on the IHttpFileInfo pointer.
            const BYTE* fileBuffer = 
                fileInfo->GetFileBuffer();

            // Convert the const BYTE 
            // pointer to a wstring.
            wstring fileString =
                CConvert::ToString(fileBuffer);

            // Write the file buffer to
            // the response stream.
            writer.WriteLine(L"File Buffer", fileString);            

            // Call the GetFileHandle method
            // on the IHttpFileInfo pointer.
            HANDLE fileHandle = 
                fileInfo->GetFileHandle();

            // Convert the file 
            // HANDLE to a wstring.
            wstring fileHandleString = 
                CConvert::ToString(fileHandle);

            // Write the file information
            // to the response stream.
            writer.WriteLine(L"File Handle", fileHandleString);

            // Call the GetFilePath method
            // on the IHttpFileInfo pointer.
            PCWSTR filePathPCWSTR = 
                fileInfo->GetFilePath();

            // Convert the file 
            // path to a wstring.
            wstring filePath = 
                CConvert::ToString(filePathPCWSTR);

            // Write the file path to
            // the response stream.
            writer.WriteLine(L"File Path", filePath);        

            // Call the GetHttpCacheAllowed method
            // on the IHttpFileInfo pointer.
            DWORD timeToLive = 0;
            BOOL cacheAllowed = 
                fileInfo->GetHttpCacheAllowed(&timeToLive);

            // Convert the Boolean 
            // to a wstring.
            wstring cacheAllowedString = 
                CConvert::ToString(cacheAllowed);

            // Write the Boolean to
            // the response stream.
            writer.WriteLine(L"Cache Allowed",
                             cacheAllowedString);

            // Convert the time-to-live
            // to a wstring.
            wstring timeToLiveString = 
                CConvert::ToString(timeToLive);

            // Write the time-to-live information
            // to the response stream.
            writer.WriteLine(L"Time-to-Live",
                             timeToLiveString);

            // Call the GetLastModifiedString
            // method on the IHttpFileInfo pointer.
            PCSTR lastModifiedPCSTR = 
                fileInfo->GetLastModifiedString();

            // Convert the modified 
            // information to a wstring.
            wstring lastModifiedString =
                CConvert::ToString(lastModifiedPCSTR);

            // Write the modification information
            // to the response stream.
            writer.WriteLine(L"Last Modified String",
                             lastModifiedString);

            // Call the GetLastModifiedTime method
            // on the IHttpFileInfo pointer.
            FILETIME fileTime;
            fileInfo->GetLastModifiedTime(&fileTime);

            // Convert the FILETIME 
            // structure to a wstring.
            wstring lastModifiedTimeString = 
                CConvert::ToString(&fileTime);

            // Write the last modified time
            // information to the response stream.
            writer.WriteLine(L"Last Modified Time",
                             lastModifiedTimeString);

            // Get the IHttpModuleContextContainer
            // from the IHttpFileInfo pointer.
            IHttpModuleContextContainer* contextContainer =
                fileInfo->GetModuleContextContainer();        

            // Convert the IHttpModuleContextContainer
            // pointer to a wstring.
            wstring contextString =
                CConvert::ToString(NULL != contextContainer);

            // Write the context data to
            // the response stream.
            writer.WriteLine(L"Context", contextString);

            // Call the GetSize method on
            // the IHttpFileInfo pointer.
            ULARGE_INTEGER sizeInteger;
            fileInfo->GetSize(&sizeInteger);

            // Convert the size to a wstring.
            wstring size = 
                CConvert::ToString(&sizeInteger);

            // Write the size information
            // to the response stream.
            writer.WriteLine(L"Size", size);

            // Call the GetVrPath method on 
            // the IHttpFileInfo pointer.
            PCWSTR vrPathPCWSTR = 
                fileInfo->GetVrPath();

            // Convert the VR path to a wstring.
            wstring vrPath = 
                CConvert::ToString(vrPathPCWSTR);

            // Write the VR path information
            // to the response stream.
            writer.WriteLine(L"VR Path", vrPath);        

            // Call the GetVrToken method 
            // on the IHttpFileInfo pointer.
            HANDLE vrToken = 
                fileInfo->GetVrToken();

            // Convert the VR token to a wstring.
            wstring vrTokenString = 
                CConvert::ToString(vrToken);

            // Write the token information 
            // to the response stream.
            writer.WriteLine(L"VR Token", vrTokenString);
        }
        catch (_com_error& ce)
        {
            // Attempt to get the 
            // description of the error.
            _bstr_t description = 
                ce.Description();

            // Print the description if 
            // it is not empty.
            if (0 == description.length())
            {
                description = ce.ErrorMessage();            
            }
            
            // Set an error status on the 
            // IHttpResponse pointer.
            response->SetStatus(500, description, 0, ce.Error());            
        }
                
        // Return RQ_NOTIFICATION_FINISH_REQUEST, which 
        // will terminate any additional request processing.
        return RQ_NOTIFICATION_FINISH_REQUEST;
    }
protected:    
    // The MyHttpModule is the protected virtual
    // constructor for the MyHttpModule class.
    virtual ~MyHttpModule()
    {

    }
};

// The MyHttpModuleFactory class implements the IHttpModuleFactory 
// interface, and creates a new MyHttpModule pointer, where this
// MyHttpModule listens for RQ_SEND_RESPONSE events.
class MyHttpModuleFactory : public IHttpModuleFactory
{
public:
    // The RegisterGlobalModule method creates a new 
    // MyHttpModuleFactory pointer, assigns that pointer 
    // as the factory on the pModuleInfo parameter, and
    // registers for RQ_SEND_RESPONSE events.
    // dwServerVersion: the current server version.
    // pModuleInfo: the IHttpModuleRegistrationInfo 
    // used for requesting notifications.
    // pGlobalInfo: the IHttpServer pointer.
    static HRESULT RegisterGlobalModule
    (
        DWORD dwServerVersion,
        IHttpModuleRegistrationInfo* pModuleInfo,
        IHttpServer* pGlobalInfo
    )
    {
        // Create a new MyHttpModuleFactory pointer.
        MyHttpModuleFactory* factory =
            new MyHttpModuleFactory;

        // If the factory is NULL, return a
        // return a ERROR_NOT_ENOUGH_MEMORY 
        // errror.
        if (NULL == factory)
        {
            return HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY);
        }

        // Return the value from calling the 
        // SetRequestNotifications method by 
        // passing the factory for RQ_SEND_RESPONSE
        // events.
        return pModuleInfo->SetRequestNotifications(
            factory,
            RQ_SEND_RESPONSE,
            0);
    }

    // The GetHttpModule method creates a new MyHttpModule 
    // pointer and sets the ppModule with this pointer.
    // ppModule: the OUT parameter which 
    // accepts a new CHttpModule subclass.
    // pAllocator: the IModuleAllocator pointer, 
    // which is unused in this implementation.
    virtual HRESULT GetHttpModule
    (
        OUT CHttpModule** ppModule, 
        IN IModuleAllocator* pAllocator
    )
    {
        // Call the UNREFERENCED_PARAMETER with 
        // the IModuleAllocator pointer, because
        // this parameter is never used.
        UNREFERENCED_PARAMETER(pAllocator);        

        // Create a new MyHttpModule pointer and assign
        // it to the dereferenced ppModule pointer.
        *ppModule = new MyHttpModule;

        // If the dereferenced ppModule is NULL 
        // then heap memory is exhausted. Return
        // an ERROR_NOT_ENOUGH_MEMORY error.
        if (NULL == *ppModule)
        {
            return HRESULT_FROM_WIN32(ERROR_NOT_ENOUGH_MEMORY);
        }

        // Creating a new MyHttpModule pointer 
        // was successful; return S_OK.
        return S_OK;       
    }

    // The Terminate method must be implemented
    // by IHttpModuleFactory implementers, 
    // and calls delete on this.
    virtual void Terminate()
    {
        delete this;
    }

private:
    // The MyHttpModuleFactory is the 
    // protected constructor for the 
    // MyHttpModuleFactory class.
    MyHttpModuleFactory()
    {

    }

    // The MyHttpModuleFactory method is the 
    // protected virtual destructor for the 
    // MyHttpModuleFactory class.
    virtual ~MyHttpModuleFactory()
    {

    }
};

// The RegisterModule method is the 
// main entry point for the DLL.
// dwServerVersion: the current server version.
// pModuleInfo: the current 
// IHttpModuleRegistrationInfo pointer.
// pGlobalInfo: the current IHttpServer pointer.
// return: the HRESULT value returned from 
// the MyHttpModuleFactory::RegisterGlobalModule
// static method.
HRESULT
__stdcall
RegisterModule
(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo* pModuleInfo,
    IHttpServer* pGlobalInfo
)
{    
    // Register for global events using the MyHttpModuleFactory 
    // class' static RegisterGlobalModule method.
    return MyHttpModuleFactory::RegisterGlobalModule
        (dwServerVersion, pModuleInfo, pGlobalInfo);  
}

以下文本是上述代码示例的数据输出示例。

HTTP/1.1 200 OK  
content-Type:text/plain  
Server: Microsoft-IIS/7.0  
Date: Thu, 15 Dec 2005 22:22:09 GMT  
Content-Length: 374  
  
Access: -123456789  
File Changed: false  
Attributes: 32  
ETag: "1234567890abcde:0"  
ETag Value: 19  
File Handle: INVALID_HANDLE_VALUE  
File Path: C:\INETPUB\WWWROOT\IISSTART.HTM  
Cache Allowed: true  
Time-to-Live: -1  
Last Modified String: Tue, 13 Dec 2005 10:57:41 GMT  
Last Modified Time: 12/13/2005 02:57  
Module Container: valid  
VR Path: NULL  
VR Token: NULL  

模块必须导出 RegisterModule 函数。 可以通过为项目创建模块定义 (.def) 文件导出此函数，也可以使用 开关编译模块 /EXPORT:RegisterModule 。 有关详细信息，请参阅 演练：使用本机代码创建Request-Level HTTP 模块。

可以选择使用调用约定编译代码， __stdcall (/Gz) 而不是为每个函数显式声明调用约定。

继承层次结构

IHttpCacheSpecificData

IHttpFileInfo

要求

类型	说明
客户端	- Windows Vista 上的 IIS 7.0 - Windows 7 上的 IIS 7.5 - Windows 8 上的 IIS 8.0 - Windows 10 上的 IIS 10.0
服务器	- Windows Server 2008 上的 IIS 7.0 - Windows Server 2008 R2 上的 IIS 7.5 - Windows Server 2012 上的 IIS 8.0 - Windows Server 2012 R2 上的 IIS 8.5 - Windows Server 2016 上的 IIS 10.0
产品	- IIS 7.0、IIS 7.5、IIS 8.0、IIS 8.5、IIS 10.0 - IIS Express 7.5、IIS Express 8.0、IIS Express 10.0
Header	Httpserv.h

另请参阅

Web 服务器核心接口
IHttpTokenEntry 接口