sdk/samples/all in on code/Visual Studio 2010/CppShellExtContextMenuHandler/dllmain.cpp

   1 /****************************** Module Header ******************************\
   2 Module Name:  dllmain.cpp
   3 Project:      CppShellExtContextMenuHandler
   4 Copyright (c) Microsoft Corporation.
   5
   6 The file implements DllMain, and the DllGetClassObject, DllCanUnloadNow,
   7 DllRegisterServer, DllUnregisterServer functions that are necessary for a COM
   8 DLL.
   9
  10 DllGetClassObject invokes the class factory defined in ClassFactory.h/cpp and
  11 queries to the specific interface.
  12
  13 DllCanUnloadNow checks if we can unload the component from the memory.
  14
  15 DllRegisterServer registers the COM server and the context menu handler in
  16 the registry by invoking the helper functions defined in Reg.h/cpp. The
  17 context menu handler is associated with the .cpp file class.
  18
  19 DllUnregisterServer unregisters the COM server and the context menu handler.
  20
  21 This source is subject to the Microsoft Public License.
  22 See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  23 All other rights reserved.
  24
  25 THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
  26 EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
  27 WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
  28 \***************************************************************************/
  29
  30 #include <windows.h>
  31 #include <Guiddef.h>
  32 #include "ClassFactory.h"           // For the class factory
  33 #include "Reg.h"
  34
  35
  36 // {BFD98515-CD74-48A4-98E2-13D209E3EE4F}
  37 // When you write your own handler, you must create a new CLSID by using the
  38 // "Create GUID" tool in the Tools menu, and specify the CLSID value here.
  39 const CLSID CLSID_FileContextMenuExt =
  40 { 0xBFD98515, 0xCD74, 0x48A4, { 0x98, 0xE2, 0x13, 0xD2, 0x09, 0xE3, 0xEE, 0x4F } };
  41
  42
  43 HINSTANCE   g_hInst     = NULL;
  44 long        g_cDllRef   = 0;
  45
  46
  47 BOOL APIENTRY DllMain(HMODULE hModule, DWORD dwReason, LPVOID lpReserved)
  48 {
  49         switch (dwReason)
  50         {
  51         case DLL_PROCESS_ATTACH:
  52         // Hold the instance of this DLL module, we will use it to get the
  53         // path of the DLL to register the component.
  54         g_hInst = hModule;
  55         DisableThreadLibraryCalls(hModule);
  56         break;
  57         case DLL_THREAD_ATTACH:
  58         case DLL_THREAD_DETACH:
  59         case DLL_PROCESS_DETACH:
  60                 break;
  61         }
  62         return TRUE;
  63 }
  64
  65
  66 //
  67 //   FUNCTION: DllGetClassObject
  68 //
  69 //   PURPOSE: Create the class factory and query to the specific interface.
  70 //
  71 //   PARAMETERS:
  72 //   * rclsid - The CLSID that will associate the correct data and code.
  73 //   * riid - A reference to the identifier of the interface that the caller
  74 //     is to use to communicate with the class object.
  75 //   * ppv - The address of a pointer variable that receives the interface
  76 //     pointer requested in riid. Upon successful return, *ppv contains the
  77 //     requested interface pointer. If an error occurs, the interface pointer
  78 //     is NULL.
  79 //
  80 STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, void **ppv)
  81 {
  82     HRESULT hr = CLASS_E_CLASSNOTAVAILABLE;
  83
  84     if (IsEqualCLSID(CLSID_FileContextMenuExt, rclsid))
  85     {
  86         hr = E_OUTOFMEMORY;
  87
  88         ClassFactory *pClassFactory = new ClassFactory();
  89         if (pClassFactory)
  90         {
  91             hr = pClassFactory->QueryInterface(riid, ppv);
  92             pClassFactory->Release();
  93         }
  94     }
  95
  96     return hr;
  97 }
  98
  99
 100 //
 101 //   FUNCTION: DllCanUnloadNow
 102 //
 103 //   PURPOSE: Check if we can unload the component from the memory.
 104 //
 105 //   NOTE: The component can be unloaded from the memory when its reference
 106 //   count is zero (i.e. nobody is still using the component).
 107 //
 108 STDAPI DllCanUnloadNow(void)
 109 {
 110     return g_cDllRef > 0 ? S_FALSE : S_OK;
 111 }
 112
 113
 114 //
 115 //   FUNCTION: DllRegisterServer
 116 //
 117 //   PURPOSE: Register the COM server and the context menu handler.
 118 //
 119 STDAPI DllRegisterServer(void)
 120 {
 121     HRESULT hr;
 122
 123     wchar_t szModule[MAX_PATH];
 124     if (GetModuleFileName(g_hInst, szModule, ARRAYSIZE(szModule)) == 0)
 125     {
 126         hr = HRESULT_FROM_WIN32(GetLastError());
 127         return hr;
 128     }
 129
 130     // Register the component.
 131     hr = RegisterInprocServer(szModule, CLSID_FileContextMenuExt,
 132         L"CppShellExtContextMenuHandler.FileContextMenuExt Class",
 133         L"Apartment");
 134     if (SUCCEEDED(hr))
 135     {
 136         // Register the context menu handler. The context menu handler is
 137         // associated with the .cpp file class.
 138         hr = RegisterShellExtContextMenuHandler(L".cpp",
 139             CLSID_FileContextMenuExt,
 140             L"CppShellExtContextMenuHandler.FileContextMenuExt");
 141     }
 142
 143     return hr;
 144 }
 145
 146
 147 //
 148 //   FUNCTION: DllUnregisterServer
 149 //
 150 //   PURPOSE: Unregister the COM server and the context menu handler.
 151 //
 152 STDAPI DllUnregisterServer(void)
 153 {
 154     HRESULT hr = S_OK;
 155
 156     wchar_t szModule[MAX_PATH];
 157     if (GetModuleFileName(g_hInst, szModule, ARRAYSIZE(szModule)) == 0)
 158     {
 159         hr = HRESULT_FROM_WIN32(GetLastError());
 160         return hr;
 161     }
 162
 163     // Unregister the component.
 164     hr = UnregisterInprocServer(CLSID_FileContextMenuExt);
 165     if (SUCCEEDED(hr))
 166     {
 167         // Unregister the context menu handler.
 168         hr = UnregisterShellExtContextMenuHandler(L".cpp",
 169             CLSID_FileContextMenuExt);
 170     }
 171
 172     return hr;
 173 }