DOCUMENT:Q151771 04-AUG-2001 [visualc] TITLE :LICREQST.EXE Requesting a License Key from an Object PRODUCT :Microsoft C Compiler PROD/VER:winnt:4.1,5.0,6.0 OPER/SYS: KEYWORDS:kbole kbSample kbCOMt kbLicensing kbMFC kbVC400 kbVC410 kbVC500 kbVC600 kbFAQ kbGrpDSMF ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual C++, version 4.1 - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 ------------------------------------------------------------------------------- SUMMARY ======= The LicReqst sample illustrates how to use the IClassFactory2 interface to request an object's License key. The following file is available for download from the Microsoft Download Center: Licreqst.exe For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file. NOTE: Use the -d option when running Licrqst.exe to decompress the file and recreate the proper directory structure. MORE INFORMATION ================ The LicReqst sample is a dialog-based MFC application that illustrates how to use the IClassFactory2 interface to request an object's License key. LicReqst displays the ProgID of each of the currently registered ActiveX controls in a Listbox. When one of the displayed ProgID's is selected, an instance of the corresponding control is created and then asked for it's License key. If a valid key is returned, LicReqst displays the key and enables the "Copy to Clipboard" button that allows the License key to be copied to the Clipboard. The License key can then easily be pasted into code that uses the CWnd::CreateControl method to dynamically create an instance of the Control. LicReqst creates a textual version of the License key data in the form of a declaration of an array of WCHAR when copying the key to the Clipboard. This is done because the License key data could contain non-printable characters. A human-readable version of the License key data is also provided for reference and is included inside a Comment block in the final string that is copied to the Clipboard. For example, if an object uses the string "Copyright (c) 1994" (without the quotes) for its License key, LicReqst would generate the following block of text that could be copied to and pasted from the Clipboard: /* Copyright (c) 1994 */ WCHAR pwchLicenseKey[] = { 0x0043, 0x006F, 0x0070, 0x0079, 0x0072, 0x0069, 0x0067, 0x0068, 0x0074, 0x0020, 0x0028, 0x0063, 0x0029, 0x0020, 0x0031, 0x0039, 0x0039, 0x0034, 0x0020 }; You can use the previous block of text in code that creates an instance of the Licensed object, and you can use the pwchLicenseKey variable to specify the object's License key. For example, if MFC code is dynamically creating an instance of a Licensed ActiveX Control using the Create method of a Visual C++ Component Gallery generated wrapper class, the pwchLicenseKey variable can be used in the Create call like this: BSTR bstrLicense = ::SysAllocStringLen(pwchLicenseKey, sizeof(pwchLicenseKey)/sizeof(WCHAR)); m_MyControl.Create(NULL, WS_VISIBLE, CRect(10,10,10,10), this, 2, NULL, FALSE, bstrLicense); ::SysFreeString(bstrLicense); Note how a BSTR is created from the pwchLicenseKey variable and how the BSTR is then used for the License key parameter in the Create call. NOTE: The code in this sample that generates the text copied to the Clipboard makes the assumption that it is being executed on a little endian system (Intel x86-class processors). Because of this, it will not work correctly on big endian system. For these systems, it is still possible to use the Helper function used internally by the sample to request the License key from an object. The sample uses a Helper function called RequestLicenseKey() to get the License key from an object based on its ProgID. The source code for the RequestLicenseKey() function is shown later in the Sample Code section. To find other locations of interest in the sample source code, use the Find in Files feature of the Visual C++ Developer Studio to search for the string named SAMPLE CODE. This string has been used to tag each of the modified sections in the source code. NOTE: Running the LicReqst sample on a licensed machine to obtain an object's License key, and then distributing that key to allow applications to be developed on other non-licensed machines, may be a violation of established copyrights. For more information and to determine if an object's License key can be legally redistributed, refer to the License Agreement provided with the object or contact the creator of the object. Sample Code ----------- // Compile options needed: none /////////////////////////////////////////////////////////////////////// // SAMPLE CODE - Implementation of the RequestLicenseKey function // // The RequestLicenseKey function uses the IClassFactory2 interface // to request a License key from an object specified by its ProgID. // // Parameters: // // [out] BSTR& bstrLicenseKey // Upon return, this BSTR will contain either a valid // License key or an error message. It is the caller's // responsibility to call ::SysFreeString on this BSTR. // // [in] CString strProgID // Specifies the ProgID of the object from which to request the // License key. // // // Return Value: // // A BOOL specifying success or failure. If TRUE is returned, // the License key was retrieved successfully and the // bstrLicenseKey parameter contains a valid License key. If // FALSE is returned, the License key was not retrieved // successfully and the bstrLicenseKey parameter contains a // descriptive error string. // // Regardless of the return value, it is the responsibility of // the caller to call ::SysFreeString on the returned bstrLicenseKey // parameter. // BOOL RequestLicenseKey(BSTR& bstrLicenseKey, CString strProgID) { USES_CONVERSION; LPCLASSFACTORY2 pClassFactory; CLSID clsid; BOOL bValidKeyReturned = FALSE; // Get the CLSID of the specified ProgID. if (SUCCEEDED(CLSIDFromProgID(T2OLE(strProgID), &clsid))) { // Create an instance of the object and query it for // the IClassFactory2 interface. if (SUCCEEDED(CoGetClassObject(clsid, CLSCTX_INPROC_SERVER, NULL, IID_IClassFactory2, (LPVOID *)(&pClassFactory)))) { LICINFO licinfo; // Check to see if this object has a runtime License key. if (SUCCEEDED(pClassFactory->GetLicInfo(&licinfo))) { if (licinfo.fRuntimeKeyAvail) { HRESULT hr; // The object has a runtime License key, so request it. hr = pClassFactory->RequestLicKey(0, &bstrLicenseKey); if (SUCCEEDED(hr)) { if(bstrLicenseKey == NULL) bstrLicenseKey = ::SysAllocString( L""); else // You have the license key. bValidKeyReturned = TRUE; } else // Requesting the License key failed. switch(hr) { case E_NOTIMPL: bstrLicenseKey = ::SysAllocString( L""); break; case E_UNEXPECTED: bstrLicenseKey = ::SysAllocString( L""); break; case E_OUTOFMEMORY: bstrLicenseKey = ::SysAllocString( L""); break; case CLASS_E_NOTLICENSED: bstrLicenseKey = ::SysAllocString( L""); break; default: bstrLicenseKey = ::SysAllocString( L""); } } else bstrLicenseKey = ::SysAllocString( L""); } else bstrLicenseKey = ::SysAllocString( L""); // Make sure you release the reference to the class factory. pClassFactory->Release(); } else bstrLicenseKey = ::SysAllocString( L""); } else bstrLicenseKey = ::SysAllocString( L""); // Return a BOOL specifying whether or not you were able to get a // valid license key. return bValidKeyReturned; } REFERENCES ========== For more information, please see: OLE Programmer's Reference; search on IClassFactory2 interface; CWnd::CreateControl method. Additional query words: ====================================================================== Keywords : kbole kbSample kbCOMt kbLicensing kbMFC kbVC400 kbVC410 kbVC500 kbVC600 kbFAQ kbGrpDSMFCATL Technology : kbVCsearch kbAudDeveloper kbVC410 kbVC500 kbVC600 kbVC32bitSearch kbVC500Search Version : winnt:4.1,5.0,6.0 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.