HELLCTRL.CPP (HELLCTRL OLE Sample)

/*************************************************************************

  • Automation Controller that uses vtable binding.

  • Controls the HELLO automation object.

  • hellctrl.cpp

  • Written by Microsoft Product Support Services, Windows Developer Support

  • (c) Copyright Microsoft Corp. 1994 All Rights Reserved

  • ***********************************************************************/

#define STRICT

#include <windows.h>

#include <windowsx.h>

#ifdef WIN16

#include <ole2.h>

#include <compobj.h>

#include <dispatch.h>

#include <variant.h>

#include <olenls.h>

#include <commdlg.h>

#endif

#include <initguid.h>

#include "tlb.h"

#include "hellctrl.h"

// Globals

HINSTANCE g_hinst; // Instance of application

HWND g_hwnd; // Toplevel window handle

// String resource buffers

TCHAR g_szTitle[STR_LEN]; // Main window caption

TCHAR g_szResult[STR_LEN]; // "Result"

TCHAR g_szError[STR_LEN]; // "Error"

/*

* WinMain

*

* Purpose:

* Main entry point of application. Should register the app class

* if a previous instance has not done so and do any other one-time

* initializations.

*

*/

int APIENTRY WinMain (HINSTANCE hinst, HINSTANCE hinstPrev, LPSTR lpCmdLine, int nCmdShow)

{

MSG msg;

// It is recommended that all OLE applications set

// their message queue size to 96. This improves the capacity

// and performance of OLE's LRPC mechanism.

int cMsg = 96; // Recommend msg queue size for OLE

while (cMsg && !SetMessageQueue(cMsg)) // take largest size we can get.

cMsg -= 8;

if (!cMsg)

return -1; // ERROR: we got no message queue

// Load string constants

LoadString(hinst, IDS_PROGNAME, g_szTitle, STR_LEN);

LoadString(hinst, IDS_RESULT, g_szResult, STR_LEN);

LoadString(hinst, IDS_ERROR, g_szError, STR_LEN);

if (!hinstPrev)

if (!InitApplication(hinst))

return (FALSE);

if(OleInitialize(NULL) != NOERROR)

return FALSE;

if (!InitInstance(hinst, nCmdShow))

return (FALSE);

while (GetMessage(&msg, NULL, NULL, NULL))

{

TranslateMessage(&msg);

DispatchMessage(&msg);

}

OleUninitialize();

return (msg.wParam); // Returns the value from PostQuitMessage

}

/*

* InitApplication

*

* Purpose:

* Registers window class

*

* Parameters:

* hinst hInstance of application

*

* Return Value:

* TRUE if initialization succeeded, FALSE otherwise.

*/

BOOL InitApplication (HINSTANCE hinst)

{

WNDCLASS wc;

wc.style = CS_DBLCLKS;

wc.lpfnWndProc = MainWndProc;

wc.cbClsExtra = 0;

wc.cbWndExtra = 0;

wc.hInstance = hinst;

wc.hIcon = LoadIcon(hinst, TEXT("ControlIcon"));

wc.hCursor = LoadCursor(NULL, IDC_ARROW);

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);

wc.lpszMenuName = TEXT("ControlMenu");

wc.lpszClassName = TEXT("MainWndClass");

return RegisterClass(&wc);

}

/*

* InitInstance

*

* Purpose:

* Creates and shows main window

*

* Parameters:

* hinst hInstance of application

* nCmdShow specifies how window is to be shown

*

* Return Value:

* TRUE if initialization succeeded, FALSE otherwise.

*/

BOOL InitInstance (HINSTANCE hinst, int nCmdShow)

{

g_hinst = hinst;

// Create Main Window

g_hwnd = CreateWindow(TEXT("MainWndClass"), g_szTitle,

WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT, CW_USEDEFAULT,

400, 200,

NULL, NULL, hinst, NULL);

if (!g_hwnd)

return FALSE;

ShowWindow(g_hwnd, nCmdShow);

UpdateWindow(g_hwnd);

return TRUE;

}

/*

* MainWndProc

*

* Purpose:

* Window procedure for main window

*

*/

LRESULT CALLBACK MainWndProc (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)

{

static IHello FAR* phello = NULL;

HRESULT hr;

LPUNKNOWN punk;

switch (msg)

{

case WM_COMMAND:

switch (wParam)

{

case IDM_CREATEHELLO:

// Create Hello object and QueryInterface for IHello interface.

hr = CoCreateInstance(CLSID_Hello, NULL, CLSCTX_SERVER,

IID_IUnknown, (void FAR* FAR*)&punk);

if (FAILED(hr))

{

MessageBox(NULL, TEXT("CoCreateInstance"), g_szError, MB_OK);

return 0L;

}

hr = punk->QueryInterface(IID_IHello, (void FAR* FAR*)&phello);

if (FAILED(hr))

{

MessageBox(NULL, TEXT("QueryInterface(IID_IHello)"), g_szError, MB_OK);

punk->Release();

return 0L;

}

punk->Release();

return 0L;

case IDM_SETVISIBLE:

// Set Visible property to TRUE

hr = phello->put_Visible(TRUE);

if (FAILED(hr))

DisplayError(phello);

return 0L;

case IDM_SETINVISIBLE:

// Set visible property to FALSE

hr = phello->put_Visible(FALSE);

if (FAILED(hr))

DisplayError(phello);

return 0L;

case IDM_GETHELLOMESSAGE:

{

// Access Hello Message property and display it

// in a MessageBox

BSTR bstr = NULL; // BSTR must be intialized before passing

// to get_HelloMessage.

hr = phello->get_HelloMessage(&bstr);

if (FAILED(hr))

DisplayError(phello);

else MessageBox(NULL, FROM_OLE_STRING(bstr), g_szResult, MB_OK);

// Caller is responsible for freeing parameters and return values.

if (bstr)

SysFreeString(bstr);

return 0L;

}

case IDM_SAYHELLO:

// Invoke SayHello method

hr = phello->SayHello();

if (FAILED(hr))

DisplayError(phello);

return 0L;

case IDM_RELEASEHELLO:

// Release the Hello object

phello->Release();

phello = NULL;

return 0L;

}

break;

case WM_INITMENUPOPUP:

{

HMENU hmenu = (HMENU)wParam;

if (LOWORD(lParam) != 0)

return 0L;

// Enable or gray the appropriate menu items. phello indicates if an automation object

// is currently being controlled.

EnableMenuItem(hmenu, IDM_CREATEHELLO, MF_BYCOMMAND | (phello?MF_GRAYED:MF_ENABLED));

EnableMenuItem(hmenu, IDM_SETVISIBLE, MF_BYCOMMAND | (phello?MF_ENABLED:MF_GRAYED));

EnableMenuItem(hmenu, IDM_SETINVISIBLE, MF_BYCOMMAND | (phello?MF_ENABLED:MF_GRAYED));

EnableMenuItem(hmenu, IDM_GETHELLOMESSAGE, MF_BYCOMMAND | (phello?MF_ENABLED:MF_GRAYED));

EnableMenuItem(hmenu, IDM_SAYHELLO, MF_BYCOMMAND | (phello?MF_ENABLED:MF_GRAYED));

EnableMenuItem(hmenu, IDM_RELEASEHELLO, MF_BYCOMMAND | (phello?MF_ENABLED:MF_GRAYED));

return 0L;

}

case WM_DESTROY:

if (phello)

phello->Release();

PostQuitMessage(0);

break;

default:

return DefWindowProc(hwnd, msg, wParam, lParam);

}

return NULL;

}

/*

* DisplayError

*

* Purpose:

* Obtains Rich Error Information about the automation error from

* the IErrorInfo interface.

*

*/

  • oid DisplayError(IHello FAR* phello)

{

IErrorInfo FAR* perrinfo;

BSTR bstrDesc;

HRESULT hr;

/*

// This is commented out because the OLE 2.02 release did not

// include remoting code for ISupportErrorInfo.

ISupportErrorInfo FAR* psupporterrinfo;

hr = phello->QueryInterface(IID_ISupportErrorInfo, (LPVOID FAR*)&psupporterrinfo);

if (FAILED(hr))

{

MessageBox(NULL, TEXT("QueryInterface(IID_ISupportErrorInfo)"), g_szError, MB_OK);

return;

}

hr = psupporterrinfo->InterfaceSupportsErrorInfo(IID_IHello);

if (hr != NOERROR)

{

psupporterrinfo->Release();

return;

}

psupporterrinfo->Release();

// In this example only the error description is obtained and displayed.

// See the IErrorInfo interface fo other information that is available.

hr = GetErrorInfo(0, &perrinfo);

if (FAILED(hr))

return;

hr = perrinfo->GetDescription(&bstrDesc);

if (FAILED(hr))

{

perrinfo->Release();

return;

}

MessageBox(NULL, FROM_OLE_STRING(bstrDesc), g_szError, MB_OK);

SysFreeString(bstrDesc);

}

#ifdef WIN32

#ifndef UNICODE

char* ConvertToAnsi(OLECHAR FAR* szW)

{

static char achA[STRCONVERT_MAXLEN];

WideCharToMultiByte(CP_ACP, 0, szW, -1, achA, STRCONVERT_MAXLEN, NULL, NULL);

return achA;

}

OLECHAR* ConvertToUnicode(char FAR* szA)

{

static OLECHAR achW[STRCONVERT_MAXLEN];

MultiByteToWideChar(CP_ACP, 0, szA, -1, achW, STRCONVERT_MAXLEN);

return achW;

}

#endif

#endif

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