adosample.cpp

来自「《Windows CE 权威指南》（作者：(美)CHRIS MUENCH」· C++ 代码 · 共 679 行 · 第 1/2 页

	// <BOOK Necessary due to Compatibility Wrapper in ADOCE30.h>
	const IID IID__Recordset20 =    {0x4BEB93D5,0x28D8,0x11D1,{0x83,0x21,0x00,0xA0,0x24,0xA8,0x81,0x10}};
	// </BOOK Necessary due to Compatibility Wrapper in ADOCE30.h>
	TCHAR tsADOCE30ConnProgID[]= TEXT("ADOCE.Connection.3.0");
	TCHAR tsADOCE30RSProgID[]= TEXT("ADOCE.Recordset.3.0");
	TCHAR tsADOCE20RSProgID[]= TEXT("ADOCE.Recordset.1");
	CLSID tClsid;
	VariantInit(&varConn1);
	VariantInit(&vaEmpty);
	HRESULT hr;
	
	if (FAILED(CoInitializeEx(NULL, COINIT_MULTITHREADED)))
			return FALSE; 
	// Step1 - Open/Create a database
	// *********************************************
	hr = CLSIDFromProgID( tsADOCE30ConnProgID, &tClsid );
	if (!FAILED(hr))
	{	// ADOCE3.0 found !!
		hr=CoCreateInstance(tClsid,NULL,CLSCTX_INPROC_SERVER, 
							IID__Connection, (LPVOID *)&Conn1);
		hr=Conn1->put_Provider(TEXT("cedb"));
		hr=Conn1->Open(TEXT(""),TEXT(""),TEXT(""),adOpenUnspecified);

		hr=CLSIDFromProgID( tsADOCE30RSProgID, &tClsid );
		hr=CoCreateInstance(tClsid,NULL,CLSCTX_INPROC_SERVER, 
							IID__Recordset,(LPVOID *)&Rs1);
		varConn1.pdispVal=Conn1;
		varConn1.vt=VT_DISPATCH;
		hr=Rs1->put_ActiveConnection(varConn1);
		bADOCE3=TRUE;
	}
	else
	{	// Is at ADOCE2.0 there ?
		hr=CLSIDFromProgID( tsADOCE20RSProgID, &tClsid );
	    hr=CoCreateInstance(tClsid,NULL,CLSCTX_INPROC_SERVER, 
							IID__Recordset20 ,(LPVOID *)&Rs1);
	}
	if (FAILED(hr)) return FALSE; // No ADOCE there... leave

	hr=Rs1->Open(_variant_t(TEXT("DROP TABLE Book841")),vaEmpty, 
				 adOpenForwardOnly , adLockReadOnly ,adCmdUnknown);

	hr=Rs1->Open(_variant_t(TEXT("CREATE TABLE Book841 (MyInt integer, MyDate datetime, MyString varchar(200), MyBlob long varbinary)")),
				 _variant_t(TEXT("")),adOpenForwardOnly , adLockReadOnly , adCmdUnknown);
	if (FAILED(hr)) return FALSE;	// Error handling
	wprintf(TEXT("Step1 Complete: Database Created\n\r"));

	// Step2 - Writing a record
	// *********************************************
	hr=Rs1->Open(_variant_t(TEXT("select * from Book841")),_variant_t(TEXT("")),
				 adOpenKeyset , adLockOptimistic , adCmdUnknown);
	if (FAILED(hr)) return FALSE;	// Error handling

	hr=Rs1->AddNew(vaEmpty,vaEmpty);

	hr=Rs1->get_Fields(&Fields);
	hr=Fields->get_Count(&FldCnt);
	for (int i=0;i<FldCnt;i++)
	{
		if (bADOCE3)
			hr=Fields->get_Item(_variant_t((long)i),&Field);
		else
			hr=Fields->get_Item(_variant_t((long)i),(struct Field **)&Field20);
		VariantInit(&value);
		switch (i)
		{
			case 0:
					if (bADOCE3)
						hr=Field->put_Value(_variant_t(-1L));
					else
						hr=Field20->put_Value(_variant_t(-1L));
				break;
			case 1:
					value.vt=VT_DATE;
					GetSystemTime(&MyTime); 
					SystemTimeToVariantTime(&MyTime,&value.date);
					if (bADOCE3)
						hr=Field->put_Value(value);
					else
						hr=Field20->put_Value(value);
				break;
			case 2:
					if (bADOCE3)
						hr=Field->put_Value(_variant_t(TEXT("This is a string")));
					else
						hr=Field20->put_Value(_variant_t(TEXT("This is a string")));
				break;
			case 3:
					if (bADOCE3)
						hr=Field->put_Value(_variant_t(TEXT("This is a blob-string")));
					else
						hr=Field20->put_Value(_variant_t(TEXT("This is a blob-string")));
				break;
			default: break;
		}
	}
	hr=Rs1->Update(vaEmpty,vaEmpty);
	if (FAILED(hr)) return FALSE;	// Error handling
	// or 
	//hr=Rs1->Open(_variant_t(TEXT("INSERT INTO Book841 "
 	//		         "(MyInt,MyDate,MyString) VALUES "
	// 		         "(1,'1/1/1999 12:12','This is a string')")),
	//			     _variant_t(TEXT("")),
	//				adOpenForwardOnly , adLockReadOnly , 1);
	wprintf(TEXT("Step2 Complete: New Record Written\n\r"));

	// Step3 - Reading a record
	// *********************************************
	Rs1->MoveFirst();

	int RecCnt=0;
	Rs1->get_BOF(&tBOF);
	Rs1->get_EOF(&tEOF);
	if(!(tBOF==VARIANT_TRUE && tEOF==VARIANT_TRUE))
	{
		while (tEOF!=VARIANT_TRUE)
		{
			hr=Rs1->get_Fields(&Fields);
			hr=Fields->get_Count(&FldCnt);
			for (int i=0;i<FldCnt;i++)
			{
				VariantInit(&value);
				if (bADOCE3)
				{
					hr=Fields->get_Item(_variant_t((long)i),&Field);
					hr=Field->get_Value(&value);
				}
				else
				{
					hr=Fields->get_Item(_variant_t((long)i),(struct Field **)&Field20);
					hr=Field20->get_Value(&value);
				}
				VariantChangeType(&vaEmpty,&value,0,VT_BSTR);
				if (vaEmpty.vt==VT_BSTR)
					wprintf(TEXT("Property #%d = <%s>\n\r"),i,vaEmpty.bstrVal);
			}
			Rs1->MoveNext(); 
			Rs1->get_EOF(&tEOF);
			RecCnt++;
		}
	}
	wprintf(TEXT("Step3: Read %d Records\n\r"),RecCnt);
	
	// Step4 - Closing the Database
	// *********************************************
	Rs1->Close();
	Rs1->Release();
	if (bADOCE3)
		Conn1->Release();
	CoUninitialize(); 
	wprintf(TEXT("Step4 Complete: All closed\n\r"),RecCnt);
// </BOOK_ADDON Chapter 8.4.1> *************************************************

	// Perform application initialization:
	if (!InitInstance (hInstance, nCmdShow)) 
	{
		return FALSE;
	}
	
	hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_ADOSAMPLE);

	// Main message loop:
	while (GetMessage(&msg, NULL, 0, 0)) 
	{
		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) 
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}

	return msg.wParam;
}

//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance, LPTSTR szWindowClass)
{
	WNDCLASS	wc;

    wc.style			= CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc		= (WNDPROC) WndProc;
    wc.cbClsExtra		= 0;
    wc.cbWndExtra		= 0;
    wc.hInstance		= hInstance;
    wc.hIcon			= LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ADOSAMPLE));
    wc.hCursor			= 0;
    wc.hbrBackground	= (HBRUSH) GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName		= 0;
    wc.lpszClassName	= szWindowClass;

	return RegisterClass(&wc);
}

//
//  FUNCTION: InitInstance(HANDLE, int)
//
//  PURPOSE: Saves instance handle and creates main window
//
//  COMMENTS:
//
//    In this function, we save the instance handle in a global variable and
//    create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
	HWND	hWnd;
	TCHAR	szTitle[MAX_LOADSTRING];			// The title bar text
	TCHAR	szWindowClass[MAX_LOADSTRING];		// The window class name

	hInst = hInstance;		// Store instance handle in our global variable
	// Initialize global strings
	LoadString(hInstance, IDC_ADOSAMPLE, szWindowClass, MAX_LOADSTRING);
	MyRegisterClass(hInstance, szWindowClass);

	LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
	hWnd = CreateWindow(szWindowClass, szTitle, WS_VISIBLE,
		CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

	if (!hWnd)
	{	
		return FALSE;
	}

	ShowWindow(hWnd, nCmdShow);
	UpdateWindow(hWnd);
	if (hwndCB)
		CommandBar_Show(hwndCB, TRUE);

	return TRUE;
}

//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND	- process the application menu
//  WM_PAINT	- Paint the main window
//  WM_DESTROY	- post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	HDC hdc;
	int wmId, wmEvent;
	PAINTSTRUCT ps;
	TCHAR szHello[MAX_LOADSTRING];

	switch (message) 
	{
		case WM_COMMAND:
			wmId    = LOWORD(wParam); 
			wmEvent = HIWORD(wParam); 
			// Parse the menu selections:
			switch (wmId)
			{
				case IDM_HELP_ABOUT:
				   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
				   break;
				case IDM_FILE_EXIT:
				   DestroyWindow(hWnd);
				   break;
				default:
				   return DefWindowProc(hWnd, message, wParam, lParam);
			}
			break;
		case WM_CREATE:
			hwndCB = CommandBar_Create(hInst, hWnd, 1);			
			CommandBar_InsertMenubar(hwndCB, hInst, IDM_MENU, 0);
			CommandBar_AddAdornments(hwndCB, 0, 0);
			break;
		case WM_PAINT:
			RECT rt;
			hdc = BeginPaint(hWnd, &ps);
			GetClientRect(hWnd, &rt);
			LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);
			DrawText(hdc, szHello, _tcslen(szHello), &rt, 
				DT_SINGLELINE | DT_VCENTER | DT_CENTER);
			EndPaint(hWnd, &ps);
			break;
		case WM_DESTROY:
			CommandBar_Destroy(hwndCB);
			PostQuitMessage(0);
			break;
		default:
			return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

// Mesage handler for the About box.
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	RECT rt, rt1;
	int DlgWidth, DlgHeight;	// dialog width and height in pixel units
	int NewPosX, NewPosY;

	switch (message)
	{
		case WM_INITDIALOG:
			// trying to center the About dialog
			if (GetWindowRect(hDlg, &rt1)) {
				GetClientRect(GetParent(hDlg), &rt);
				DlgWidth	= rt1.right - rt1.left;
				DlgHeight	= rt1.bottom - rt1.top ;
				NewPosX		= (rt.right - rt.left - DlgWidth)/2;
				NewPosY		= (rt.bottom - rt.top - DlgHeight)/2;
				
				// if the About box is larger than the physical screen 
				if (NewPosX < 0) NewPosX = 0;
				if (NewPosY < 0) NewPosY = 0;
				SetWindowPos(hDlg, 0, NewPosX, NewPosY,
					0, 0, SWP_NOZORDER | SWP_NOSIZE);
			}
			return TRUE;

		case WM_COMMAND:
			if ((LOWORD(wParam) == IDOK) || (LOWORD(wParam) == IDCANCEL))
			{
				EndDialog(hDlg, LOWORD(wParam));
				return TRUE;
			}
			break;
	}
    return FALSE;
}