account.cpp

本程序是利用com原理开发的一个ATM机与银行之间的分布式应用

// Account.cpp : Implementation of CAccount
#include "stdafx.h"
#include "Bank.h"
#include "Account.h"

/////////////////////////////////////////////////////////////////////////////
// CAccount

/*
STDMETHODIMP CAccount::Login(BSTR AccountID, BSTR Pswd, BOOL *pIsValid)
{
	// TODO: Add your implementation code here

	return S_OK;
}

STDMETHODIMP CAccount::GetCurrentFund(BSTR AccountID, float *pCurFund)
{
	// TODO: Add your implementation code here

	return S_OK;
}

STDMETHODIMP CAccount::Deposit(BSTR AccountID, float saving, float *pCurFund)
{
	// TODO: Add your implementation code here

	return S_OK;
}

STDMETHODIMP CAccount::WithDraw(BSTR AccountID, float drawing, float *pCurFund)
{
	// TODO: Add your implementation code here

	return S_OK;
}
*/

BOOL CAccount::ConnectDBSource(/*BSTR AccountID,BSTR Pswd*/)
{
	//----连接数据源---------------
	try	
	{
		CoInitialize(NULL);                                    // 初始化COM.
		m_pConnection.CreateInstance(__uuidof(Connection));    //实例化_ConnectionPtr对象，并调用Open方法
		m_pConnection->Open("DSN=BankAccount;",	_bstr_t(""), _bstr_t(""),adModeUnknown  );    
		if (NULL== m_pConnection)	 
		{
   	        MessageBox(NULL,_T("连接数据源出错!"),_T("ERROR"),MB_OK);
			return FALSE;
		}
		else
			return TRUE;
	}
	catch(_com_error  &e)
	{
		_bstr_t bstrError(e.ErrorMessage());
        MessageBox(NULL,bstrError,_T("ERROR"),MB_OK);
	}
	catch (...)	
	{	
        MessageBox(NULL,_T("未知错误!"),_T("ERROR"),MB_OK);
	}
}

//==接口函数=================================================================
STDMETHODIMP CAccount::Login(BSTR AccountID, BSTR Pswd, BOOL *pIsValid)
{
    if(ConnectDBSource())
	{
		//---创建命令----------------------------------------
		pCommand.CreateInstance (__uuidof (Command));
		pCommand->ActiveConnection = m_pConnection; 

		_bstr_t  strSQL ="Select * From Account Where AccountID Like '";
		strSQL+=AccountID;
		strSQL+="' And Password Like'";
		strSQL+=Pswd;
		strSQL+="'"; 
		pCommand->CommandText = strSQL ;   //拼写查询字串

		pRecordset.CreateInstance (__uuidof (Recordset));
		pRecordset->CursorLocation = adUseClient;
		pRecordset->Open((IDispatch *) pCommand, vtMissing, adOpenStatic, adLockOptimistic, adCmdUnknown);
		//----------------------
		if(pRecordset->adoEOF)        //若未找到则返回FALSE
			 *pIsValid = FALSE;
		else                          //若找到则返回TRUE
			*pIsValid = TRUE;
		CoUninitialize();  
	}
	return S_OK;
}
//==获取当前存款余额===========================================
STDMETHODIMP CAccount::GetCurrentFund(BSTR AccountID, float *pCurFund)
{
    if(ConnectDBSource())
	{
		//--创建命令--------------------
		pCommand.CreateInstance (__uuidof (Command));
		pCommand->ActiveConnection = m_pConnection; 
		_bstr_t  strSQL ="Select * From Account Where AccountID Like '";
		strSQL+=AccountID;
		strSQL+="'";
		pCommand->CommandText = strSQL ;   //拼写查询字串
		//--获取数据集--------------------
		
		pRecordset.CreateInstance (__uuidof (Recordset));
		pRecordset->CursorLocation = adUseClient;
		pRecordset->Open((IDispatch *) pCommand, vtMissing, adOpenStatic, adLockOptimistic, adCmdUnknown);
		if(!pRecordset->adoEOF)       
		{
			FieldsPtr pFields=pRecordset->Fields;
			FieldPtr pValue = pFields->GetItem("CurrentFund");  //取CurrentFund字段的值 
			*pCurFund =pValue->Value; 
		}  
		CoUninitialize();  
	}
	return S_OK;
}

//==存钱===================================================== 
STDMETHODIMP CAccount::Deposit(BSTR AccountID, float saving, float *pCurFund)
{
    if(ConnectDBSource())
	{
		//--创建命令--------------------
		pCommand.CreateInstance (__uuidof (Command));
		pCommand->ActiveConnection = m_pConnection; 
		_bstr_t  strSQL ="Select * From Account Where AccountID Like '";
		strSQL+=AccountID;
		strSQL+="'";
		pCommand->CommandText = strSQL ;   //拼写查询字串
		//--获取数据集--------------------
		pRecordset.CreateInstance (__uuidof (Recordset));
		pRecordset->CursorLocation = adUseClient;
		pRecordset->Open((IDispatch *) pCommand, vtMissing, adOpenStatic, adLockOptimistic, adCmdUnknown);
		if(!pRecordset->adoEOF)       
		{
			FieldsPtr pFields=pRecordset->Fields;
			FieldPtr pValue = pFields->GetItem("CurrentFund");  //取CurrentFund字段的值 
			float curFund = pValue->Value;
			curFund= curFund+saving;
		    float temp = curFund;
			pCurFund = &temp; 
			//--更新纪录-------------
			char  buffer[30]; 
			_gcvt( curFund, 30, buffer );

			_variant_t vColumn,vValue;
			vColumn.SetString("CurrentFund");
			vValue.SetString(buffer);
			pRecordset->Update(vColumn,vValue);
		}  
		CoUninitialize();  
	}
	return S_OK;	
}

//==取钱===================================================== 
STDMETHODIMP CAccount::WithDraw(BSTR AccountID, float drawing, float *pCurFund)
{
	if(ConnectDBSource())
	{
		//--创建命令--------------------
		pCommand.CreateInstance (__uuidof (Command));
		pCommand->ActiveConnection = m_pConnection; 
		_bstr_t  strSQL ="Select * From Account Where AccountID Like '";
		strSQL+=AccountID;
		strSQL+="'";					   //!!!
		pCommand->CommandText = strSQL ;   //拼写查询字串
		//--获取数据集--------------------
		pRecordset.CreateInstance (__uuidof (Recordset));
		pRecordset->CursorLocation = adUseClient;
		pRecordset->Open((IDispatch *) pCommand, vtMissing, adOpenStatic, adLockOptimistic, adCmdUnknown);  //勿将adLockOptimistic设为adLockBatchOptimistic
		if(!pRecordset->adoEOF)       
		{

			FieldsPtr pFields=pRecordset->Fields;
			FieldPtr pValue = pFields->GetItem("CurrentFund");  //取CurrentFund字段的值 
			float curFund = pValue->Value;
			curFund -= drawing;
		    float temp = curFund;
			pCurFund = &temp;             //返回值
			//--更新纪录-------------
			char  buffer[30]; 
			_gcvt( curFund, 30, buffer );

			_variant_t vColumn,vValue;
			vColumn.SetString("CurrentFund");
			vValue.SetString(buffer);
			pRecordset->Update(vColumn,vValue);
		}
		CoUninitialize();  
	}
	return S_OK;
}