能给的我都给了。调用DLL函数为何这么麻烦、？

[programCat]

我的程序是这样的:
在我的主窗口中动态装载DLL，得到DLL几个函数的指针。
通过dll的一个函数告诉dll接受消息的窗口句柄（我给的是主窗口视图类句柄）

然后将其中一个函数指针传递给主窗口下的模式对话框，调用这个函数，DLL将会自动发一个消息给窗口句柄代表的窗口（lParam指向我请求的数据）。
可是我调用了该函数，却始终收不到消息.（消息映射在主窗口视图类中）
接着我在主窗口下试着调用该函数，却能够收到。

这是为什么？
猜测原因：
1函数指针传递是否有错？我是直接把函数指针赋给对话框类的一个用来保存它的成元变量
2是否因为主窗口视图类句柄的特殊性。

各位大虾教我

[westaf]

模式对话框会中断主窗口的消息循环的，因为此时模式对话框使程序进入了自己的消息循环。
我猜想，如果你用PostMessage的话，模式对话框关闭之后主窗口还能收到消息的；如果用SendMessage，消息就丢失了。

如果一定要主窗口实时响应这个消息，那么必须用非模式对话框。

[Holly]

你的猜测1,2都不像！
你用什么发消息？SendMessage?PostMessage?

[Holly]

to westaf:
错，如果是用SendMessage才不会有问题的，SendMessage的运作是直接访问消息映射表，然后调用消息响应函数，根本没有消息队列问题！只有PostMessage才有此问题！

[坎坷的菜贩]

没道理啊，代码贴出来看看。

[westaf]

非常抱歉！

经过测试，在模式对话框中，无论是SendMessage还是PostMessage都不会有问题。

原以为在主消息循环中调用DoModal后，在DoModal返回之前，程序不会再回到主消息循环中。刚才调试才发现，即使是PostMessage，消息也能立刻到达主消息循环。原因是模式对话框消息循环接管了主消息循环，但如果他发现不是对话框的消息，它仍然会将消息Dispatch到主消息循环的。（此时是主消息循环函数的第二次进入）这也是为什么模式对话框显示时，主窗口仍能够进行重画的原因。

哎，原以为自己以“精通”消息循环了，谁之一到关键场合还是出错;-)

如此说来，programCat的问题并不是处在对话框上。不知各位大侠有何高见？

[programCat]

sorry,你们理解错误了，DLL不是我写的，消息是DLL发的，我只不过是调用DLL的某个函数，
之后DLL会去取远程机器上的数据，取回后dll发一个消息给我指定句柄的窗口。因此我并不知道
SendMessage?PostMessage?
而且如果消息由自己发的话，不管是SendMessage or PostMessage 都因该可以收到的。（我已试过）
由于dll肯定正确...还是帖代码


// testView.cpp : implementation of the CTestView class
//

#include "stdafx.h"
#include "test.h"

#include "testDoc.h"
#include "testView.h"

#include "MainFrm.h"

#include "dbf.h"
#include <math.h>

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CTestView

IMPLEMENT_DYNCREATE(CTestView, CView)

BEGIN_MESSAGE_MAP(CTestView, CView)
//{{AFX_MSG_MAP(CTestView)
ON_COMMAND(IDM_LOGON, OnLogon)
ON_COMMAND(IDM_DISCONNECT, OnDisconnect)
ON_COMMAND(IDM_XIADAN, OnXiadan)
ON_COMMAND(ID_TTTTTTTT, OnTttttttt)
//}}AFX_MSG_MAP
ON_MESSAGE(WM_XIADAN, OnXiadanNotify)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CTestView construction/destruction

CTestView::CTestView()
{
// TODO: add construction code here
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
m_IsConnected=false;
m_hIxiadan = NULL;
m_pPromptDlg = NULL;
m_pfnHxInit = NULL;
m_pfnTerminateTrade = NULL;
m_pfnConnect = NULL;
m_pfnExchangeData = NULL;
m_pMainDlg=NULL;
}

CTestView::~CTestView()
{
}

BOOL CTestView::PreCreateWindow(CREATESTRUCT& cs)
{
// TODO: Modify the Window class or styles here by modifying
// the CREATESTRUCT cs

return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CTestView drawing

void CTestView::OnDraw(CDC* pDC)
{
CTestDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
// TODO: add draw code for native data here
}

/////////////////////////////////////////////////////////////////////////////
// CTestView diagnostics

#ifdef _DEBUG
void CTestView::AssertValid() const
{
CView::AssertValid();
}

void CTestView::Dump(CDumpContext& dc) const
{
CView::Dump(dc);
}

CTestDoc* CTestView::GetDocument() // non-debug version is inline
{
ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CTestDoc)));
return (CTestDoc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// CTestView message handlers
LRESULT CTestView::OnXiadanNotify(WPARAM, LPARAM lParam)
{
CNI_General *pInfo = (CNI_General *)lParam;
switch (pInfo->m_nEvent)
{
case CEV_START_CONNECT:
{
if (m_pPromptDlg)
{
delete m_pPromptDlg;
}
m_pPromptDlg = new CDialStatusDlg(m_iReq.m_nId, (long *)&m_pPromptDlg, this);
CWnd *pWnd = &m_pPromptDlg->m_ctlStatus;//pDlg->GetDlgItem(IDC_STATUS);
pWnd->SetWindowText(_T("正在连接主站..."));
break;
}
case CEV_CONNECT_PROMPT:
{
MessageBox("Connect prompt");
if (m_pPromptDlg)
{
CNI_ConnectPrompt *pInfo2 = (CNI_ConnectPrompt *)pInfo;
CWnd *pWnd = &m_pPromptDlg->m_ctlStatus;//pDlg->GetDlgItem(IDC_STATUS);
pWnd->SetWindowText(pInfo2->m_pszPrompt);
}
break;
}
case CEV_CONNECT_FAIL:
{
CNI_ConnectFail *pInfo2 = (CNI_ConnectFail *)pInfo;
if (pInfo2->m_pszErrorText)
{
AfxMessageBox(pInfo2->m_pszErrorText);
}
else
{
AfxMessageBox(_T("连接主站失败！"));
}
if (m_pPromptDlg)
{
delete m_pPromptDlg;
m_pPromptDlg = NULL;
}
//m_lCommID = 0;
break;
}
case CEV_CONNECT_SUCC:
{
CWnd *pWnd = &m_pPromptDlg->m_ctlStatus;//pDlg->GetDlgItem(IDC_STATUS);
pWnd->SetWindowText(_T("正在验证用户身份..."));
m_pPromptDlg->m_nStep = 2;
break;
}
case CEV_DISCONNECTED:
{
//m_lCommID = 0;
ReportMessage(_T("连接断开"));
break;
}
case CEV_RECEIVE_DATA:
{
CNI_ReceiveData *pInfo2 = (CNI_ReceiveData *)pInfo;
if (m_pPromptDlg)
{
float fTransmited = (float)pInfo2->m_lDataTransmited / pInfo2->m_lDataTotal;
if (fabs(fTransmited - m_pPromptDlg->m_fTransmited) >= 0.1)
{
m_pPromptDlg->m_fTransmited = fTransmited;
CRect rect;
m_pPromptDlg->GetDlgItem(IDC_INDICATOR)->GetWindowRect(&rect);
m_pPromptDlg->ScreenToClient(&rect);
m_pPromptDlg->InvalidateRect(&rect);
m_pPromptDlg->UpdateWindow();
}
}
if (pInfo2->m_nStatus == CLX_TS_END)
{
if (m_pPromptDlg)
{
//delete m_pPromptDlg;
//m_pPromptDlg = NULL;
}
IXiaDanReply *pHead = (IXiaDanReply *)pInfo2->m_pszData;
if(pHead->m_nId == m_iReq.m_nId)
{
//Do XD
OnReceiveData((char *)pInfo2->m_pszData, pInfo2->m_lDataTransmited);
}
}
break;
}
case CEV_IDLE:
{
break;
}
}

return 0;
}


void CTestView::OnReceiveData(char *pszBuffer, long cbBuffer)
{
if(pszBuffer == NULL || cbBuffer <= 0)
{
return;
}

IXiaDanReply *pPacket = (IXiaDanReply *)pszBuffer;
pPacket->m_nType &= ~XT_PLAINTEXT;

CString strTemp;
if (pPacket->m_nReturnCode != XD_SECCESS)
{
strTemp = pPacket->m_szReturnText;
}
else
{
switch(pPacket->m_nType)
{
case XT_SYS_LOGIN:
{
if (m_pPromptDlg)
{
delete m_pPromptDlg;
m_pPromptDlg = NULL;
}
strTemp = _T("登录成功");
break;
}
case XT_CHECK_ACCOUNT: //校验股东
{
CString strName = pPacket->m_szGDXM;
strTemp.Format(_T("校验股东成功，股东姓名：%s"), strName);
//m_iReq.m_nType = XT_NEW_QU_ZZC; //请求类型

//hxExchangeData(0, &m_iReq, sizeof(m_iReq), NULL, 0, NULL);

//CWnd* pWnd = GetDlgItem(IDC_TEST);

//PostMessage(WM_COMMAND, MAKELONG(IDC_TEST, BN_CLICKED), (LPARAM)pWnd->m_hWnd);
break;
}

case XT_CHG_PWD: //改变密码
{
strTemp = _T("改变交易密码成功");
break;
}

case XT_WEITUO_MAIRU: //委托买入
{
IXDWeiTuoInfo* pWeituo = (IXDWeiTuoInfo*)pPacket;
CString strHt = pWeituo->m_szHTBH;
strTemp.Format(_T("委托买入成功提交，合同编号：%s"), strHt);
break;
}
case XT_WEITUO_MAICHU: //委托卖出
{
IXDWeiTuoInfo* pWeituo = (IXDWeiTuoInfo*)pPacket;
CString strHt = pWeituo->m_szHTBH;
strTemp.Format(_T("委托卖出成功提交，合同编号：%s"), strHt);
break;
}

case XT_ZHUANZHANG_TOQUANSHANG: //银行转帐: 至券商
{
strTemp = _T("银行转帐: 至券商成功提交");
break;
}
case XT_ZHUANZHANG_TOBANK: //银行转帐: 至银行
{
strTemp = _T("银行转帐: 至银行成功提交");
break;
}

case XT_CHG_TONGXUN: //修改通讯密码
{
strTemp = _T("改变通讯密码成功");
break;
}
case XT_WEITUO_ZHUANGU: //委托转股
case XT_WEITUO_HUISHOU: //委托回售
{
break;
}

case XT_QU_ZIJINYUE: //查询资金余额
{
IXDZiJinYuEInfo* pYuE = (IXDZiJinYuEInfo*)pPacket;
strTemp.Format(_T("查询资金余额成功，可用余额：%.2lf"), pYuE->m_fKYYE);
break;
}
case XT_QU_STOCKINFO: //股票实时行情
{
IXDStockInfo* pStock = (IXDStockInfo*)pPacket;
float newPrice = (float)pStock->m_fNewPrice;
double buy1=(double)*(pStock->m_fBuyPrice);
double buy2=(double)*(pStock->m_fBuyPrice+1);
double buy3=(double)*(pStock->m_fBuyPrice+2);
double sell1=(double)*(pStock->m_fBuyPrice+3);
double sell2=(double)*(pStock->m_fBuyPrice+4);
double sell3=(double)*(pStock->m_fBuyPrice+5);
long bn1=(long)*(pStock->m_lBuyCount1);
long bn2=(long)*(pStock->m_lBuyCount1+1);
long bn3=(long)*(pStock->m_lBuyCount1+2);
long sn1=(long)*(pStock->m_lBuyCount1+3);
long sn2=(long)*(pStock->m_lBuyCount1+4);
long sn3=(long)*(pStock->m_lBuyCount1+5);
CString s1,s2,s3,s4,s5,s6,s,n1,n2,n3,n4,n5,n6;
s.Format(_T("%f"), newPrice);
s1.Format("%f",buy1); n1.Format("%d",bn1);
s2.Format("%f",buy2); n2.Format("%d",bn2);
s3.Format("%f",buy3); n3.Format("%d",bn3);
s4.Format("%f",sell1); n4.Format("%d",sn1);
s5.Format("%f",sell2); n5.Format("%d",sn2);
s6.Format("%f",sell3); n6.Format("%d",sn3);
// pStock->
if(m_pMainDlg!=NULL)
if((m_pMainDlg->m_pMmwtDlg)!=NULL)
{
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_NEWPRICE)->SetWindowText(s);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BUY1)->SetWindowText(s1);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BUY2)->SetWindowText(s2);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BUY3)->SetWindowText(s3);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SELL1)->SetWindowText(s4);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SELL2)->SetWindowText(s5);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SELL3)->SetWindowText(s6);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BN1)->SetWindowText(n1);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BN2)->SetWindowText(n2);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_BN3)->SetWindowText(n3);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SN1)->SetWindowText(n4);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SN2)->SetWindowText(n5);
m_pMainDlg->m_pMmwtDlg->GetDlgItem(IDC_EDIT_SN3)->SetWindowText(n6);
}
break;
}

case XT_NEW_QU_GUPIAO: //查询股票余额
case XT_NEW_QU_CHENGJIAO: //查询成交
case XT_NEW_QU_WEITUO: //查询委托
case XT_NEW_QU_BANK: //查询银行
case XT_NEW_QU_ACCOUNT: //查询帐户
case XT_NEW_QU_DZD: //查询对帐单
case XT_NEW_QU_JGD: //查询交割单
case XT_NEW_QU_ZJMX: //查询资金明细
case XT_NEW_QU_ZZC:
{
IXDQueryInfo* pQuery = (IXDQueryInfo*)pPacket;
strTemp.Format(_T("查询成功，数据总长度：%d"), pQuery->m_lSize);
DbFileFlag* pDbf = (DbFileFlag*)(pQuery->m_szBuffer);
break;
}
}
}
if(!strTemp.IsEmpty())
{
ReportMessage(strTemp);
}
}

void CTestView::ReportMessage(const TCHAR *pszMessage)
{
if (m_pPromptDlg)
{
delete m_pPromptDlg;
}
m_pPromptDlg = new CDialStatusDlg(m_iReq.m_nId, (long *)&m_pPromptDlg, this);
m_pPromptDlg->m_nFlag = 2;
m_pPromptDlg->GetDlgItem(IDCANCEL)->SetWindowText(_T("确定"));
m_pPromptDlg->SetWindowText(_T("提示"));
CWnd *pWnd = &m_pPromptDlg->m_ctlStatus;//pDlg->GetDlgItem(IDC_STATUS);
pWnd->SetWindowText(pszMessage);
}

void CTestView::LoadXiadan()
{
if(m_hIxiadan != NULL)
{
return;
}
HXTRADEVERSIONINFO hxVersionInfo;
CString strProfile = AfxGetApp()->m_pszProfileName;
m_hIxiadan = LoadLibrary("ixiadan.dll");
if (m_hIxiadan)
{
FARPROC *pAddr;
pAddr = (FARPROC *)&m_pfnHxInit;
*pAddr = GetProcAddress(m_hIxiadan, "hxInit");
pAddr = (FARPROC *)&m_pfnTerminateTrade;
*pAddr = GetProcAddress(m_hIxiadan, "hxTerminateTrade");
pAddr = (FARPROC *)&m_pfnConnect;
*pAddr = GetProcAddress(m_hIxiadan, "hxConnect");
pAddr = (FARPROC *)&m_pfnExchangeData;
*pAddr = GetProcAddress(m_hIxiadan, "hxExchangeData");

if(m_pfnHxInit)
{
if((*m_pfnHxInit)(&hxVersionInfo, strProfile) && m_pfnConnect)
{
IXDConnectStruct iConnect;
iConnect.m_pszIP = _T("61.153.3.4");
iConnect.m_nPort = 8003;
CMainFrame *pWnd=(CMainFrame *)::AfxGetMainWnd();

m_iReq.m_nId = (*m_pfnConnect)(pWnd->GetActiveView()->m_hWnd, WM_XIADAN, &iConnect);
}
}
}
}
void CTestView::FreeXiadan()
{
if(m_hIxiadan == NULL)
{
return;
}

if(m_pfnTerminateTrade)
{
//(*m_pfnTerminateTrade)();
}
FreeLibrary(m_hIxiadan);
/*
m_hIxiadan = NULL;
m_pfnHxInit = NULL;
m_pfnTerminateTrade = NULL;
m_pfnConnect = NULL;
m_pfnExchangeData = NULL;
*/
}

void CTestView::OnLogon()
{
// TODO: Add your command handler code here
LoadXiadan();
m_iReq.m_nType=XT_CHECK_ACCOUNT;
strcpy(m_iReq.m_strPwd,"999999");
strcpy(m_iReq.m_strPwd2,"777777");
strcpy(m_iReq.m_strAccount,"10002752");
m_iReq.m_cSetCode=0+'0';
long lRet;
if(m_pfnExchangeData)
{
lRet= (*m_pfnExchangeData)(0, &m_iReq, sizeof(m_iReq), NULL, 0, NULL);
}
if(lRet)
m_IsConnected=true;

}

void CTestView::OnDisconnect()
{
// TODO: Add your command handler code here
if(m_IsConnected)
{
FreeXiadan();
m_IsConnected=false;
}
}

void CTestView::OnXiadan()
{
// TODO: Add your command handler code here
CMainDlg dlg;
dlg.m_pfnExchangeData=m_pfnExchangeData;
m_pMainDlg=&dlg;
dlg.DoModal();
}

void CTestView::OnTttttttt()
{
// TODO: Add your command handler code here
m_iReq.m_nType=XT_QU_STOCKINFO;
strcpy(m_iReq.m_strPwd,"999999");
strcpy(m_iReq.m_strPwd2,"777777");
strcpy(m_iReq.m_strAccount,"10002752");
m_iReq.m_cSetCode=0+'0';
strcpy(m_iReq.m_szStockCode,"600001");
long lRet;
if(m_pfnExchangeData)
{
lRet= (*m_pfnExchangeData)(0, &m_iReq, sizeof(m_iReq), NULL, 0, NULL);
}
}



void CTestView::OnInitialUpdate()
{
CView::OnInitialUpdate();

// TODO: Add your specialized code here and/or call the base class

}





// MmwtDlg.cpp : implementation file
//

#include "stdafx.h"
#include "test.h"
#include "MmwtDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CMmwtDlg dialog


CMmwtDlg::CMmwtDlg(CWnd* pParent /*=NULL*/)
: CDialog(CMmwtDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CMmwtDlg)
m_csStockName = _T("");
//}}AFX_DATA_INIT
}


void CMmwtDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CMmwtDlg)
DDX_CBString(pDX, IDC_LIST_STOCKCODE, m_csStockName);
//}}AFX_DATA_MAP
}


BEGIN_MESSAGE_MAP(CMmwtDlg, CDialog)
//{{AFX_MSG_MAP(CMmwtDlg)
ON_CBN_EDITCHANGE(IDC_LIST_STOCKCODE, OnEditchangeListStockcode)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMmwtDlg message handlers



void CMmwtDlg::OnEditchangeListStockcode()
{
// TODO: Add your control notification handler code here
m_iReq.m_nType=XT_QU_STOCKINFO;
strcpy(m_iReq.m_strPwd,"999999");
strcpy(m_iReq.m_strPwd2,"777777");
strcpy(m_iReq.m_strAccount,"10002752");
m_iReq.m_cSetCode=0+'0';
strcpy(m_iReq.m_szStockCode,"600001");
long lRet;
if(m_pfnExchangeData)
{
lRet= (*m_pfnExchangeData)(0, &m_iReq, sizeof(m_iReq), NULL, 0, NULL);
}

}



我贴了两个cpp，其中CTestView包含了消息相应函数，CMmwtDlg是对话框类，OnEditchangeListStockcode（）是对话框里一个控件的事件，m_pfnExchangeData是传过来的
函数指针，他与CTestView中的m_pfnExchangeData所指的相同。

[shenxinyu]

你指定的窗口句柄在那呢，我怎么没看见？

[rjren]

how can the function (*m_pfnExchangeData)
know which window it should post message to?

[Holly]

问programCat:
1.你的程序是单文档，是吗?
2.你怎样确定
(*m_pfnExchangeData)(0, &m_iReq, sizeof(m_iReq), NULL, 0, NULL);
会发消息给
(*m_pfnConnect)(pWnd->GetActiveView()->m_hWnd, WM_XIADAN, &iConnect);
中传递的窗口句柄中！

[programCat]

非常抱歉。
惭愧惭愧。
不好意思，浪费了大家的时间，由于我的不慎在调用(*m_pfnExchangeData)时，在参数中少给了
数据，导致dll并没有发出消息，自然主窗口收不到了，而在主窗口调用时由于前面已经赋过值，
所以收到了消息。

但也不是没有收获，明白了在模式对话框并不会阻塞主窗口的消息，只是不接受由程序用户发出的消息，程序发出的仍可以收到。

感谢各位，人人有分。