在MFC对话框中使用Google地图(续)
在完成了基本功能以后，接下来就可以实现输入经纬度在地图中显示地点的功能了。这里就要用到VC和JavaScript的混合编程了。
如何在VC中调用JavaScript的函数，以下两个分别是CWebPage类的.h和.cpp文件：
// WebPage.h: interface for the CWebPage class. // ////////////////////////////////////////////////////////////////////// #if !defined(AFX_WEBPAGE_H__AEBD50B8_EE66_40AB_8B92_C4EECB9BCD22__INCLUDED_) #define AFX_WEBPAGE_H__AEBD50B8_EE66_40AB_8B92_C4EECB9BCD22__INCLUDED_ #if _MSC_VER > 1000 #pragma once #endif // _MSC_VER > 1000 #include <atlbase.h> #include <Mshtml.h> class CWebPage { public: CWebPage(); virtual ~CWebPage(); bool SetDocument(IDispatch* pDisp); LPDISPATCH GetHtmlDocument() const; const CString GetLastError() const; bool GetJScript(CComPtr<IDispatch>& spDisp); bool GetJScripts(CComPtr<IHTMLElementCollection>& spColl); CString ScanJScript(CString& strAText, CStringArray& args); bool CallJScript(const CString strFunc,CComVariant* pVarResult = NULL); bool CallJScript(const CString strFunc,const CString strArg1,CComVariant* pVarResult = NULL); bool CallJScript(const CString strFunc,const CString strArg1,const CString strArg2,CComVariant* pVarResult = NULL); bool CallJScript(const CString strFunc,const CString strArg1,const CString strArg2,const CString strArg3,CComVariant* pVarResult = NULL); bool CallJScript(const CString strFunc,const CStringArray& paramArray,CComVariant* pVarResult = NULL); protected: void ShowError(LPCSTR lpszText); protected: CComPtr<IHTMLDocument2> m_spDoc; CString m_strError; }; inline void CWebPage::ShowError(LPCSTR lpszText) { m_strError = "JSCall Error:\n" + CString(lpszText); } inline const CString CWebPage::GetLastError() const { return m_strError; } inline LPDISPATCH CWebPage::GetHtmlDocument() const { return m_spDoc; } CString GetNextToken(CString& strSrc, const CString strDelim,bool bTrim = false, bool bFindOneOf = true); #endif // !defined(AFX_WEBPAGE_H__AEBD50B8_EE66_40AB_8B92_C4EECB9BCD22__INCLUDED_)
///////////////////////////////////////////////////////////////// // By Eugene Khodakovsky // // April,2002 // // Eugene@cpplab.com // // Last Update: April, 2002 // ///////////////////////////////////////////////////////////////// //////// WebPage.cpp #include "stdafx.h" //#include "JSCall.h" #include "WebPage.h" #ifdef _DEBUG #undef THIS_FILE static char THIS_FILE[]=__FILE__; #define new DEBUG_NEW #endif #define CHECK_POINTER(p)\ ATLASSERT(p != NULL);\ if(p == NULL)\ {\ ShowError("NULL pointer");\ return false;\ } const CString GetSystemErrorMessage(DWORD dwError) { CString strError; LPTSTR lpBuffer; if(!FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_SYS_DEFAULT), (LPTSTR) &lpBuffer, 0, NULL)) { strError = "FormatMessage Netive Error" ; } else { strError = lpBuffer; LocalFree(lpBuffer); } return strError; } CString GetNextToken(CString& strSrc, const CString strDelim,bool bTrim, bool bFindOneOf) { CString strToken; int idx = bFindOneOf? strSrc.FindOneOf(strDelim) : strSrc.Find(strDelim); if(idx != -1) { strToken = strSrc.Left(idx); strSrc = strSrc.Right(strSrc.GetLength() - (idx + 1) ); } else { strToken = strSrc; strSrc.Empty(); } if(bTrim) { strToken.TrimLeft(); strToken.TrimRight(); } return strToken; } ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// CWebPage::CWebPage() { } CWebPage::~CWebPage() { } bool CWebPage::SetDocument(IDispatch* pDisp) { CHECK_POINTER(pDisp); m_spDoc = NULL; CComPtr<IDispatch> spDisp = pDisp; HRESULT hr = spDisp->QueryInterface(IID_IHTMLDocument2,(void**)&m_spDoc); if(FAILED(hr)) { ShowError("Failed to get HTML document COM object"); return false; } return true; } bool CWebPage::GetJScript(CComPtr<IDispatch>& spDisp) { CHECK_POINTER(m_spDoc); HRESULT hr = m_spDoc->get_Script(&spDisp); ATLASSERT(SUCCEEDED(hr)); return SUCCEEDED(hr); } bool CWebPage::GetJScripts(CComPtr<IHTMLElementCollection>& spColl) { CHECK_POINTER(m_spDoc); HRESULT hr = m_spDoc->get_scripts(&spColl); ATLASSERT(SUCCEEDED(hr)); return SUCCEEDED(hr); } bool CWebPage::CallJScript(const CString strFunc,CComVariant* pVarResult) { CStringArray paramArray; return CallJScript(strFunc,paramArray,pVarResult); } bool CWebPage::CallJScript(const CString strFunc,const CString strArg1,CComVariant* pVarResult) { CStringArray paramArray; paramArray.Add(strArg1); return CallJScript(strFunc,paramArray,pVarResult); } bool CWebPage::CallJScript(const CString strFunc,const CString strArg1,const CString strArg2,CComVariant* pVarResult) { CStringArray paramArray; paramArray.Add(strArg1); paramArray.Add(strArg2); return CallJScript(strFunc,paramArray,pVarResult); } bool CWebPage::CallJScript(const CString strFunc,const CString strArg1,const CString strArg2,const CString strArg3,CComVariant* pVarResult) { CStringArray paramArray; paramArray.Add(strArg1); paramArray.Add(strArg2); paramArray.Add(strArg3); return CallJScript(strFunc,paramArray,pVarResult); } bool CWebPage::CallJScript(const CString strFunc, const CStringArray& paramArray,CComVariant* pVarResult) { CComPtr<IDispatch> spScript; if(!GetJScript(spScript)) { ShowError("Cannot GetScript"); return false; } CComBSTR bstrMember(strFunc); DISPID dispid = NULL; HRESULT hr = spScript->GetIDsOfNames(IID_NULL,&bstrMember,1, LOCALE_SYSTEM_DEFAULT,&dispid); if(FAILED(hr)) { ShowError(GetSystemErrorMessage(hr)); return false; } const int arraySize = paramArray.GetSize(); DISPPARAMS dispparams; memset(&dispparams, 0, sizeof dispparams); dispparams.cArgs = arraySize; dispparams.rgvarg = new VARIANT[dispparams.cArgs]; for( int i = 0; i < arraySize; i++) { CComBSTR bstr = paramArray.GetAt(arraySize - 1 - i); // back reading bstr.CopyTo(&dispparams.rgvarg[i].bstrVal); dispparams.rgvarg[i].vt = VT_BSTR; } dispparams.cNamedArgs = 0; EXCEPINFO excepInfo; memset(&excepInfo, 0, sizeof excepInfo); CComVariant vaResult; UINT nArgErr = (UINT)-1; // initialize to invalid arg hr = spScript->Invoke(dispid,IID_NULL,0, DISPATCH_METHOD,&dispparams,&vaResult,&excepInfo,&nArgErr); delete [] dispparams.rgvarg; if(FAILED(hr)) { ShowError(GetSystemErrorMessage(hr)); return false; } if(pVarResult) { *pVarResult = vaResult; } return true; } // returned java script function name, input string is truncating CString CWebPage::ScanJScript(CString& strAText, CStringArray& args) { args.RemoveAll(); CString strDelim(" \n\r\t"),strSrc(strAText); bool bFound = false; while(!strSrc.IsEmpty()) { CString strStart = GetNextToken(strSrc,strDelim); if(strStart == "function") { bFound = true; break; } if(strStart == "/*") { // Skip comments while(!strSrc.IsEmpty()) { CString strStop = GetNextToken(strSrc,strDelim); if(strStop == "*/") { break; } } } } if(!bFound) return ""; CString strFunc = GetNextToken(strSrc,"(",true); CString strArgs = GetNextToken(strSrc,")",true); // Parse arguments CString strArg; while(!(strArg = GetNextToken(strArgs,",")).IsEmpty()) args.Add(strArg); strAText= strSrc; return strFunc; }
在对话框中添加测试调用JS函数按钮，在XXXDlg.cpp中该按钮单击消息函数中加入代码如下：
CWebPage web; web.SetDocument(m_webBrowser.GetDocument()); web.CallJScript("jsfunctiontest");//调用JS中的jsfunctiontest函数
然后编译运行，点击按钮就会有一个名为来自网页消息弹出框，测试成功，实现VC和JavaScript的混合编程。
在对话框中添加两个编辑框和一个按钮，在编辑框中输入经度和纬度，点击按钮谷歌地图跳转到相应的地点。
按钮的点击消息响应函数中代码如下：
UpdateData(TRUE);//将控件上的值传回变量 CWebPage web; web.SetDocument(m_webBrowser.GetDocument()); //调用JS中的函数TansTo()，并传递2个参数(纬度，经度) web.CallJScript("TansTo", m_latitude, m_longitude);
好了，以上完成了输入经纬度在地图中显示地点的功能。
接下来就可以仔细的分析代码了。
