A sample IE BHO for getting webbrowser's POST data in BeforeNavigate2 event.
Compiler: VC6
Install: regsvr32 full/path/to/liigobho.dll (need administrator privileges)
Uninstall: regsvr32 full/path/to/liigobho.dll (need administrator privileges)
The core code in file BhoApp.cpp list here:
STDMETHODIMP CBhoApp::Invoke(DISPID dispidMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS *pDispParams, VARIANT *pvarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
{
switch(dispidMember)
{
case DISPID_BEFORENAVIGATE2:
{
//liigo 2013年6月26日:
//there are 7 args in pDispParams->rgvarg[0] to pDispParams->rgvarg[6]
assert(pDispParams->cArgs == 7);
//Arg0: Cancel
VARIANTARG argCancel = pDispParams->rgvarg[0];
assert(argCancel.vt == (VT_BYREF|VT_BOOL));
//we can set VARIANT_TRUE to cancel the navigation
// *(argCancel.pboolVal) = VARIANT_TRUE;
//Arg1: Headers
VARIANTARG argHeaders = pDispParams->rgvarg[1];
assert(argHeaders.vt == (VT_BYREF|VT_VARIANT));
assert(argHeaders.pvarVal->vt == VT_BSTR);
BSTR bstrHeaders = argHeaders.pvarVal->bstrVal;
MessageBoxW(0, bstrHeaders, L"headers", MB_OK);
//Arg2: PostData
VARIANTARG argPostData = pDispParams->rgvarg[2];
assert(argPostData.vt == (VT_BYREF|VT_VARIANT));
assert(argPostData.pvarVal->vt == (VT_BYREF|VT_VARIANT));
if(argPostData.pvarVal->pvarVal->vt != VT_EMPTY)
{
assert(argPostData.pvarVal->pvarVal->vt == (VT_ARRAY|VT_UI1));
SAFEARRAY* pSafeArray = argPostData.pvarVal->pvarVal->parray;
assert(pSafeArray);
assert(pSafeArray->cDims == 1 && pSafeArray->cbElements == 1); //array of VT_UI1
unsigned int nPostDataSize = pSafeArray->rgsabound[0].cElements * pSafeArray->cbElements; //in bytes
void* pPostData = pSafeArray->pvData;
ShowDataMessage(pPostData, nPostDataSize, "post data binary");
MessageBoxA(0, (char*)pPostData, "post data string", MB_OK);
}
//Arg3: TargetFrameName
VARIANTARG argTargetFrameName = pDispParams->rgvarg[3];
assert(argTargetFrameName.vt == (VT_BYREF|VT_VARIANT));
assert(argTargetFrameName.pvarVal->vt == VT_BSTR);
BSTR bstrTargetFrameName = argTargetFrameName.pvarVal->bstrVal;
MessageBoxW(0, bstrTargetFrameName, L"TargetFrameName", MB_OK);
//Arg4: Flags
VARIANTARG argFlags = pDispParams->rgvarg[4];
assert(argFlags.vt == (VT_BYREF|VT_VARIANT));
assert(argFlags.pvarVal->vt == VT_I4);
LONG lFlags = argFlags.pvarVal->lVal;
//Arg5: Url
VARIANTARG argUrl = pDispParams->rgvarg[5];
assert(argUrl.vt == (VT_BYREF|VT_VARIANT));
assert(argUrl.pvarVal->vt == VT_BSTR);
BSTR bstrUrl = argUrl.pvarVal->bstrVal;
MessageBoxW(0, bstrUrl, L"URL", MB_OK);
//Arg6: WebBrowser
VARIANTARG argWebBrowser = pDispParams->rgvarg[6];
assert(argWebBrowser.vt == VT_DISPATCH);
IDispatch* pDispWebBrowser = argWebBrowser.pdispVal;
return S_OK;
}