I am using the iefram.dll webbrowser control. I can navigate to different url with the IWebBrowser2.Navigate2 function. Even the "about:blank" is working. Now I want to write to the document from memory.
With the "about:blank" document I retrieve the document object with IWebBrowser2.Document function.
Now my problem starts.
MSDN say that IHTMLDocument.Write parameter should be a safe array.
pHtmlText is a BSTR
invoke SafeArrayCreateVector,VT_VARIANT,0,1
mov pSafeArray,eax
invoke SafeArrayAccessData,pSafeArray,addr pData
mov ebx,pData
mov word ptr [ebx].VARIANT.vt,VT_BSTR
mov eax,pHtmlText
mov dword ptr [ebx].VARIANT.bstrVal,eax
invoke SafeArrayUnaccessData,pSafeArray
invoke VariantInit,addr var1
mov var1.vt,VT_SAFEARRAY
mov eax,pSafeArray
mov var1.parray,eax
IHTMLDocument.Write(addr var1)
This will be a blank page totally empty not even <html></html>. Changing the parameter to pSafeArray result in "NULL" on the page. As I can see the safe array has no NULL string.
Now I use the BSTR as parameter
invoke VariantInit,addr var1
mov var1.vt,VT_BSTR
mov eax,pHtmlText
mov var1.bstrVal,eax
IHTMLDocument.Write(addr var1)
This will aleast give a result. If the html code i a short text strings it works well but if it is a longer htmlcode the text string is truncated and it is also in some extent not written as I wrote it.
Any idea how to solve this problem
How defined pHtmlText variable?
BSTR datatype uses a DWORD with a length of the string, which lies 4 bytes above the pointer to the string.
I.e., proper pre-initialized BSTR should look like:
.data
dd sizeof pHtmlText
pHtmlText dw "<","h","t","m","l" ... and so on ... ; dw is because BSTR is usually Unicode string
pHtmlText is a pointer to a unicode string preseeded whith the length of the string, i.e. a BSTR string. I'm sure of that.
the method write() expects the type SAFEARRAY* whereas your code passes a VARIANTARG* -> you might try it with using pSafeArray instead.
invoke SafeArrayCreateVector,VT_VARIANT,0,1
mov pSafeArray,eax
mov ebx,eax
mov word ptr [ebx].SAFEARRAY.fFeatures,100h ;FADF_BSTR
invoke SafeArrayAccessData,pSafeArray,addr pData
mov ebx,pData
mov word ptr [ebx].VARIANT.vt,VT_BSTR
mov eax,pHtmlText
mov dword ptr [ebx].VARIANT.bstrVal,eax
invoke SafeArrayUnaccessData,pSafeArray
lea edi,dp ;dispparams sturcture
mov eax,pSafeArray
mov dword ptr [edi].DISPPARAMS.rgvarg,eax
mov dispidNamed,DISPID_VALUE
lea eax,dispidNamed ;default handle!
mov dword ptr [edi].DISPPARAMS.rgdispidNamedArgs,eax
mov dword ptr [edi].DISPPARAMS.cArgs,1
mov dword ptr [edi].DISPPARAMS.cNamedArgs,0
invoke VariantInit,addr RetVal
push 0
push 0
lea eax,RetValue
push eax
lea eax,dp
push eax
push DISPATCH_METHOD
push lcid
push offset NullCLSCID
push memid
mov eax,ppHtmlDocument
mov edx,dword ptr [eax]
push ppHtmlDocument
add edx,offs ;offs = IDispatch.Invoke
call dword ptr [edx]
No error in execution. Result page showing "null" with page code = "null" nothing more.
If I make a temporary file and navigate to this file correct page is visible.
My project is to calculate the sun's position at any selected time and at any selected
location on earth. I use Google maps and Google timezone api to select locations. There
are some drawings with Gdip flat apis. The ClientSite of the webbrowser control was a
tricky item to solve. I have written more clientsite methods than is used i this project.
For those who are interested the application can be downloaded and you can read the code
here (http://minor28.divdev.se/ (http://minor28.divdev.se/))
How hard I tried I could not get the Write and Close methods to write to the about:blank
document. By contrast, I could create a temporary file to navigate to. The file could be
deleted after the page load was completed. A solution without creating a temporary file
was to stream text using the interface IPersistStreamInit. This became the solution.
;Implement IPersistStreamInit on the document to init stream persistance
invoke Set_Interface,ppIHTMLDocument2,WSTR("{7FD52380-4E07-101B-AE2D-08002B2EC713}"),
1,addr ppIPersistStreamInit
;Create the stream from resource html code
invoke FindResource,hInstance,RES_MAP,RT_RCDATA
.if eax
mov hResinfo,eax
invoke LoadResource,hInstance,hResinfo
.if eax
push esi ;preserve
mov esi,eax
push eax
invoke SizeofResource,hInstance,hResinfo
invoke GlobalAlloc,GMEM_MOVEABLE or GMEM_NODISCARD,eax
.if eax
push edi ;preserve
mov hMem,eax
invoke GlobalLock,eax
mov edi,eax
push edi
xor ecx,ecx
.while byte ptr [esi]!=0
movsb
inc ecx
.endw
pop edi
invoke CreateStreamOnHGlobal,edi,TRUE,addr ppIStream
.if eax==S_OK
;Load the stream
invoke RunInterfaceMethod,ppIPersistStreamInit,IPersistStreamInit.Load,
1,ppIStream
.if eax==S_OK
;Make the browser connectable
invoke AdviseEvent,ppIWebBrowser2,offset DIID_DWebBrowserEvents2
invoke Release_Object,ppIPersistStreamInit
.endif
invoke Release_Object,ppIStream
.endif
invoke GlobalFree,hMem
pop edi ;restore
.endif
pop esi ;restore
.endif
.endif
for older versions of internet explorer (and other browsers, i suspect), blank.html was a real physical file
newer versions, however, seem to have eliminated the file and use internal data
i am guessing it was for security reasons :P