Convert C# string to Byte for COM Interop -


i calling c++ com component using interop , marshalling requires 1 of parameters passed in ref byte. argument string. how convert string (or char array) byte pass method?

method idl

 [helpstring("method read")]     hresult _stdcall read(                     [in] unsigned char* path,                      [in] unsigned char command,                      [in] unsigned char nshortaddr,                      [out] short* pndatasize,                      [out] unsigned char** ppbydata,                      [out] unsigned long* pnerror);

the il

.method public hidebysig newslot virtual          instance void  read([in] uint8& path,                             [in] uint8 command,                             [in] uint8 nshortaddr,                             [out] int16& pndatasize,                             [out] native int ppbydata,                             [out] uint32& pnerror) runtime managed internalcall

the method in wrapper seen in visual studio

    public virtual void read(ref byte path, byte command, byte nshortaddr,   out short pndatasize, system.intptr ppbydata, out uint pnerror)

this poorly authored com interface. can work when used in-process c++ code. creator had intended. argument type declaration unsigned char* ambiguous, mean single byte passed reference indicate array of bytes. can use attributes in idl distinguish between 2 not used. type library importer therefore not assume else ref byte.

there's 1 decent fix if source idl can't updated, have edit interop library. decompiling existing 1 first ildasm.exe. edit argument type, best done creating dummy c# interface same declaration example. put humpty-dumpty ilasm.exe


Comments

Post a Comment

Popular posts from this blog

monitor web browser programmatically in Android? -

i've got tricky question here. need users make payment bank (namely barclaycard) in uk. so, have https url , add parameters (such amount pay, order reference, etc) url, start http connection intent.actionview, redirect user browser can enter credit card details on bank's webpage , make payment our account successfully. far ? the code use below (i changed values privacy reasons) problem is, need app when user has completed/failed/cancelled payment. barclaycardautomatically redirects particular url when payment has succeeded, 1 if failed. there no way of knowing when barclaycard payment has succeeded go android app somehow ? button cardbutton = (button) findviewbyid(r.id.card_button); cardbutton.setonclicklistener(new view.onclicklistener() { @override public void onclick(view arg0) { string prehashstring = new string(); string prohashstring = new string(); string shapassphrase = new string(); shapassphrase = "gsvth£h70zkh...
Read more

Shrink a YouTube video to responsive width -

i have youtube video embedded on our website , when shrink screen tablet or phone sizes stops shrinking @ around 560px in width. standard youtube videos or there can add code make go smaller? you can make youtube videos responsive css. wrap iframe in div class of "videowrapper" , apply following styles: .videowrapper { float: none; clear: both; width: 100%; position: relative; padding-bottom: 56.25%; padding-top: 25px; height: 0; } .videowrapper iframe { position: absolute; top: 0; left: 0; width: 100%; height: 100%; } the .videowrapper div should inside responsive element. padding on .videowrapper necessary keep video collapsing. may have tweak numbers depending upon layout.
Read more

wpf - PdfWriter.GetInstance throws System.NullReferenceException -

i'm trying create pdf document using itextsharp 5.3.4 using following document document = new document(); filestream stm = new filestream(filename, filemode.create); pdfwriter writer = pdfwriter.getinstance(document, stm); i'm getting system.nullreferenceexception following stack trace: system.nullreferenceexception occurred hresult=-2147467261 message=la référence d'objet n'est pas définie à une instance d'un objet. source=itextsharp stacktrace: à itextsharp.text.version.getinstance() innerexception: i've verified neither document nor stm null, , if select "continue" in vs12 document created - exception thrown. updated itextsharp 5.4.0 , it's still occurring. can't find information on anywhere - got ideas? make sure not catching exceptions. nullreferenceexception can 1 caught , handled inside itextsharp, don't care it. fact can continue supports theory. change following setting verify: debug -> exceptions ...
Read more