Receiving strings in a Standard DLL
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From: Leo on 17 Jul 2010 11:51 I have some code I am thinking of sticking in a standard dll which needs to have strings passed to it. What is the best way to do this with me seeing the chance that non VB code could be calling this code. Should I use pointers and convert to a VB string? -- ClassicVB Users Regroup! comp.lang.basic.visual.misc Free usenet access at http://www.eternal-september.org
From: Mayayana on 17 Jul 2010 12:10 You can use strings OK, but you don't get the usual (hidden) conversion to and from ANSI/Unicode. If you want to send and retrieve strings as you would in VB, use StrConv(s, vbUnicode) on the incoming strings and StrConv(s, vbFromUnicode) when returning a string value. I've got a basic sample with info. here: www.jsware.net/jsware/vbcode.php5#vdll I developed it with a lot of help from an article here: http://windowsdevcenter.com/pub/a/windows/2005/04/26/create_dll.html |I have some code I am thinking of sticking in a standard dll which | needs to have strings passed to it. What is the best way to do this | with me seeing the chance that non VB code could be calling this code. | Should I use pointers and convert to a VB string? | | -- | ClassicVB Users Regroup! comp.lang.basic.visual.misc | Free usenet access at http://www.eternal-september.org | |
From: Kevin Provance on 17 Jul 2010 14:20 "Leo" <ttdhead(a)gmail.com> wrote in message news:i1sjhk$udb$1(a)news.eternal-september.org... :I have some code I am thinking of sticking in a standard dll which : needs to have strings passed to it. What is the best way to do this : with me seeing the chance that non VB code could be calling this code. : Should I use pointers and convert to a VB string? What language are you using to write the standard DLL? If it's your intention to use the DLL with VB, what's wrong with a COM DLL? I used them all the time without any problems, expecially where reusable code is concerned. If you plan to use VB to author the DLL with the various hacks available, there are caveats. If you're using the DLL with your VB project, then you don't need to worry about intiailizing the VB runtime (something you would have to do if the DLL was to be used with a language other than VB). As far as passing strings using this method, there are gotchas and hiccups along the way. The one time I experimented with it (but don't do it with production code) I took the route the SHLWAPI API uses and pass the strings as long pointers. Yes, there is an extra step involved, but it's faster and more reliable (which is up for debate, I suppose). Take a look here to see what I am talking about: http://msdn.microsoft.com/en-us/library/aa155716%28office.10%29.aspx. It talks about using string pointers instead of strings...plus reveals some cool APIs you may or may not have known about. :-) - Kev
From: Jim Mack on 17 Jul 2010 14:36 Leo wrote: > I have some code I am thinking of sticking in a standard dll which > needs to have strings passed to it. What is the best way to do this > with me seeing the chance that non VB code could be calling this > code. Should I use pointers and convert to a VB string? What language would you use to write this DLL? -- Jim Mack Twisted tees at http://www.cafepress.com/2050inc "We sew confusion"
From: Leo on 17 Jul 2010 22:13
Jim Mack wrote : > Leo wrote: >> I have some code I am thinking of sticking in a standard dll which >> needs to have strings passed to it. What is the best way to do this >> with me seeing the chance that non VB code could be calling this >> code. Should I use pointers and convert to a VB string? > > What language would you use to write this DLL? VB -- ClassicVB Users Regroup! comp.lang.basic.visual.misc Free usenet access at http://www.eternal-september.org |