[ANSWERED] How to use CLSIDFromString()

[TI-994A]

Hello everyone. There are some very good examples in the use of CoCreateInstance() in this forum, but I can't find any of CLSIDFromString(). Is this function usable from PureBasic? I've been trying out this routine which I found in this forum, but to no success:

Code: Select all

Define CLSID_ShellLink.CLSID, shlCLSID.s, hRes.l
shlCLSID = "{00021401-0000-0000-C000-000000000046}"
hRes =  CLSIDFromString_(@shlCLSID , @CLSID_ShellLink)
Select hRes
 Case #NOERROR
    Debug "Success"
 Case #CO_E_CLASSSTRING
    Debug "The class string was improperly formatted."
 Case #REGDB_E_CLASSNOTREG
    Debug "The CLSID corresponding to the class string was not found in the registry."
 Case #REGDB_E_READREGDB
    Debug "The registry could not be opened for reading."
 Default
    Debug hRes
EndSelect

Am I doing it wrongly?

---> Please see netmaestro's solutions below. Thank you netmaestro!

[Josh]

Do you have activated Unicode?

[netmaestro]

This api doesn't take an asciiz, it takes an olestring (or bstr). If you don't wish to compile as Unicode, Give these a try:

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; ASCII only for this version...

Procedure.l ansi2bstr(ansi.s)
  Size.l=MultiByteToWideChar_(#CP_ACP,0,ansi,-1,0,0)
  Dim unicode.w(Size)
  MultiByteToWideChar_(#CP_ACP, 0, ansi, Len(ansi), unicode(), Size)
  ProcedureReturn SysAllocString_(@unicode())
EndProcedure

Define CLSID_ShellLink.CLSID, shlCLSID.s, hRes.l
shlCLSID = "{00021401-0000-0000-C000-000000000046}"
hRes =  CLSIDFromString_(ansi2bstr(shlCLSID) , @CLSID_ShellLink)
Select hRes
 Case #NOERROR
    Debug "Success"
 Case #CO_E_CLASSSTRING
    Debug "The class string was improperly formatted."
 Case #REGDB_E_CLASSNOTREG
    Debug "The CLSID corresponding to the class string was not found in the registry."
 Case #REGDB_E_READREGDB
    Debug "The registry could not be opened for reading."
 Default
    Debug hRes
EndSelect

Another approach, using a Purebasic pseudotype, should also work in either mode:

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;ASCII or Unicode are both OK for this version

Prototype CLSIDFromString(str.p-bstr, *pClsID.CLSID)

Procedure CLSIDFromString(*string, *pClsID.CLSID)
  hres = CLSIDFromString_(*string, *pClsID)
  If hRes = #NOERROR
    ProcedureReturn 1
  Else
    ProcedureReturn 0
  EndIf
EndProcedure

Global myCLSIDFromString.CLSIDFromString = @CLSIDFromString()

Define CLSID_ShellLink.CLSID, shlCLSID.s, hRes.l

shlCLSID = "{00021401-0000-0000-C000-000000000046}"

Debug Hex(CLSID_ShellLink\data1, #PB_Long) ; nothing done to it yet, should be 0
hRes =  myCLSIDFromString(shlCLSID, @CLSID_ShellLink)
Debug Hex(CLSID_ShellLink\data1, #PB_Long) ; should now be 21401

[TI-994A]

Do you have activated Unicode?

Hi Josh. You got it right; thank you.

This api doesn't take an asciiz, it takes an olestring (or bstr).

Hi netmaestro! Works perfectly for my requirements with CoCreateInstance(). Thanks for the tips about UNICode, ASCII, OLEString, bStr, etc. I read them up, but honestly would never have figured them out on my own. Thank you for the examples and for all your help.

[Josh]

@TI-994A

If you use b-strings, don't forget to free them. Otherwise you get a lot of memory leaks. I don't think, they are automatic freed after ending you program.

[TI-994A]

@TI-994A
If you use b-strings, don't forget to free them. Otherwise you get a lot of memory leaks. I don't think, they are automatic freed after ending you program.

Hello again Josh. Thanks for the heads-up. However, I can't seem to find the function for freeing-up such pseudotypes. From the forum examples that I've seen, we need to use SysFreeString() for bStr pointers created with SysAllocString(). But these functions expect numeric pointers, and not strings.

How should I free shlCLSID.s in netmaestro's example?

[netmaestro]

You don't need to free anything using Purebasic pseudotypes.

[TI-994A]

You don't need to free anything using Purebasic pseudotypes.

That's great. Thanks again guys; really appreciate all your valuable input, and especially the solution.

[Josh]

if you use netmaestros first example, you have to change the code a little bit. Change also the procedure return type from .l to .i, its a pointer.

Code: Select all

; ASCII only for this version...

Procedure.i ansi2bstr(ansi.s)
  Size.l=MultiByteToWideChar_(#CP_ACP,0,ansi,-1,0,0)
  Dim unicode.w(Size)
  MultiByteToWideChar_(#CP_ACP, 0, ansi, Len(ansi), unicode(), Size)
  ProcedureReturn SysAllocString_(@unicode())
EndProcedure

Define CLSID_ShellLink.CLSID, shlCLSID.s, hRes.l, *bStr
shlCLSID = "{00021401-0000-0000-C000-000000000046}"
*bStr = ansi2bstr(shlCLSID)
hRes =  CLSIDFromString_(*bStr , @CLSID_ShellLink)
Select hRes
 Case #NOERROR
    Debug "Success"
 Case #CO_E_CLASSSTRING
    Debug "The class string was improperly formatted."
 Case #REGDB_E_CLASSNOTREG
    Debug "The CLSID corresponding to the class string was not found in the registry."
 Case #REGDB_E_READREGDB
    Debug "The registry could not be opened for reading."
 Default
    Debug hRes
EndSelect
SysFreeString_(*bStr)

If I often call such procedures like ansi2bstr, i use the following code:

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; ASCII only for this version...

Procedure.i ansi2bstr(ansi.s)
  Static bStr.i
  
  SysFreeString_(bStr)
  If ansi = ""
    ProcedureReturn
  EndIf

  Size.l=MultiByteToWideChar_(#CP_ACP,0,ansi,-1,0,0)
  Dim unicode.w(Size)
  MultiByteToWideChar_(#CP_ACP, 0, ansi, Len(ansi), unicode(), Size)
  bStr = SysAllocString_(@unicode())
  ProcedureReturn bStr

EndProcedure

Define CLSID_ShellLink.CLSID, shlCLSID.s, hRes.l
shlCLSID = "{00021401-0000-0000-C000-000000000046}"
hRes =  CLSIDFromString_(ansi2bstr(shlCLSID) , @CLSID_ShellLink)
Select hRes
 Case #NOERROR
    Debug "Success"
 Case #CO_E_CLASSSTRING
    Debug "The class string was improperly formatted."
 Case #REGDB_E_CLASSNOTREG
    Debug "The CLSID corresponding to the class string was not found in the registry."
 Case #REGDB_E_READREGDB
    Debug "The registry could not be opened for reading."
 Default
    Debug hRes
EndSelect

With this code it's secured, that all the running time is only one bString stored by this procedure. At the end of you program you call one time:

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ansi2bstr("")

[TI-994A]

With this code it's secured, that all the running time is only one bString stored by this procedure. At the end of you program you call one time:

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ansi2bstr("")

Hi Josh. That's a nice and neat way to release resources that can be implemented in other procedures as well. Thanks for the pointer.