[MSCE 10.16 C#] How to get actual config variable value instead of expanded value

Hi Mike Robertson,

As explained here GetVariable takes a simplified path forward in MicroStation CONNECT to help eliminate: improper use, dormant memory allocations and confusion when calling: mdlSystem_getCfgVar() vs the more often needed call to: mdlSystem_expandCfgVar(). If there is a need to obtain the unexpanded variable value then it is recommended to import and call msMacro_expandMacroExpression() located in mdlbltin.lib passing false as the last parameter value.

When providing a forward declaration using the SDK types, it should appear as:

MSCORE_EXPORT StatusInt     msMacro_expandMacroExpression(WStringR expansion, WCharCP expression, bool immediate, bool fmtExpansion)

When providing a forward declaration using Microsoft types, it should appear as:

int __cdecl msMacro_expandMacroExpression(struct Bentley::WString & __ptr64,wchar_t const * __ptr64,bool,bool)

HTH,
Bob 

Robert,

Any chance you could point me in the right direction, do I import a lib file using the DllImport attribute like I would for accessing the ustation.dll file?

I can't find documentation on msMacro_expandMacroExpression method in the MicroStation API Documentation (doing a search on just msMacro shows no hits in the documentation)

Hi Mike

Mike Robertson said:

I can't find documentation on msMacro_expandMacroExpression method in the MicroStation API Documentation

I think it's not documented anywhere. But as Bob wrote, it is available in mdlbltin.lib and published also in ustation.dll

Mike Robertson said:

do I import a lib file using the DllImport attribute like I would for accessing the ustation.dll file?

I think you should use ustation.dll in DllImport.

Mike Robertson said:

Any chance you could point me in the right direction

Because P/Invoke is standard NET Framework feature from version 1, it's is well documented (including how data types are marshalled), and for more complicated marshalling a lot of tutorials and discussions can be found on Internet.

With regards,

  Jan

Using Dependency Walker I can see the declaration:

int __cdecl msMacro_expandMacroExpression(struct Bentley::WString & __ptr64,wchar_t const * __ptr64,bool,bool)

In my code I have the following:

[DllImport("ustation.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Cdecl)]
static extern int msMacro_expandMacroExpression(ref string expansion, string expression, bool immediate, bool fmtExpansion);

Then inside a method I call:

string output = string.Empty;
string expression = "MS_REPORT_OUT";
int statusInt = msMacro_expandMacroExpression(ref output, expression, true, false);

The code throws the following exception:

"Unable to find an entry point named 'msMacro_expandMacroExpression' in DLL 'ustation.dll'

I tried using both Int32 & Int64 for the return type, are my parameter types wrong?

Using Dependency Walker I can see the declaration:

int __cdecl msMacro_expandMacroExpression(struct Bentley::WString & __ptr64,wchar_t const * __ptr64,bool,bool)

In my code I have the following:

[DllImport("ustation.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.Cdecl)]
static extern int msMacro_expandMacroExpression(ref string expansion, string expression, bool immediate, bool fmtExpansion);

Then inside a method I call:

string output = string.Empty;
string expression = "MS_REPORT_OUT";
int statusInt = msMacro_expandMacroExpression(ref output, expression, true, false);

The code throws the following exception:

"Unable to find an entry point named 'msMacro_expandMacroExpression' in DLL 'ustation.dll'

I tried using both Int32 & Int64 for the return type, are my parameter types wrong?

Mike Robertson said:

Unable to find an entry point named 'msMacro_expandMacroExpression' in DLL 'ustation.dll'

Then that function must be implemented in another DLL.  Use Windows tools to search the installed DLLs to find which one exports the function you want.  For example, DLL Export Viewer.

Jon,

Using Dll Export Viewer the method is located in the ustation.dll. I'm wondering if my declaration of parameter types is incorrect so the method signature is not found.

Mike Robertson said:

I'm wondering if my declaration of parameter types is incorrect so the method signature is not found

Probably.  Here's Bob's function definition...

StatusInt     msMacro_expandMacroExpression(WStringR expansion, WCharCP expression, bool immediate, bool fmtExpansion)

The first arg is a C++ reference.  I don't know how to translate that to C# — consult Microsoft web sites. ref string expansion must be wrong, because a Bentley WString is not a C# string.

The second arg is a pointer-to-string, and I think you can use a C# string as you have.

Third and fourth args are pass-by-value bools.

Hi Mike Robertson,

FYI. I updated my original response above and provided forward declarations - originally the first containing MicroStation Data Types needed and (now) second - added the pure underlying Microsoft Data Types expected too.

Please try the Microsoft Data Type declaration and see if it helps you access msMacro_expandMacroExpression.

HTH,
Bob