MATLAB: Call dlls in for compiled application

dlls compiled application

Hi all

i built a app with app designer. I get an error "No class lib..\dev\bin\64-bit\nilibddc.dll." after install the app

One of the function i need to call the dll provided by NI http://www.ni.com/product-documentation/3727/en/#toc4.

Relative path is used in the function ".\dev\bin\64-bit\nilibddc.dll'"

I package the app and install in another PC. The GUI can not find the dll path and load the dlls.

Is something wrone here do define the dll path.

Or i do not coeectly take care of nilibddc_thunk_pcwin64.dll file?

Thanks a lot

libname = 'nilibddc';

NI_TDM_DLL_Path = '.\dev\bin\64-bit\nilibddc.dll';

NI_TDM_H_Path = '.\dev\include\64-bit\nilibddc_m.h';

if ~libisloaded(NI_TDM_DLL_Path)

% loadlibrary(NI_TDM_DLL_Path,NI_TDM_H_Path);

loadlibrary(NI_TDM_DLL_Path, @mylibraryfile);

libfunctions(NI_TDM_DLL_Path,'-full');

end

Best Answer

I have fixed the issue

1) created the prototype m–file & library_thunk_pcwin64.dll according https://www.mathworks.com/matlabcentral/answers/175546-how-to-call-loadlibrary-in-a-compiled-application-by-matlab-compiler-on-windows

2) Do not use relative path here for the function to call dlls. This is a mistake i made

filepath = fileparts(mfilename('fullpath'));

NI_TDM_DLL_Path = [filepath,'\dev\bin\64-bit\nilibddc.dll'];

3) package the app, update "Shared resources and helper files" to add the dll folder prototype m–file & library_thunk_pcwin64.dll into the app.

Related Solutions

MATLAB: How to call loadlibrary in a compiled application by MATLAB Compiler on Windows

There are two steps necessary in order to successfully deploy an application which uses the loadlibrary command.

1.) Create a prototype m-file

When deploying loadlibrary you have to create a prototype m-file and use that instead of a header file.

Let us assume you call loadlibrary like this

loadlibrary(library, header)

You would then need to call loadlibrary once like this in MATLAB in order to create a prototype m-file:

loadlibrary(library, header, 'mfilename', 'PrototypeName');

After the execution you will see that a PrototypeName.m file was created in the current folder. In the case you use a 64bit MATLAB you will also notice that a library_thunk_pcwin64.dll was created in addition. We will also need that file later one (64bit only).

After you created the prototype m–file you need to adjust the call to loadlibrary to be:

loadlibrary(library, @PrototypeName)

2.) Compile the application

When compiling the application you have to decide if you like to compile the library into the application or to ship it externally.

2.1) Compiling the library into the application

When you like to compile the DLL into the application you have to add the library as shared resource or helper file manually. You can do this with the -a option (if using the mcc command) or by dragging it under Other/Additional Files (as a helper file) if using one of the compiler apps. In addition when working with 64bit MATLAB you also have to include the library_thunk_pcwin64.dll manually.

2.2) Providing the library as external file

When you decide not to include the library into the application you can also copy the library in the same folder as the compiled application without the need to adjust your code. When working with 64bit, you have to compile the library_thunk_pcwin64.dll into the application. Otherwise the library_thunk_pcwin64.dll cannot be found at runtime resulting in a module not found error.

The benefit of this approach is that you can replace the library with a newer version without the need to recompile the whole MATLAB application. BUT replacing the library with a different version works only if the function signatures of the function in the library stay the same because the prototype m-file (and the library_thunk_pcwin64.dll on 64bit) is tied to the function signatures of the functions in the library.

MATLAB: Is there an example on how to use a libpointer of type stringPtrPtr with the function LOADLIBRARY in MATLAB 7.7 (R2008b)

The following example shows how to retrieve a string array (char ) from a Generic DLL function call. This example is based on National Instruments' TDM C DLL example (English and German available):

http://zone.ni.com/devzone/cda/epd/p/id/5957

% Load the DLL.
NI_TDM_DLL_Path = fullfile(pwd, '..\dev\bin\nilibddc.dll');
NI_TDM_H_Path = fullfile(pwd, '..\dev\include\nilibddc_m.h');
loadlibrary(NI_TDM_DLL_Path, NI_TDM_H_Path);
% Show functions and signatures.
% libfunctionsview('nilibddc')
% [...]

%Get the Channelgroup Property Names
%Get the number of Channelsgroup Property Names in this Channel Group
pnumchanpr = libpointer('uint32Ptr', 0);
% Get number of fields for the string array.
% In this case, MATLAB can directly write to the right-hand-side variable "pnumchanpr".
err = calllib('nilibddc', 'DDC_GetNumChannelGroupProperties', pgrps.Value(i), pnumchanpr);
% Create a cell array dimensioned as the expected output and use it to create a stringPtrPtr.
pnamchanpr = libpointer('stringPtrPtr', cell(1, pnumchanpr.value));
% Call function to retrieve the char** data.
% The C function is defined in the header file as follows:
% int __stdcall DDC_GetChannelGroupPropertyNames (DDCChannelGroupHandle channelGroup, 
%    char** propertyNames, unsigned int numPropertyNames);
%

% By executing "libfunctions('nilibddc', '-full')", you will see that MATLAB's
% interpretation of the function's signature is as follows:
% [int32, stringPtrPtr] DDC_GetChannelGroupPropertyNames(long, stringPtrPtr, uint32)
%
% In this case, MATLAB cannot retrieve the output value using the variable "pnamchanpr" that
% was passed on the right-hand-side of the function. That's why we need to specify a
% variable that will be used for the output on the left-hand-side. Always
% check the function's signature that is expected by MATLAB by calling the
% functions LIBFUNCTIONS or LIBFUNCTIONSVIEW.
[err outputStringArray] = calllib('nilibddc', 'DDC_GetChannelGroupPropertyNames', pgrps.Value(i), pnamchanpr, pnumchanpr.value);
% Display returned cell array.
outputStringArray
% outputStringArray = 
%     'name'
%     'description'
%     'Frequency'
% [...]
% Clean up.
%Close TDM or TDMS file
calllib('nilibddc','DDC_CloseFile',pfile.Value);
%Unload nilibddc.dll
unloadlibrary('nilibddc');

Best Answer

Related Solutions

MATLAB: How to call loadlibrary in a compiled application by MATLAB Compiler on Windows

MATLAB: Is there an example on how to use a libpointer of type stringPtrPtr with the function LOADLIBRARY in MATLAB 7.7 (R2008b)

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