带有负载库Matlab的嵌套结构

从您的评论中可以看出，可以有不同的dll，但是导出的函数具有相同的原型，无论如何，我都会将库的管理委派给mex文件。

因此，请让我们考虑构建一个FmiManager.mex可以在matlab中使用的代码，如下所示：

[ok, msg] = FmiManager('SETUP', libraryName);
[hCallbacks] = FmiManager('CREATE_CALLBACKS', ... params for creating callbacks ...);
[hInstance] = FmiManager('CREATE_INSTANCE', hCallbacks, ... other params ...)
[...] = FmiManager('OTHER_COMMAND', ...);

这很简单，第一个参数是您要对库执行的操作，其他参数特定于要在c代码中调用的函数。

• SETUP 是一个额外的命令，用于动态更改与您链接的库。
• CREATE_CALLBACKS调用c函数创建回调并返回它们的句柄（例如，只需将c指针强制转换为“结构b”为int）
• CREATE_INSTANCE调用c函数以实例化主要组件并返回创建实例的句柄（例如，将“ struct a”再次简单地转换为int），并将回调的句柄作为输入（只需要在内部将其转换回“ struct b” C代码）
• OTHER_COMMAND 您可以根据需要将过程扩展到其他c功能...

这是一些伪代码，显示了如何构建此FmiManager.mex文件：

[FmiManager.c]

#include <mex.h>
#include <windows.h>
#include "FmiManager.h" // The header for this mex file
#include "fmi.h" // The header for types in your 'fmi' library

// Pointer to correct dll
static HINSTANCE hDll = NULL;

// Pointer to the function that creates the callbacks
typedef fmi2CallbackFunctions* (FMI_CALLCONV createCallBacksPtr *)(...)
static createCallBacksPtr createCallBacks = NULL;

// Pointer to the function that performs instantiation
typedef fmi2Component* (FMI_CALLCONV instanciatePtr *)(...)
static instanciatePtr instanciate = NULL;

// Mex entry point
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    // Arguments parsing
    if (nrhs < 1) { mexErrMsgTxt("Not enough input arguments."); return; }
    if (!mxIsChar(prhs[0])) { mexErrMsgTxt("First parameter must be a string."); return; }

    // Command selection
    if (commandIs(prhs[0], "SETUP")) { processSetup(nlhs, plhs, nrhs, prhs); }
    else if (commandIs(prhs[0], "CREATE_CALLBACKS")) { processCreateCallbacks(nlhs, plhs, nrhs, prhs); }
    else if (commandIs(prhs[0], "INSTANCIATE")) { processInstanciate(nlhs, plhs, nrhs, prhs); }
    else { mexErrMsgTxt("Unknown command or command not implemented yet."); }
}

// Processing 'SETUP' command
void processSetup(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    // Free previous library
    if (hDll != NULL) { FreeLibrary(hDll); hDll = NULL; }

    // Load the new one
    char* librayPath = getThisMexPath();
    ... load library from '*prhs' (i.e. hDll = loadLibrary(fullpath))...
    mxFree(librayPath);

    // Bind functions pointers
    createCallBacks = (createCallBacksPtr)GetProcAddress(hDll, "createCallbacks");
    if (createCallBacks == NULL) { mexErrMsgTxt("Failed to map 'createCallBacks'"); return; }

    instanciate = (instanciatePtr)GetProcAddress(hDll, "instanciate");
    if (instanciate == NULL) { mexErrMsgTxt("Failed to map 'instanciate'"); return; }
}

// Processing 'CREATE_CALLBACKS' command
void processCreateCallbacks(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    ... unpack '*prhs' ...

    int hCallbacks = (int)createCallback(...); // Function has been binded during setup

    ... pack 'hCallbacks' into '*plhs' ...
}

// Processing 'INSTANCIATE' command
void processInstanciate(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    ... unpack '*prhs' ...

    int hInstance = (int)instanciate(...); // Function has been binded during setup

    ... pack 'hInstance' into '*plhs' ...
}

// Check if some command is really some givent one
bool commandIs(const mxArray* mxCommand, const char* command)
{
    double result;
    mxArray* plhs1[1];
    mxArray* prhs1[1];
    mxArray* plhs2[1];  
    mxArray* prhs2[2];

    if (mxCommand == NULL) { mexErrMsgTxt("'mxCommand' is null"); return false; }
    if (command == NULL) { mexErrMsgTxt("'command' is null"); return false; }
    if (!mxIsChar(mxCommand)) { mexErrMsgTxt("'mxCommand' is not a string"); return false; }

    // First trim
    prhs1[0] = (mxArray*)mxCommand;
    mexCallMATLAB(1, plhs1, 1, prhs1, "strtrim");

    // Then compare
    prhs2[0] = mxCreateString(command);
    prhs2[1] = plhs1[0];
    mexCallMATLAB(1, plhs2, 2, prhs2, "strcmpi");

    // Return comparison result
    result = mxGetScalar(plhs2[0]);  
    return (result != 0.0);
}

// Obtain the path of current mex file
// CAREFUL: Use mxFree on return pointer !!
char* getThisMexPath()
{
    mxArray *rhs[1], *lhs[1];
    char *path, *name;

    size_t lenpath, lenname, n;
    rhs[0] = mxCreateString("fullpath");
    mexCallMATLAB(1, lhs, 1, rhs, "mfilename");
    mxDestroyArray(rhs[0]);
    path = mxArrayToString(lhs[0]);
    mxDestroyArray(lhs[0]);

    mexCallMATLAB(1, lhs, 0, rhs, "mfilename");
    name = mxArrayToString(lhs[0]);
    mxDestroyArray(lhs[0]);

    lenpath = strlen(path);
    lenname = strlen(name);
    n = lenpath - lenname;
    path[n] = '\0';

    mxFree(name);

    return path; // Don't forget mxFree !!! 
}

我希望您会喜欢这种替代解决方案。它的主要优点是您不必费心确保在matlab中创建的结构将适合c端代码。一切都委托给.mex文件（即，在c中），并作为句柄传递给matlab。