Call questdlg from C S-Function

Hello, Is it possible to call questdlg(...) from within a simple C S-Function AND get the resulting answer? Please provide an example. Thank You

[Allen Peacock]

Hello and thanks for the quick response. I have followed your reference and this is what I produced:

#include "mex.h"
void 
mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray  *prhs[])
{
    mxArray *lhs[1];
    char sArray[15] = "Are you sure?";
    (void) prhs;           /* unused parameter */
  
    /* Check for proper number of input and output arguments */    
    if (nrhs != 0) {
  mexErrMsgTxt("No input arguments required.");
    } 
    if(nlhs > 1){
  mexErrMsgTxt("Too many output arguments.");
    } 
  /* Display a question dialog & get response */
  mexCallMATLAB(1, lhs, 1, sArray, "questdlg");  
}

It mex's without error. Unfortunately I get a Stack Dump/Trace when calling it. Not sure why it fails. Can you help?

Answer 1

[A Jenkins]

You can use mxCreateString to hold your string value.

#include "mex.h"
void 
mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray  *prhs[])
{
    mxArray    *lhs[1];
    mxArray    *pArray;
    const char sArray[] = "Are you sure?";

      /* Check for proper number of input and output arguments */
      if (nrhs != 0) {
          mexErrMsgTxt("No input arguments required.");
      }
      if(nlhs > 1){
          mexErrMsgTxt("Too many output arguments.");
      }

      /* Create a string array. */
      pArray = mxCreateString(sArray);

      /* Display a question dialog & get response */
      mexCallMATLAB(1, lhs, 1, &pArray, "questdlg");

      /* Write the output back to MATLAB */
      plhs[0] = lhs[0];

      /* When finished with the string array, free its memory. */
      mxDestroyArray(pArray);

}

[Allen Peacock]

Perfect! It worked like a charm. Thanks A Jenkins.

Answer 2

[Kaustubha Govind]

Yes, you can use mexCallMATLAB to call MATLAB functions from a C-MEX S-function. Please refer to the examples in the documentation.

[Allen Peacock]

Sorry, I may have put my response/question in the wrong spot. Here it is again: Hello and thanks for the quick response. I have followed your reference and this is what I produced:

#include "mex.h"
void 
mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray  *prhs[])
{
    mxArray *lhs[1];
    char sArray[15] = "Are you sure?";
    (void) prhs;           /* unused parameter */
  
    /* Check for proper number of input and output arguments */    
    if (nrhs != 0) {
  mexErrMsgTxt("No input arguments required.");
    } 
    if(nlhs > 1){
  mexErrMsgTxt("Too many output arguments.");
    } 
  /* Display a question dialog & get response */
  mexCallMATLAB(1, lhs, 1, sArray, "questdlg");  
}
It mex's without error. Unfortunately I get a Stack Dump/Trace when calling it. Not sure why it fails. Can you help?