Passing Basic Array of User-Defined Type to C (27302)

SUMMARY

The following example demonstrates how to pass an array of user-defined-type records from compiled Basic to Microsoft C.

This information about inter-language calling applies to QuickBasic Versions 4.00, 4.00b, and 4.50 for MS-DOS and to Microsoft Basic Compiler Versions 6.00 and 6.00b for MS-DOS and MS OS/2.

MORE INFORMATION

For more information about passing other types of parameters between Basic and C, and a list of which Basic and C versions are compatible with each other, query in the Microsoft Knowledge Base using the following word:

BAS2C

Code Example

REM ===== Basic PROGRAM =====

TYPE record
   a AS INTEGER
   b AS STRING * 20
   c AS SINGLE
END TYPE
DECLARE SUB TypeArray CDECL (_
            BYVAL p1o AS INTEGER,_
            BYVAL p1s AS INTEGER)
CLS
DIM element(10) AS record
FOR I = 0 TO 10
    element(I).a = 128 + I
    element(I).b = STR$(I) + ". " + DATE$ + CHR$(0)
    element(I).c = 39.6 * I
NEXT I
CALL TypeArray(VARPTR(element(0)), VARSEG(element(0)))
END

/* ===== C ROUTINE ===== */ 

#include <stdio.h>
struct record{
       int a;
       char b[20];
       float c;
};
void TypeArray(element)
     struct record far *element;
 {
    int i;
    for (i=0;i<3;i++)
      {
        printf("Record[%d].A = %d\n",i,element->a);
        printf("Record[%d].B = %s\n",i,element->b);
        printf("Record[%d].C = %f\n",i,element->c);
        printf("\n");
        element++;
      };
 }

===== OUTPUT =====

Record[0].A = 128
Record[0].B =  0. 02-02-1988
Record[0].C = 0.000000

Record[1].A = 129
Record[1].B =  1. 02-02-1988
Record[1].C = 39.599998

Record[2].A = 130
Record[2].B =  2. 02-02-1988
Record[2].C = 79.199997