Evaluates an expression.
struct resbuf*
ade_expreval(
ads_name ename,
char* expr,
char* type);
Returns the value of the expression or NULL.
| ename | Optional drawing object name. Required if the expression uses object properties or data. |
| expr | Expression to evaluate. |
| type | Expected return type: "short", "long", "real", "string", or "point". |
The following sample displays the .Length property of a pline entity which has been converted to Meters.
A selection set of entities from the current drawing is created using acedSSGet(). Each entity is passed to ade_expreval()along with any additional parameters. The resbuf returned by ade_expreval() contains the converted result which is then displayed. Then it releases the resbuf, as required.
ads_name ename;
ads_name selectionSet;
char* pszExpr = "(* .LENGTH .3048)";
char* pszReturnType = "real";
struct resbuf* pEntLengthToM = NULL;
acedSSGet("x", NULL, NULL, NULL, selectionSet);
long ssLength;
acedSSLength( selectionSet, &ssLength; );
for( int i = 0; i < ssLength; ++i )
{
if( acedSSName(selectionSet, i, ename) == RTNORM )
{
pEntLengthToM = ade_expreval(ename, pszExpr, pszReturnType);
if (pEntLengthToM != NULL){
struct resbuf* rb = pEntLengthToM;
while(rb != NULL) {
acutPrintf(
"\nThe current entities .LENGTH value converted to Meters is: %.4lf"
, rb->resval.rreal);
rb = rb->rbnext;
}
}
}
}
acutRelRb(pEntLengthToM);