[ARX函数]：向Autolisp返回变量值的问题

h2023197

在ARX中有如下的句子：  
int ff=10;
acedRetInt(ff);
执行以后，在AutoCAD命令行下输入  !ff   ,返回nil,没有值是怎么回事啊？

ishou

int

acedPutSym(

const char * sname,

struct resbuf * value);

sname The symbol name
value A pointer to a result-buffer list that contains the value to set the symbol; must contain values of types that can be represented in AutoLISP

Sets the value of an AutoLISP symbol.

Warning This command can be used in the ARX program environment only when AutoCAD sends the message kInvkSubrMsg to the application.

To set the value of the AutoLISP symbol to nil, make the following assignment:

value->restype = RTNIL;

If sname is not the name of a current symbol, acedPutSym() creates a new AutoLISP symbol with this name and assigns it the value.

Note An acedPutSym() function call can create a new AutoLISP symbol that AutoLISP cannot access--for example, by including illegal characters in the symbol name, such as "pair(s". An acedGetSym() call can access such symbols, but they will cause an error in a future upgrade or release of AutoCAD. Your programs should not rely on this capability.

The acedPutSym() function returns RTNORM if it succeeds; otherwise, it returns RTERROR. When acedPutSym() fails, it sets the system variable ERRNO to a value that indicates the reason for the failure.