[求助]用鼠标选择对象的问题

sencewm

依然是菜鸟求助
我用UIStyler建立了一个按钮，那如何实现：点击该按钮后可以用鼠标选择一曲线，然后获得它的中点，我的程序如下，但是似乎总是死循环。
int GP_action_0_act_cb ( int dialog_id,
4 M9 ^* V/ C. x8 N5 K% i7 G1 y             void * client_data,
$ r1 _" ?3 A% p' `4 s/ v% M             UF_STYLER_item_value_type_p_t callback_data)
{
     /* Make sure User Function is available. */  
2 t$ d' A9 v5 Y! _% V     if ( UF_initialize() != 0)
          return ( UF_UI_CB_CONTINUE_DIALOG );
, d# T+ h8 u8 N4 u
     /* ---- Enter your callback code here ----- */
7 J, C5 h) i1 M9 T) p" q. i8 Dchar message[133];
message[0]='\0';
strcpy(message, "请选择一条曲线");
1 O8 C3 ?$ i4 K. x4 vUF_UI_selection_options_t opts;
UF_UI_mask_t mask;
4 |  e/ N4 T, G% F( Uint response;
tag_t object, view;
double cursor[3];
, X! c. _4 T9 ^* U2 i9 Cint unhighlight=0;
! {% M) a7 E. q# A

0 q8 i, p% G6 f2 V' n& E
UF_initialize();
opts.other_options=0;
8 W& h, X8 a. H3 T) a- t  @opts.reserved=NULL;
& a9 n2 Q- [+ X9 K5 Copts.num_mask_triples=1;
* @2 Q+ F, o, b; [: V# L  Qopts.mask_triples=&mask;
* h7 }" E& p% U0 }8 Q8 B2 h  y1 C, @
6 k* N/ r+ q5 B0 i- E& Q* Lopts.mask_triples->object_type=UF_spline_type;
2 z) R: b) O* H6 ?. ]$ m) fopts.mask_triples->object_subtype=0;
opts.mask_triples->solid_type=0;

7 O6 d- n1 A, v2 s! f1 H0 _4 b, Fopts.scope=UF_UI_SEL_SCOPE_ANY_IN_ASSEMBLY;
( b, D# L- C3 f, gdouble port[3];


5 }2 X: [  E1 s2 J3 u+ s$ f% ?. t8 b! Xdo{int irc=UF_UI_select_single(message, &opts, &response, &object, cursor, &view);}

while (!(response==UF_UI_OBJECT_SELECTED));
if (response!=UF_UI_OBJECT_SELECTED)
{
3 U( Q# x$ y: w0 p; N/ Yuc1601("No Curve Selected",1);
UF_terminate ();
return (UF_UI_CB_CONTINUE_DIALOG);
}       
% D& V8 D+ P: P9 X9 O  
7 B6 ^) h* Y6 D8 K
0 r7 T' v; \8 }9 X) [7 rint ret=UF_MODL_ask_curve_props(object,0.5,port,NULL,NULL,NULL,NULL,NULL);
7 [: O: D* {: D0 i  G3 _  char message2[133];
' f& s7 b9 p! n& C- b, r  message2[0]='\0';
0 _9 _8 Y* V) x0 [9 {  sprintf (message2, "曲线中点坐标为：%f,%f,%f",port[0],port[1],port[2]);
  uc1601(message2,1);

. Z& n" S' }' b- I9 R, }: U- p4 e

UF_terminate ();
8 A+ F. l' Q! A1 Hreturn (UF_UI_CB_CONTINUE_DIALOG);
   }