最好不要用switch来枚举，改用循环语句

short int iBoxCount,i;//iBoxCount为Check Box选项数目，与曲线数目一致

long int iBit;

iBoxCount=GetPropWord("main1.Pdl","Check Box1","BoxCount");

iBit=1;

for (i=1;i<=iBoxCount;i++)

{

   SetPropWord("main1.Pdl","Trend","TrendIndex",i-1);

   if ((value & iBit)>0)

      SetPropBOOL("main1.Pdl","Trend","TrendVisible",1); //显示

   else

      SetPropBOOL("main1.Pdl","Trend","TrendVisible",0); //隐藏

   iBit=iBit*2;

}