学步园

resbuf(Result buffer structure:结果缓存区表)是用来处理所有AutoCAD的基本数据类型的.
struct resbuf {                                                 
        struct resbuf *rbnext;  //指向下一个resbuf的指针
        short restype;  //查询参数的种类,是一个DXF组码 
        union ads_u_val resval; //相应种类的匹配值
};
从定义上我们可以看出,结构resbuf是一个链表,每一个缓冲区指定一个检查参数和匹配的值;缓冲区的restype段是一个DXF组码,它指示要查询

的参数的种类,而缓冲区的resval域指定要匹配的值.
union ads_u_val {
   ads_real rreal;
   ads_real rpoint[3];
   short rint;
   char *rstring;
   long rlname[2];
   long rlong;  
   struct ads_binary rbinary;
   unsigned char ihandle[8];  //可能临时使用,目前仅仅为内部使用
};

//打印扩展数据列表,<br /> void<br /> printList(struct resbuf* pRb)<br /> {<br /> int rt, i;<br /> char buf[133];</p> <p> for (i = 0;pRb != NULL;i++, pRb = pRb->rbnext) {<br /> if (pRb->restype < 1010) {<br /> rt = RTSTR;<br /> } else if (pRb->restype < 1040) {<br /> rt = RT3DPOINT;<br /> } else if (pRb->restype < 1060) {<br /> rt = RTREAL;<br /> } else if (pRb->restype < 1071) {<br /> rt = RTSHORT;<br /> } else if (pRb->restype == 1071) {<br /> rt = RTLONG;<br /> } else {<br /> /*记住,这里else可能为>1071的数,从而为后面的pRb->restype == RTSHORT做了工作,<br /> #define RTNONE 5000<br /> #define RTREAL 5001<br /> #define RTPOINT 5002<br /> #define RTSHORT 5003<br /> #define RTANG 5004<br /> #define RTSTR 5005<br /> #define RTENAME 5006<br /> #define RTPICKS 5007<br /> #define RTORINT 5008<br /> #define RT3DPOINT 5009<br /> #define RTLONG 5010<br /> #define RTVOID 5014<br /> */<br /> rt = pRb->restype;<br /> }</p> <p> switch (rt) {<br /> case RTSHORT:<br /> if (pRb->restype == RTSHORT) {<br /> acutPrintf(<br /> "RTSHORT : %d/n", pRb->resval.rint);<br /> } else {<br /> acutPrintf("(%d . %d)/n", pRb->restype,<br /> pRb->resval.rint);<br /> };<br /> break;</p> <p> case RTREAL:<br /> if (pRb->restype == RTREAL) {<br /> acutPrintf("RTREAL : %0.3f/n",<br /> pRb->resval.rreal);<br /> } else {<br /> acutPrintf("(%d . %0.3f)/n", pRb->restype,<br /> pRb->resval.rreal);<br /> };<br /> break;</p> <p> case RTSTR:<br /> if (pRb->restype == RTSTR) {<br /> acutPrintf("RTSTR : %s/n",<br /> pRb->resval.rstring);<br /> } else {<br /> acutPrintf("(%d . /"%s/")/n", pRb->restype,<br /> pRb->resval.rstring);<br /> };<br /> break;</p> <p> case RT3DPOINT:<br /> if (pRb->restype == RT3DPOINT) {<br /> acutPrintf(<br /> "RT3DPOINT : %0.3f, %0.3f, %0.3f/n",<br /> pRb->resval.rpoint[X],<br /> pRb->resval.rpoint[Y],<br /> pRb->resval.rpoint[Z]);<br /> } else {<br /> acutPrintf("(%d %0.3f %0.3f %0.3f)/n",<br /> pRb->restype,<br /> pRb->resval.rpoint[X],<br /> pRb->resval.rpoint[Y],<br /> pRb->resval.rpoint[Z]);<br /> }<br /> break;</p> <p> case RTLONG:<br /> acutPrintf("RTLONG : %dl/n", pRb->resval.rlong);<br /> break;<br /> }</p> <p> //这里为什么要有这个,主要是为了当记录多的时候,起到翻页功能,就要cmd dir /p类似<br /> if ((i == 23) && (pRb->rbnext != NULL)) {<br /> i = 0;<br /> acedGetString(0,<br /> "Press <ENTER> to continue...", buf);<br /> }<br /> }<br />