[ARX函数]：openDWG异常：“Unhandled exception in dwg.exe:0XC0000005:Access Viola

ddpo1982

我在调试读取DWG文件时候，下面函数中出现异常
void writebindatablob(AD_VMADDR blob)
{
  PAD_BLOB_CTRL bcptr;
  long bytesleft;
  short bytestoread;
  short i;
  char asciibuf[260],binbuf[128],*cptr,*bptr;

  bcptr=adStartBlobRead(blob);
  
bytesleft=adBlobSize(bcptr);//出现异常(Unhandled exception in dwg.exe:0XC0000005:Access Violation)
  while (bytesleft)
  {
    if (bytesleft<127)
                bytestoread=(short)bytesleft;
    else
                bytestoread=127;
    adReadBlobBytes(bcptr,binbuf,bytestoread);
    cptr=asciibuf;
    bptr=binbuf;
    for (i=0; i<bytestoread; i++)
        {
      sprintf(cptr,"%.02X",(*bptr & 255));
      bptr++;
      cptr+=2;
    }
    *cptr=0;

/*
    exampleprintf("bin data:\n");
    exampleprintf("%s\n",asciibuf);
*/
    bytesleft-=bytestoread;
  }
  adEndBlobRead(bcptr);
}


求高手指点，谢谢！