帮忙,请教一个问题!

Question

inc(foundstr,length(foundstr));foundstr在执行这条语句之前为"want to" 在执行之后就是"",这是为什么?inc()对它进行了什么操作?inc()不是对参数进行加值的操作吗!

Answer 1

foundstr must be a variable of an ordinal type 
不能是string

Answer 2

同志们那是一条正确的语句.完成的程序如下:  retval:=findfirst(dlbdirectories.directory + '\*.txt',faAnyFile,searchrec);
  try
     while retval=0 do
        begin
           fname:=searchrec.Name;
          memmapfile:=tmemmapfile.create(fname,fmopenread,0,true);
           try
              findstring:=edtsearchstring.text;
              wordcount:=0;
              foundstr:=strpos(pchar(memmapfile.data),pchar(findstring));
              if foundstr<>nil then
              begin
                  repeat
                    inc(wordcount);
                    showmessage('start foundstr:' + foundstr);
                    inc(foundstr,length(foundstr));
                    showmessage('end foundstr:' + foundstr);
                    foundstr:=strpos(pchar(foundstr),pchar(findstring));
                  until foundstr=nil;
                  lbfilesfound.items.add(searchrec.name+' . '+inttostrwordcount));
              end;
              retval:=findnext(searchrec);