idtcpserver问题(如何知道writebuffer已空)

各位看一下为什么这样还是会出现超出缓冲区
假设 readcount:=$60000;readfile(hdevice,readstr[0],readcount);
i:=0;
while ReadCount>$8192 do
  begin
    athread.connection.writebuffer(readstr[i*$8192],$8192,true);
    dec(readcount,$8192);
    inc(i);
    sleep(1000);
  end;
if readcount>0 then athread.connection.writebuffer(readstr[i*$8192],readcount,true);只要readcount初始大于32K就出错,我怎么才能知道wirtebuffer中的数据被客户端读走了呢