请问lwip的http输出函数的问题该如何解决？

最近在调试http的应用，打算让网页输出一个表格，表格应该有250行
但实际上输出只有22行，
static char http_buf[512]={0};
/*-----------------------------------------------------------------------------------*/
static err_t
http_recv(void *arg, struct tcp_PCB *pcb, struct pbuf *p, err_t err)//处理输入数据
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struct http_state *hs;
data = p->payload;//把接收到的数据指针交给data
  for(i=0;i<250;i++)
  {
      
//AlARM_Record_Read(&Alarm_record,i);//刷新数据
Alarm_Record_Read(&Alarm_record,(i)%ALARM_RECORD_PAGE_AMOUNT);//刷新数据
//i=i%ALARM_RECORD_PAGE_AMOUNT;
      ret=sprintf(http_buf, "");
ret+=sprintf(http_buf+ret, "%04d%03d%03d",Alarm_record.AlarmEvent.Zone,Alarm_record.AlarmEvent.EventCode,Alarm_record.AlarmEvent.EventType);
ret+=sprintf(http_buf+ret,"%04d-%2d-%2d ",Alarm_record.AlarmEvent.Time.tm_year,Alarm_record.AlarmEvent.Time.tm_mon,Alarm_record.AlarmEvent.Time.tm_mday);
ret+=sprintf(http_buf+ret,"%2d:%02d:%02d",Alarm_record.AlarmEvent.Time.tm_hour,Alarm_record.AlarmEvent.Time.tm_min,Alarm_record.AlarmEvent.Time.tm_sec);
ret+=sprintf(http_buf+ret,"%d%d",Alarm_record.AlarmFlag[2],Alarm_record.AlarmFlag[3]);
ret+=sprintf(http_buf+ret, "");
  

//i=i%ALARM_RECORD_PAGE_AMOUNT;
//for(j=0;j++;j {
       hs->file =(char*)&http_buf;//
hs->left = ret;
   send_data(pcb, hs);
tcp_output(pcb);
    tcp_sent(pcb, http_sent);
tcp_output(pcb);
}
//tcp_write(pcb,http_buf,sizeof(http_buf),0);
    memset(http_buf,0,sizeof(http_buf));//清空数据  
}
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