请问这段程序是啥意思，谢谢

[jingtuzhong]

procedure Ttcpthread.addonline;
var
userdata: Ruserdata;
begin
IdTCPClient.ReadBuffer(userdata, sizeof(userdata));
EnterCriticalSection(CS);
setlength(online, high(online) + 2);
online[high(online)] := userdata;
//更新显示
with onlineview.Items.Add do
begin
Caption := userdata.username;
imageindex := userdata.whatdoing;
subitems.Add(userdata.email);
end;
LeaveCriticalsection(CS);
end

[不担心]

procedure Ttcpthread.addonline;
var
userdata: Ruserdata; //定义数据类型
begin
IdTCPClient.ReadBuffer(userdata, sizeof(userdata)); 读取userdate数据岛indy控件中
EnterCriticalSection(CS); //进入保护临界状态,就是其他线程不能访问
setlength(online, high(online) + 2); 设置online数组数据个数加2，就是可以多存放两个
online[high(online)] := userdata; 把userdate赋值给online数据最大下标的那个
//更新显示
with onlineview.Items.Add do //在listview中显示数据
begin
Caption := userdata.username; //第一列显示userdata结构体重的username字段
imageindex := userdata.whatdoing; //设置图标索引值为结构体中的whatdoing子都
subitems.Add(userdata.email); //添加第二列为结构体中email字段
end;
LeaveCriticalsection(CS); //离开保护状态
end

[okgxs]

IdTCPClient.ReadBuffer(userdata, sizeof(userdata)); //TCPIP 端口读取数据
EnterCriticalSection(CS); //进入多线程临界区，防止重复进入
setlength(online, high(online) + 2); //设置公共变量缓冲区大小
online[high(online)] := userdata; //把读取的数据进行 传递给公共变量
//更新显示
with onlineview.Items.Add do //显示到View 控件上
begin
Caption := userdata.username; 名字
imageindex := userdata.whatdoing; 图片
subitems.Add(userdata.email);
end;
LeaveCriticalsection(CS); //释放临界区

[jingtuzhong]

谢谢，谢谢，