QFtp的list 命令 发射 listInfo信号，
执行序列
list ->commandStared
listInfo(file1)
listInfo(file2)
...
commandFinished
可以在commandStarted/Finished中监控 commandid 识别命令执行。
但是 执行get命令中 地一个get启动时发射 commandstart 得到 commandid=QFt::get
但是每个get执行后检测不到commandfinished中 commandid==QFT:get 命令
只在最后一个get执行后，监控到 commandfinished中的 commandid==QFTP::get命令
原因：见以下链接
https://stackoverflow.com/questions/23698520/qftp-get-never-emits-commandfinished
I am too late to reply, but it still may help others.
In void Ftp::commandFinished(int i, bool error) it is always better to check for QFtp::None option also, since if your last command is get and when commandFinished() slot gets called then if (ftp->currentCommand() == QFtp::Get) will not be able to identify the last command, since your current command may not be get because it is already finished.
You can also check with id as if(ftp->currentCommand() == QFtp::Get || 1 == id)
commandfiished 发送的过早，没有捕捉到 命令号。但可以在ftp->currenCommand==QFtp::Get 得到 该消息