QLineEdit* lineEdit = new QLineEdit(this);
    lineEdit->setContextMenuPolicy(Qt::NoContextMenu);//設定無右鍵選單
    lineEdit->setPlaceholderText(QString::fromLocal8Bit("密碼"));//設定密碼提示
    lineEdit->setEchoMode(QLineEdit::Password);//設定密碼隱藏
    lineEdit->setStyleSheet("QLineEdit{border-width:1px;border-radius:4px;font-size:12px;color:black;border:1px solid gray;}"
 

        "QLineEdit:hover{border-width:1px;border-radius:4px;font-size:12px;color:black;border:1px solid rgb(70,200,50);}");
    lineEdit->setMaxLength(16);//設定最大長度16位