重构了连接数据库、设置设备名的代码，封装为类

deviceAPI.h

@@ -0,0 +1,51 @@
+#ifndef DEVICEAPI_H
+#define DEVICEAPI_H
+
+#include <QString>
+#include <QSqlQuery>
+#include <databaseAPI.h>
+
+class Device
+{
+private:
+    bool connected = false;
+    bool depositAllowed = false;
+    QString name = QString("未指定设备名");
+
+public:
+    bool is_connected()
+    {
+        return connected;
+    }
+
+    bool is_depositAllowed()
+    {
+        return depositAllowed;
+    }
+
+    void setDevice(QString name, Database *db)
+    {
+        QSqlQuery query(db->getDatabase());
+        QString sql = QString("select * from device where `name` = '%1';").arg(name);
+        query.exec(sql);
+        if (query.next())
+        {
+            connected = true;
+            this->name = name;
+            depositAllowed = query.value(2).toBool();
+        }
+        else
+        {
+            connected = false;
+            depositAllowed = false;
+        }
+    }
+
+    QString getName()
+    {
+        if (connected) return name;
+        else return QString("未指定设备名");
+    }
+};
+
+#endif // DEVICEAPI_H