c#代码重构与迭代（一）——循环代码的优化

foreach (var item in list)
          {
              Devices _Device = DevicesLogic.GetInstance().GetDevices(item.DeviceID);
              string addr = item.Address;
              if (addr.Trim() == "")
              {
                  addr = LocationAPI.GetAddressNew(item.OLat, item.OLng);
              }
              var ur = UserGroupRelationLogic.GetInstance().GetDeviceGroup(item.DeviceID, model.UserID);
              var profile = PersonProfileLogic.GetInstance().GetProfileByDevice(item.DeviceID);
              string Nickname = "";
              if (profile != null)
                  Nickname = profile.Nickname ?? "";
              if (ur != null && _Device != null && model.UserID != _Device.UserID && !ur.NickName.IsNullOrEmpty())
              {
                  Nickname = ur.NickName;
              }
         }

var deviceLogic = DevicesLogic.GetInstance();
            var userGroupRelationLogic = UserGroupRelationLogic.GetInstance();
            var personProfileLogic = PersonProfileLogic.GetInstance();
 
            Parallel.ForEach(list, (item) =>
            {
                var deviceId = item.DeviceID;
                var device = deviceLogic.GetDevices(deviceId);
                if (device == null || model.UserID == device.UserID) return;
 
                var address = string.IsNullOrWhiteSpace(item.Address) ? LocationAPI.GetAddressNew(item.OLat, item.OLng) : item.Address;
 
                var deviceGroup = userGroupRelationLogic.GetDeviceGroup(deviceId, model.UserID);
                var nickname = deviceGroup != null && !string.IsNullOrWhiteSpace(deviceGroup.NickName)
                    ? deviceGroup.NickName
                    : (personProfileLogic.GetProfileByDevice(deviceId)?.Nickname ?? "");
 
            });

优化说明：

使用Parallel.ForEach并行循环，这样能够同时处理多个元素，提高代码执行效率；
并行循环还需要保证线程安全，所以在循环体内部不要修改共享资源；
优化方式与之前相同，对列表中每个元素进行逐一处理，并简化代码逻辑。
将DevicesLogic、UserGroupRelationLogic和PersonProfileLogic实例化放在循环外部，避免在每次迭代中重复实例化；
使用var关键字提高代码可读性和简洁性；
简化addr变量赋值逻辑；
改善条件语句if(ur != null && _Device != null && model.UserID != _Device.UserID && !ur.NickName.IsNullOrEmpty())的结构；
简化deviceName变量赋值逻辑。