POCO到对象映射C＃ [英] POCO to Object Mapping C#

问题描述

我正在努力解决这个问题，我知道我不应该这样做;但出于某种原因，我现在只是被精神上阻止了。



我有3个课程，我的POCO和两个第三方课程，我试图将第三方类对象的属性值映射到我的一个元素POCO。（我用它作为中介来更新数据库，以及通过WCF的UI）[也许我使用的是一种糟糕的方法，但我对此并不确定]。请参阅下面的代码及其下面的说明。

I am struggling with this concept and I know I should not be; but for some reason I'am just mentally blocked right now.

I have 3 classes, my POCO and two 3rd Party classes and I am trying to map the property value of a 3rd party class object to one of the elements in my POCO .(which I am using as an Intermediary to update a database, and a UI with via WCF) [Maybe I am using a bad approach but I am not sure on this]. See the code below along with the explanatory below it.

public List<Machine> Machines;
public List<Item> MachineItems;

public class Machine : IMachine
{
 [DataMember]
 double SensorA {get; set;}

 [DataMember]
 double SensorB {get; set;}

 [DataMember]
 string Sytem1 {get; set;}
}
public class ItemValue : Item
{
 object value;
}
public class Item
{
 object clientID;
 System.Type sysType;
}
OnNewlyReadValues(ItemValue[] itemValues)
{
   // each itemValue in itemValues represents a property
   // in the POCO .
   // itemValues May contain one itemValue or all itemValue
   // that represent the values in the POCO.
   // Determine if itemValue is for which Machine.PropertyName
   // property SensorA  (or any of the properties)
   // Machine.Property = itemValue.Value;

}

我只能修改机器类，其他两个类是belo ng到第三方库，期望传递这两种类型; [也许我不知道怎么解决这个问题]。



我将Item实例化为带有参数clientID等的新项目所以我有了clientID并将此Item对象传递给第三方库。



OnNewlyReadValues是来自第三方库的事件，并且具有ItemValue []的参数 - 每个itemValue对象都有一个名为Value的属性，并代表我的一个属性POCO。 ItemValue还有我传递给第三方库的myItem的clientID。



我试图将这个ItemValue.Value属性映射到POCO，效率非常高方式物品不会经常改变，但Value属性会。



如上面的例子，最好的方法是什么？感谢任何示例，ItemValue将clientID作为与我的Item.ClientID匹配的标识符。

I can only Modify Machine Class, the other two classes belong to a 3rd party library, which expects these two types to be passed in; [Maybe I do not know enough to know how to get around that].

I instantiate the Item as a new Item with parameters clientID etc. so I have the clientID and pass this Item object on to the 3rd party Library.

The OnNewlyReadValues is an event from the 3rd party library and has arguments of ItemValue[] - each itemValue object has a property named "Value" and represents a Property in my POCO. ItemValue also has my clientID from myItem that I passed to the 3rd party library.

I am trying to map this ItemValue.Value property to the POCO, in a very efficient manner the Items will not change often, but the Value property will.

What is the best way to do this , given the example above ? Any examples are appreciated,, ItemValue has the clientID as an Identifier which matches my Item.ClientID.

推荐答案

从您的解释我知道您可以将clientID映射到财产。它仍然感觉像魔术一样，我可能会遗漏一些东西，但我们假设你可以进行翻译。



你对构建字典的想法是正确的。它应该是一个setter字典：

From your explanation I understand you are able to map a clientID to a property. It still feels like magic and it's possible that I'm missing something but let's assume you can do the translation.

Your idea about building a dictionary is correct. It should be a dictionary of setters:

public Dictionary<object, Action<machine,object>> setters = new Dictionary<object, Action<machine,object>>
{
    {1, (m,v) => m.SensorA = (double)v},
    {2, (m,v) => m.SensorB = (double)v},
    {3, (m,v) => m.System1 = (string)v},
};

关键是clientId。该值是一个setter - 一个采取POCO和项目值并执行任务的动作。



这可能看起来像是一种矫枉过正，但会让事情成为现实在事件处理程序中更容易：

The key is the clientId. The value is a the setter - an action which takes the POCO and the item value and does the assignment.

This might seem as an overkill but will make things it a lot easier in the event handler:

public void OnNewlyReadValues(ItemValue[] itemValues)
{
    var machine = new Machine();
    
    foreach(var itemValue in itemValues)
    {
        var setter = setters[itemValue.clientID];
        setter(machine, itemValue.value);
    }
    
    // your POCO is initialized
}

根据clientID检索设置器并将其应用于您的POCO和项目值。



编辑 - 多台机器

如果我理解正确，那么你想在客户端类的生命周期中使用相同的机器实例。 br />


创建一个封装客户端ID的类。在您的第三方库中，clientID是一个对象，因此您可以在那里放置任何内容：

Based on the clientID you retrieve the setter and apply it on your POCO and item value.

Edit - multiple machines
If I understand you correctly then you want to use the same Machine instance trough the life of the client class.

Create a class that will encapsulate client ID. In your third party library the clientID is an object so you can put whatever you want there:

public class ClientId
{
    public Machine Machine { get; set; }
    public int SetterKey { get; set; }
}

SetterKey是字典中的键。实际上，您可以将其更改为简单数组，然后SetterKey将成为SetterIndex。初始化将如下所示：

The SetterKey is the key in the dictionary. Actually you can change that into simple array and SetterKey will then become SetterIndex. You initialization will look something like this:

Machines = new List<Machine>
{
    new Machine(),
    new Machine()
};

MachineItems = new List<Item>
{
    new Item { clientID = new ClientId { Machine = Machines[0], SetterKey = 1 }},
    new Item { clientID = new ClientId { Machine = Machines[0], SetterKey = 2 }},
    new Item { clientID = new ClientId { Machine = Machines[0], SetterKey = 3 }},
    new Item { clientID = new ClientId { Machine = Machines[1], SetterKey = 1 }},
    new Item { clientID = new ClientId { Machine = Machines[1], SetterKey = 2 }},
    new Item { clientID = new ClientId { Machine = Machines[1], SetterKey = 3 }},
};

再次这一切都将使事件处理程序中的代码更容易。您将Machine实例直接嵌入clientID中。

Again all this is will make the code in the event handler much easier. You have the Machine instance embedded directly in the clientID.

public void OnNewlyReadValues(ItemValue[] itemValues)
{
    foreach(var itemValue in itemValues)
    {
        var clientId = (ClientId) itemValue.clientID;	
        var setter = setters[clientId.SetterKey];
        setter(clientId.Machine, itemValue.value);
    }
}

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