动态添加C＃属性在运行时 [英] Dynamically Add C# Properties at Runtime

问题描述

我知道有一些解决这个问题，但答案通常沿着推荐的参数的字典或集合，这并不在我的情况下工作的行跟进。

I know there are some questions that address this, but the answers usually follow along the lines of recommending a Dictionary or Collection of parameters, which doesn't work in my situation.

我使用的是通过反射的作品做大量的聪明的事情与属性的对象库。这适用于定义的类，以及动态类。我需要进一步采取这一步骤，并做沿着这些路线的内容：

I am using a library that works through reflection to do lots of clever things with objects with properties. This works with defined classes, as well as dynamic classes. I need to take this one step further and do something along these lines:

public static object GetDynamicObject(Dictionary<string,object> properties) {
    var myObject = new object();
    foreach (var property in properties) {
        //This next line obviously doesn't work... 
        myObject.AddProperty(property.Key,property.Value);
    }
    return myObject;
}

public void Main() {
    var properties = new Dictionary<string,object>();
    properties.Add("Property1",aCustomClassInstance);
    properties.Add("Property2","TestString2");

    var myObject = GetDynamicObject(properties);

    //Then use them like this (or rather the plug in uses them through reflection)
    var customClass = myObject.Property1;
    var myString = myObject.Property2;

}

图书馆正常工作与动态变量的类型，性质与手动分配。不过，我不知道有多少或哪些属性将被添加事先

The library works fine with a dynamic variable type, with properties assigned manually. However I don't know how many or what properties will be added beforehand.

推荐答案

让你在拍摄ExpandoObject看看？

Have you taken a look at ExpandoObject?

请参见：<一href=\"http://blogs.msdn.com/b/csharpfaq/archive/2009/10/01/dynamic-in-c-4-0-introducing-the-expandoobject.aspx\">http://blogs.msdn.com/b/csharpfaq/archive/2009/10/01/dynamic-in-c-4-0-introducing-the-expandoobject.aspx

从MSDN：

该ExpandoObject类，您可以添加并在运行时删除其实例的成员，还可以设置和获取这些成员的值。此类支持动态绑定，从而使您能够使用标准语法像sampleObject.sampleMember反而更复杂的语法像sampleObject.GetAttribute（sampleMember）。

The ExpandoObject class enables you to add and delete members of its instances at run time and also to set and get values of these members. This class supports dynamic binding, which enables you to use standard syntax like sampleObject.sampleMember instead of more complex syntax like sampleObject.GetAttribute("sampleMember").

让你做很酷的事情，如：

Allowing you to do cool things like:

dynamic dynObject = new ExpandoObject();
dynObject.SomeDynamicProperty = "Hello!";
dynObject.SomeDynamicAction = (msg) =>
    {
        Console.WriteLine(msg);
    };

dynObject.SomeDynamicAction(dynObject.SomeDynamicProperty);

---

根据您的实际code你可能会更感兴趣的是：

---

Based on your actual code you may be more interested in:

public static dynamic GetDynamicObject(Dictionary<string, object> properties)
{
    return new MyDynObject(properties);
}

public sealed class MyDynObject : DynamicObject
{
    private readonly Dictionary<string, object> _properties;

    public MyDynObject(Dictionary<string, object> properties)
    {
        _properties = properties;
    }

    public override IEnumerable<string> GetDynamicMemberNames()
    {
        return _properties.Keys;
    }

    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        if (_properties.ContainsKey(binder.Name))
        {
            result = _properties[binder.Name];
            return true;
        }
        else
        {
            result = null;
            return false;
        }
    }

    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        if (_properties.ContainsKey(binder.Name))
        {
            _properties[binder.Name] = value;
            return true;
        }
        else
        {
            return false;
        }
    }
}

这样，你只需要：

That way you just need:

var dyn = GetDynamicObject(new Dictionary<string, object>()
    {
        {"prop1", 12},
    });

Console.WriteLine(dyn.prop1);
dyn.prop1 = 150;

从DynamicObject推导可以让你拿出你自己的策略来处理这些动态成员的请求，提防出现在这里的怪物：编译器将不会能验证你的很多动态调用的，你不会得到智能感知，所以只要记住这一点。

Deriving from DynamicObject allows you to come up with your own strategy for handling these dynamic member requests, beware there be monsters here: the compiler will not be able to verify a lot of your dynamic calls and you won't get intellisense, so just keep that in mind.

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