c# - 将具有键值属性的对象 [] 映射到对象的属性，而无需使用巨大的讨厌开关

Question

我有一个键值对象数组。

public class KeyValueStore
{
   public string Key {get;set;}
   public string Value {get;set;}
}

这个数组存储我试图像这样填充的对象的值:

public class Customer
{
   public string Name {get;set;}
   public string Country {get;set}
}

所以我想将这些键从 KeyValueStore 映射到客户属性

public Customer TransformToCustomer(KeyValueStore[] keyValueStore)
{
    var customer = new Customer();

    foreach (var keyValue in keyValueStore)
    {
        switch (keyValue.Key)
        {
            case "Name":
                customer.Name = keyValue.Value;
                break;
            case "Cntry":
                customer.Country = keyValue.Value;
                break;
        }
    }

    return customer;
}

有更好的方法吗？

Answer 1

是的，假设目标类型有一个无参数的构造函数，您可以编写一个泛型方法来执行此操作:

public T CreateAndPopulate<T>(IEnumerable<KeyValueStore> propStore,
                              IDictionary<string, string> mapping = null) 
                             where T:class,new()
{

    T item=new T();
    var type=typeof(T);
    foreach(var kvs in propStore)
    {
        var propName = kvs.Key;
        propName = mapping !=null && mapping.ContainsKey(propName) 
                       ? mapping[propName] 
                       : propName;
        var prop = type.GetProperty(propName);
        if(prop == null) //does the property exist?
        {
            continue;
        }
        var propMethodInfo = prop.GetSetMethod();
        if(propMethodInfo == null) //does it have a set method?
        {
            continue;
        }
        propMethodInfo.Invoke(item, new[]{ kvs.Value });
    }
    return item;
}

并使用它:

IEnumerable<KeyValueStore> propStore = new KeyValueStore[]{
    new KeyValueStore{ Key = "Name", Value = "John" },
    new KeyValueStore{ Key = "Cntry", Value = "UK" }};
var mapping = new Dictionary<string,string>{{ "Cntry", "Country" }};

var customer = CreateAndPopulate<Customer>(propStore, mapping);