开发者

List<T> to a Dictionary

开发者 https://www.devze.com 2023-01-23 21:56 出处:网络
I have a List<CustomObject> which has 3 properties A,B,C and what I need is to transform this List to a Dictionary so the result looks like

I have a List<CustomObject> which has 3 properties A,B,C and what I need is to transform this List to a Dictionary so the result looks like

Dictionary<string,object>
(Property n开发者_StackOverflow社区ame) A = Value of A
(Property name) B = Value of B
(Property name) C = Value of C

Pls suggest...


CustomObject instance = new CustomObject();
var dict = instance.GetType().GetProperties()
    .ToDictionary(p => p.Name, p => p.GetValue(instance, null));


I found the code :) Originally from here.

static T CreateDelegate<T>(this DynamicMethod dm) where T : class
{
  return dm.CreateDelegate(typeof(T)) as T;
}

static Dictionary<Type, Func<object, Dictionary<string, object>>> cache = 
   new Dictionary<Type, Func<object, Dictionary<string, object>>>();

static Dictionary<string, object> GetProperties(object o)
{
  var t = o.GetType();

  Func<object, Dictionary<string, object>> getter;

  if (!cache.TryGetValue(t, out getter))
  {
    var rettype = typeof(Dictionary<string, object>);

    var dm = new DynamicMethod(t.Name + ":GetProperties", rettype, 
       new Type[] { typeof(object) }, t);

    var ilgen = dm.GetILGenerator();

    var instance = ilgen.DeclareLocal(t);
    var dict = ilgen.DeclareLocal(rettype);

    ilgen.Emit(OpCodes.Ldarg_0);
    ilgen.Emit(OpCodes.Castclass, t);
    ilgen.Emit(OpCodes.Stloc, instance);

    ilgen.Emit(OpCodes.Newobj, rettype.GetConstructor(Type.EmptyTypes));
    ilgen.Emit(OpCodes.Stloc, dict);

    var add = rettype.GetMethod("Add");

    foreach (var prop in t.GetProperties(
      BindingFlags.Instance |
      BindingFlags.Public))
    {
      ilgen.Emit(OpCodes.Ldloc, dict);

      ilgen.Emit(OpCodes.Ldstr, prop.Name);

      ilgen.Emit(OpCodes.Ldloc, instance);
      ilgen.Emit(OpCodes.Ldfld, prop);
      ilgen.Emit(OpCodes.Castclass, typeof(object));

      ilgen.Emit(OpCodes.Callvirt, add);
    }

    ilgen.Emit(OpCodes.Ldloc, dict);
    ilgen.Emit(OpCodes.Ret);

    cache[t] = getter = 
      dm.CreateDelegate<Func<object, Dictionary<string, object>>>();
  }

  return getter(o);
}

For given type:

class Foo
{
  public string A {get;}
  public int B {get;}
  public bool C {get;}
}

It produces a delegate equivalent to:

(Foo f) => new Dictionary<string, object>
  {
    { "A", f.A },
    { "B", f.B },
    { "C", f.C },
  };

Disclaimer: Looking at the code now (without testing) there may need to be special handling for valuetypes (instead of just the castclass). Exercise for the reader.


If I understand correctly what you want to do, you have to use reflrecion on CustomObject to get the property names then simply create the dictionary:

dic.add(propertyName, value);

0

精彩评论

暂无评论...
验证码 换一张
取 消