Construct a dynamic object from another object that has dictionary<string, object> property with varying key-value pairs

Question

I'm trying to collate the properties from an existing object that contains some static properties. The object also contains a Dictionary with key value pairs. These key value pairs should be dynamically added as properties to the new object I'm creating.

This is the set up for source object:

public class MyClass
{
    public string PropA { get; set; }
    public string PropB { get; set; }
    public string PropC { get; set; }

    public IDictionary<string, NameValuePair> PropD { get; set; }
}

public class NameValuePair
{
    public string Name { get; set; }
    public string Value { get; set; }
}

---

This is where I create a list of the objects:

void Main()
{

    var data = new List<MyClass>
    {
        new MyClass {PropA = "A1", PropB = "B1", PropC = "C1", PropD = new Dictionary<string, NameValuePair>
        {
            { "Code11", new NameValuePair {Name = "PropD11", Value = "V11"}},
            { "Code12", new NameValuePair {Name = "PropD12", Value = "V12"}}
        }},
        new MyClass {PropA = "A2", PropB = "B2", PropC = "C2", PropD = new Dictionary<string, NameValuePair>
        {
            { "Code21", new NameValuePair {Name = "PropD21", Value = "V21"}},
            { "Code22", new NameValuePair {Name = "PropD22", Value = "V22"}},
        }},
        new MyClass {PropA = "A3", PropB = "B3", PropC = "C3", PropD = new Dictionary<string, NameValuePair>
        {
            { "Code12", new NameValuePair {Name = "PropD12", Value = "V31"}},
            { "Code21", new NameValuePair {Name = "PropD21", Value = "V32"}},
        }},
    };
//Extract column names from static properties
    var staticColumns = typeof(MyClass).GetProperties().Where(n => n.PropertyType == typeof(string)).Select(p => p.Name);

//Extract column names from the dictionary
    var dynamicColumns = data.Where(c => c.PropD.Any()).Select(c => c.PropD).SelectMany(c => c.Values.Select(v => v.Name)).Distinct().ToList();

//Combine to get a new list of columns 
    var columns = staticColumns.Union(dynamicColumns);

//Create object using columns

//Copy values from data to construct the new object.    
}

I need help with logic to construct an object at runtime, that has the structure as below and the data correctly mapped.

PropA    PropB    PropC  PropD11  PropD12  PropD21  PropD22
------------------------------------------------------------
A1       B1       C1     V11      V12       
A2       B2       C2                       V21      V22
A3       B3       C3              V31      V32  

Answer 1

Assuming your possible property names are static, here is an answer class:

public class AnsClass {
    public string PropA { get; set; }
    public string PropB { get; set; }
    public string PropC { get; set; }

    public string PropD11 { get; set; }
    public string PropD12 { get; set; }
    public string PropD21 { get; set; }
    public string PropD22 { get; set; }
}

And here is a LINQ statement to create a list of them:

var ans = data.Select(d => new AnsClass {
                    PropA = d.PropA,
                    PropB = d.PropB,
                    PropC = d.PropC,
                    PropD11 = d.PropD.Values.FirstOrDefault(v => v.Name == "PropD11")?.Value,
                    PropD12 = d.PropD.Values.FirstOrDefault(v => v.Name == "PropD12")?.Value,
                    PropD21 = d.PropD.Values.FirstOrDefault(v => v.Name == "PropD21")?.Value,
                    PropD22 = d.PropD.Values.FirstOrDefault(v => v.Name == "PropD22")?.Value,
                })
                .ToList();

If the members of PropD are dynamic, you can use the following to create ExpandoObjects but you are really better off just using MyClass the way it is - it has the best design for this already.

var ans2 = new List<dynamic>();
foreach (var d in data) {
    dynamic eo = new ExpandoObject();
    eo.PropA = d.PropA;
    eo.PropB = d.PropB;
    eo.PropC = d.PropC;
    var deo = (IDictionary<string,object>)eo;
    foreach (var dp in d.PropD.Values)
        deo.Add(dp.Name, dp.Value);
    ans2.Add(eo);
}