Get property value from C# dynamic object by string (reflection?)

Question

Imagine that I have a dynamic variable:

dynamic d = *something*

Now, I create properties for d which I have on the other hand from a string array:

string[] strarray = { 'property1','property2',..... }

I don't know the property names in advance.

How in code, once d is created and strarray is pulled from DB, can I get the values?

I want to get d.property1 , d.property2.

I see that the object has a _dictionary internal dictionary that contains the keys and the values, how do I retrieve them?

Answer 1

I don't know if there's a more elegant way with dynamically created objects, but using plain old reflection should work:

var nameOfProperty = "property1";
var propertyInfo = myObject.GetType().GetProperty(nameOfProperty);
var value = propertyInfo.GetValue(myObject, null);

GetProperty will return null if the type of myObject does not contain a public property with this name.

---

EDIT: If the object is not a "regular" object but something implementing IDynamicMetaObjectProvider, this approach will not work. Please have a look at this question instead:

• How do I reflect over the members of dynamic object?

Answer 2

I know this is an old Question, but i would like to share my Solution: This works same for both Dynamic and 'non-dynamic' data:

var _RowData = mydata[RowIndex]; //<- Whole Row of Data
//Locate and Load the Field Property by Name:
var propertyInfo = System.ComponentModel.TypeDescriptor.
    GetProperties((object)_RowData ).   
    Find("field_name", true);

string FieldName = propertyInfo.Name;
object FieldValue = propertyInfo.GetValue(_dataRow);

Tested over Dynamic data converted from a JSON file using Newtonsoft.Json.

Answer 3

Say you have anonymous type in service result.Value, with class errorCode and property ErrorMessage, and needed to get the value of ErrorMessage, could get it in one-liner like this using dynamic:

var resVal = (dynamic)result.Value; var errMsg = resVal.GetType().GetProperty("errorCode").GetValue(resVal, null).ErrorMessage;

Answer 4

Getting value data from a dynamic objects using property(string).

var nameOfProperty = "chairs";
var propertyInfo = model.assets.GetType().GetField(nameOfProperty).GetValue(model.assets);

Answer 5

you can try like this:

d?.property1 , d?.property2

I have tested it and working with .netcore 2.1

Answer 6

Use the following code to get Name and Value of a dynamic object's property.

dynamic d = new { Property1= "Value1", Property2= "Value2"};

var properties = d.GetType().GetProperties();
foreach (var property in properties)
{
    var PropertyName=property.Name; 
//You get "Property1" as a result

  var PropetyValue=d.GetType().GetProperty(property.Name).GetValue(d, null); 
//You get "Value1" as a result

// you can use the PropertyName and Value here
 }

Answer 7

IF d was created by Newtonsoft you can use this to read property names and values:

    foreach (JProperty property in d)
    {
        DoSomething(property.Name, property.Value);
    }

Answer 8

Thought this might help someone in the future.

If you know the property name already, you can do something like the following:

[HttpPost]
[Route("myRoute")]
public object SomeApiControllerMethod([FromBody] dynamic args){
   var stringValue = args.MyPropertyName.ToString();
   //do something with the string value.  If this is an int, we can int.Parse it, or if it's a string, we can just use it directly.
   //some more code here....
   return stringValue;
}

Answer 9

string json = w.JSON;

var serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new[] { new DynamicJsonConverter() });

DynamicJsonConverter.DynamicJsonObject obj = 
      (DynamicJsonConverter.DynamicJsonObject)serializer.Deserialize(json, typeof(object));

Now obj._Dictionary contains a dictionary. Perfect!

This code must be used in conjunction with Deserialize JSON into C# dynamic object? + make the _dictionary variable from "private readonly" to public in the code there

Answer 10

Did you see ExpandoObject class?

Directly from MSDN description: "Represents an object whose members can be dynamically added and removed at run time."

With it you can write code like this:

dynamic employee = new ExpandoObject();
employee.Name = "John Smith";
((IDictionary<String, Object>)employee).Remove("Name");

Answer 11

Hope this would help you:

public static object GetProperty(object o, string member)
{
    if(o == null) throw new ArgumentNullException("o");
    if(member == null) throw new ArgumentNullException("member");
    Type scope = o.GetType();
    IDynamicMetaObjectProvider provider = o as IDynamicMetaObjectProvider;
    if(provider != null)
    {
        ParameterExpression param = Expression.Parameter(typeof(object));
        DynamicMetaObject mobj = provider.GetMetaObject(param);
        GetMemberBinder binder = (GetMemberBinder)Microsoft.CSharp.RuntimeBinder.Binder.GetMember(0, member, scope, new CSharpArgumentInfo[]{CSharpArgumentInfo.Create(0, null)});
        DynamicMetaObject ret = mobj.BindGetMember(binder);
        BlockExpression final = Expression.Block(
            Expression.Label(CallSiteBinder.UpdateLabel),
            ret.Expression
        );
        LambdaExpression lambda = Expression.Lambda(final, param);
        Delegate del = lambda.Compile();
        return del.DynamicInvoke(o);
    }else{
        return o.GetType().GetProperty(member, BindingFlags.Public | BindingFlags.Instance).GetValue(o, null);
    }
}

Answer 12

This will give you all property names and values defined in your dynamic variable.

dynamic d = { // your code };
object o = d;
string[] propertyNames = o.GetType().GetProperties().Select(p => p.Name).ToArray();
foreach (var prop in propertyNames)
{
    object propValue = o.GetType().GetProperty(prop).GetValue(o, null);
}