"'object' does not contain a definition for 'property' and no extension method 'property' accepting a first argument of type 'object' could be found"

Question

I've created a simple class that is a descendant of DynamicObject:

public class DynamicCsv : DynamicObject
{

    private Dictionary<string, int> _fieldIndex;
    private string[] _RowValues;

    internal DynamicCsv(string[] values, Dictionary<string, int> fieldIndex)
    {
        _RowValues = values;
        _fieldIndex = fieldIndex;
    }

    internal DynamicCsv(string currentRow, Dictionary<string, int> fieldIndex)
    {
        _RowValues = currentRow.Split(',');
        _fieldIndex = fieldIndex;
    }

    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        result = null;
        dynamic fieldName = binder.Name.ToUpperInvariant();
        if (_fieldIndex.ContainsKey(fieldName))
        {
            result = _RowValues[_fieldIndex[fieldName]];
            return true;
        }
        return false;
    }

    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        dynamic fieldName = binder.Name.ToUpperInvariant();
        if (_fieldIndex.ContainsKey(fieldName))
        {
            _RowValues[_fieldIndex[fieldName]] = value.ToString();
            return true;
        }
        return false;
    }

}

I use the descendant object by doing the following:

    protected string[] _currentLine;
    protected Dictionary<string, int> _fieldNames;
...
                _fieldNames = new Dictionary<string, int>();
...
                _CurrentRow = new DynamicCsv(_currentLine, _fieldNames);

When I try to use the _CurrentRow with dot notation:

int x = _CurrentRow.PersonId;

I get the following error message:

"'object' does not contain a definition for 'property' and no extension method 'property' accepting a first argument of type 'object' could be found"

I can resolve the property in the immediate window using VB without any issues though:

? _CurrentRow.PersonId

Answer 1

it looks like _CurrentRow is typed to object but that you want dynamic lookup to occur on it. If that's the case then you need to change the type to dynamic

dynamic _CurrentRow;

Answer 2

You're not showing the declaration of _CurrentRow. It should be declared as

dynamic _CurrentRow in order to have the dynamic behavior.