AS3 cast String as an Object

I hope this helps . You're misusing Cast.
First, here:

IEnumerable<string> items = strings.Cast<object>();

// Cast to IEnumerabe<object> then convert to List<object>
ProcessCollectionDynamicallyWithReflection(strings.Cast<object>().ToList());

will be helpful for those in need You can simply write a helper method that ensures the type of the value prior to executing the predicate. Something like:

    public static bool CompareToObject<TSource>(TSource left, object right, Func<TSource, TSource, bool> predicate)
    {
        if (right is TSource)
            return predicate(left, (TSource)right);
        else
            return false;
    }

entityProps.Where(p => CompareToObject(p[propName], value, (x, y) => x == y));

To fix the issue you can do You probably can't, because it's a string. It's not a cProduct (whatever that is - consider following .NET naming conventions and naming it Product instead).
Now you could do this if you had a explicit conversion operator in cProduct to create an instance from a string.

Product product = new Product(objPro.CommandArgument);

Product product = Product.Parse(objPro.CommandArgument);

will help you I have the following Hibernate Object implemented: , My picklist component:

<p:pickList id="pickList" 
  value="#   {reportConfiguratorBean.dualListVars}"
  var="cRVariable" 
  itemValue="#{cRVariable}" 
  itemLabel="#{cRVariable.varName}"
  converter="cRVariableConverter"
  Ajax="false" >
  <f:facet name="sourceCaption">Available Variables</f:facet>
  <f:facet name="targetCaption">Associated Variables</f:facet>              
</p:pickList>

public Object getAsObject(FacesContext context, UIComponent component, String value) {
    Long varId = Long.parseLong(value.trim());  
    List<CRVariable> cRVariables = mybean.getCRVariables();

    for (CRVariable cRVariable:cRVariables) {
        if(cRVariable.getVarId().compareTo(varId)==0){
            return cRVariable;
        }
    }

    return null;    
}

This might help you I gave your sample a try and noticed that the startPrt parameter is actually being received as an Array of Dictionary(string, object). Hence, if you make the AJAX call like this:

var hDate = [];
hDate.push({ key: "Name", value: Name });
hDate.push({ key: "City", value: City });
hDate.push({ key: "Country", value: Country });
hDate.push({ key: "SelctedClass", value: selectedRC });

$.ajax({
    contentType: 'application/json; charset=utf-8',
    url: 'MyPage.aspx/AddNewRecord',
    type: 'POST',
    data: JSON.stringify({ startPrt: hDate }),
    success: success, // success callback
    error: error // error callback
});

[WebMethod]
public static void AddNewRecord(object startPrt)
{
    var dict = new Dictionary<string, object>();
    foreach (Dictionary<string, object> pair in (Array)startPrt)
        dict.Add((string)pair["key"], pair["value"]);
}