GetCachedChildren not working

I am new to UIA and i am having some problem in properly caching my elements. The thing is my GetCachedChildren function always returns a NULL for my children array. And the reason behind it is i think me. Because i am having a hard time understanding which of the elements get cached or how to properly cache them.

IUIAutomationCacheRequest* CacheRequest = NULL;
        hr = Auto->CreateCacheRequest(&CacheRequest);
        if (SUCCEEDED(hr))
        {
            hr = CacheRequest->AddProperty(UIA_BoundingRectanglePropertyId);
            if (SUCCEEDED(hr))
            {
                hr = CacheRequest->AddProperty(UIA_NamePropertyId);
                if (SUCCEEDED(hr))
                {
                    hr = CacheRequest->AddProperty(UIA_LocalizedControlTypePropertyId);
                    if (SUCCEEDED(hr))
                    {
                        hr = CacheRequest->AddPattern(UIA_ButtonControlTypeId);
                    }
                }
            }
        }

        IUIAutomationCondition* ButtonCon = NULL;
        IUIAutomationElementArray* ButtonArray = NULL;
        IUIAutomationElement* Button = NULL;
        VARIANT var;
        var.vt = VT_I4;
        var.lVal = UIA_ButtonControlTypeId;
        Auto->CreatePropertyCondition(UIA_ControlTypePropertyId, var, &ButtonCon);
        if (ButtonCon == NULL)
        {
            return;
        }

        Parent->FindAllBuildCache(TreeScope_Children, ButtonCon, CacheRequest, &ButtonArray);

In the next iteration when i call
Parent->GetCachedChildren(&Element);
 It doesnt work.


Now i am not sure how to retrieve these cached elements? whenever i try to get elements via getcachedchildren the array is always empty? Can someone at least give me an idea (theoretically) as to how to properly cache the elements? Because i am finding it really hard to understand what the sequence of my actions will be in order to peroperly cache and retrieve the elements and their properties.