private bool GroupValueEquals(HeaderItemWrapper headerWrapperA, int itemIndexB)
{
if (itemIndexB < 0)
{
return(false);
}
var headerWrapperB = GetGroupHeader(itemIndexB);
return(headerWrapperA != null && headerWrapperB != null && Equals(headerWrapperA.GroupingValue, headerWrapperB.GroupingValue));
}
private FrameworkElement GetOrCreateGroupHeader(int itemIndex, HeaderItemWrapper headerWrapper, FrameworkElement lvParent, out bool newCreated)
{
if (headerWrapper.HeaderItem != null)
{
newCreated = false;
return(headerWrapper.HeaderItem);
}
var headerItem = new GroupHeaderItem()
{
FirstItem = _items[itemIndex],
GroupingValue = headerWrapper.GroupingValue
};
newCreated = true;
var result = PrepareGroupHeader(headerItem, lvParent);
headerItem.LogicalParent = result;
headerWrapper.HeaderItem = result;
return(result);
}
private HeaderItemWrapper GetGroupHeader(int itemIndex)
{
var headerWrapper = _materializedGroupHeaders[itemIndex];
if (headerWrapper != null)
{
return(headerWrapper);
}
if (_groupingValueProvider != null)
{
headerWrapper = new HeaderItemWrapper(_groupingValueProvider.GetGroupingValue(_items[itemIndex]));
}
else
{
// to get the grouping value of the item we use a dummy header item and apply the DataContext and group value binding to it
if (_getValueGroupHeader == null)
{
_getValueGroupHeader = new GroupHeaderItem();
var dd = new SimplePropertyDataDescriptor(_getValueGroupHeader, typeof(GroupHeaderItem).GetProperty("GroupingValue"));
var binding = MpfCopyManager.DeepCopyCutLVPs(_groupPropertyBinding);
binding.SetTargetDataDescriptor(dd);
binding.Activate();
}
_getValueGroupHeader.DataContext = new BindingExtension()
{
Source = _items[itemIndex],
Path = "."
};
// then we create the actual header item and apply the value to it
headerWrapper = new HeaderItemWrapper(_getValueGroupHeader.GroupingValue);
// finally cleanup the datacontext binding
MPF.TryCleanupAndDispose(_getValueGroupHeader.DataContext);
_getValueGroupHeader.DataContext = null;
}
_materializedGroupHeaders[itemIndex] = headerWrapper;
return(headerWrapper);
}
