Hello,
I wrote a SL application that loads huge data from WCF and display it in a gridview... keeping things simple I've got a main menu with 3 items (0 parameters,1 parameters, 2 parameters) and it shows up some data based on some criteria... On the click of a menu item I do a

gvContent.Items.Clear()

but if the user has just loaded the data from another menu item's content, IE/FFox won't free the ~150MB of ram allocated for the gridview.... need I to implement an IDisposable inside the gvContent's usercontrol? how I remove the items of the Gridview?

Thanks in advance

p.s. another question.... when I detach an event doing:


what happens to the 2 EventHandler created? when are they disposed ??(I've always asked myself)
Thanks
Paolo

Hello Paolo,

Regarding your first question . In general you will not need to do anything additional in order to free memory ( such as implementing IDisposable) . As usually the framework will keep an object in memory as long as there is a reference to it.

So the next question would be - does RadGridView keep reference to the previous items or something else prevents the GC to flush the memory.

This can easily be checked - e.g.  try a regular  List box instead of  the RadGridView . If the problem disappears this would mean that RadGridView is to blame for the memory leak.
In such case please let us know and we will address this immediately.

Regarding your second question :

Event handler is delegate  - in other words just something that points to  another object's method.

The important thing which happens when you use " -=" to detach an event handler is that you break the reference between the two objects - the one raising the event and the one listening for the event.

Finally when an object remains unreferenced by other objects  it can get  collected by the GC.

Anyway, again if you  suspect any memory-related problems in your application are caused
by RadGridView or other controls from our suite - please let us know. ( with some details how to reproduce if possible ) .   Such issues are always addressed with high priority.

Regards,
Pavel Pavlov
the Telerik team

Hello Pavel,
I've checked.... I got the same problem with the ListBox... it's really strange...when I load the UC dinamically it tooks 4mb (not loading any telerik component) then cleaning everything I free 500kb...

Hello Pavel,
sorry to disturb  you again... I thinks I've found something usefull.. I've found a post about finding memory leak by a colleage of yours... I've used windbg and after having done the switch between the usecontrol and cleared it I figured this :

I've done a !dumpheap -stat -Type Telerik and omitting the small ones... I got

0ac18cb4        7          336 System.Collections.Generic.Dictionary`2[[System.String, mscorlib],[Telerik.Windows.Controls.Animation.RadAnimation, Telerik.Windows.Controls]]
0ba51a38        1          344 Telerik.Windows.Controls.RadGridView
0ac15a90       22          352 Telerik.Windows.ClassHandlersStore
0ac15694       23          368 Telerik.Windows.RoutedEventHandlerInfoList
0b53d08c        3          420 Telerik.Windows.RouteItem[]
0ac19920        7          420 System.Collections.Generic.Dictionary`2+Entry[[System.String, mscorlib],[Telerik.Windows.Controls.Animation.RadAnimation, Telerik.Windows.Controls]][]
0ac1745c       20          480 System.Collections.Generic.List`1[[Telerik.Windows.RoutedEventHandlerInfo, Telerik.Windows.Controls]]
0ac12690        4          496 Telerik.Windows.Controls.RadMenuItem
0ac1d4dc        1          604 System.Collections.Generic.Dictionary`2+Entry[[Telerik.Windows.DependencyObjectType, Telerik.Windows.Controls],[System.Object, mscorlib]][]
0ac187dc        1          604 System.Collections.Generic.Dictionary`2+Entry[[System.Windows.DependencyProperty, System.Windows],[Telerik.Windows.CoerceValueCallback, Telerik.Windows.Controls]][]
0ac1a238       41          656 Telerik.Windows.Controls.Office_BlackTheme
0ac13fc8       29          696 System.Collections.Generic.List`1[[Telerik.Windows.RoutedEvent, Telerik.Windows.Controls]]
0ac15f44       69          828 Telerik.Windows.DependencyPropertyKey
0ac153f4       34         1088 Telerik.Windows.CoerceValueCallback
0ac13b54       56         1120 Telerik.Windows.DependencyObjectType
0ac15c60       44         1352 Telerik.Windows.RoutedEventHandlerInfo[]
0ac14a5c        1         1436 System.Collections.Generic.Dictionary`2+Entry[[System.Type, mscorlib],[Telerik.Windows.DependencyObjectType, Telerik.Windows.Controls]][]
0ac15828       22         1812 Telerik.Windows.ClassHandlers[]
0ac132e8      115         3220 Telerik.Windows.RoutedEvent
0ac1559c      530        10600 Telerik.Windows.PropertyMetadata+<>c__DisplayClass1

I've done a !dumpheap -MT 0ac1559c     
and got :


doing a !gcroot


As far as I've seen this can a memory leak.... can you confirm? Consider that I've not loaded any item from the GridView, just loaded it and then done a clear...

My XAML file is :


Hope this helps... Thanks

Hi Paolo,

Thanks for taking the time and profiling our memory usage. What you have found out are static references to dependency property metadata objects that RadGridView is using. This is definitely not a memory leak, because this is the way Silverlight works, it requires you to create static fields in order to have dependency properties.

All the best,
Stefan Dobrev
the Telerik team