Hello,
somtimes get the following NullReferenceException in RadDropDownButtons:
1.
Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
2.
StackTrace:
3.
bei Telerik.Windows.Controls.RadDropDownButton.<>c__DisplayClass2.<OnLoaded>b__0()
We were puzzled and surprised, because we did not change anything and we have no idea why this occurs. the stacktrace is also very short and does not show from where it comes.
Looking at the Sourcecode we probably found the bug. There is a Dispatcher call without checking in the dispatcher call for NULL.
namespace
Telerik.Windows.Controls
{
[TelerikToolboxCategory(
"Navigation"
)]
public
class
RadDropDownButton : RadButton, IPopupHost, IPopupWrapperOwner, IDisposable
{
private
void
OnLoaded(
object
sender, RoutedEventArgs e)
{
this
.isLoaded =
true
;
RadDropDownButton isOpen = sender
as
RadDropDownButton;
if
(isOpen !=
null
&& isOpen.popupWrapper !=
null
)
{
base
.Dispatcher.BeginInvoke(() => isOpen.popupWrapper.IsOpen =
this
.IsOpen);
}
}
}
}
Please fix it like this:
namespace
Telerik.Windows.Controls
{
[TelerikToolboxCategory(
"Navigation"
)]
public
class
RadDropDownButton : RadButton, IPopupHost, IPopupWrapperOwner, IDisposable
{
private
void
OnLoaded(
object
sender, RoutedEventArgs e)
{
this
.isLoaded =
true
;
RadDropDownButton isOpen = sender
as
RadDropDownButton;
if
(isOpen !=
null
&& isOpen.popupWrapper !=
null
)
{
base
.Dispatcher.BeginInvoke(
() => {
if
(isOpen.popupWrapper !=
null
{
isOpen.popupWrapper.IsOpen =
this
.IsOpen;
}
});
}
}
}
}