We have used C1DateEdit control(Component one Control) in WPF application and it has some issue with it.
Please find below the scenario and the issue.

Scenario 1:
Step 1 : Create a WPF-Windows application and add Window1.xaml .
Step 2 : Add C1DateEdit control in WindowsFormsHost element.
Step 3 : Execute the application.
Step 4 : Click on the dropdown of the DateEditControl. It throws the below exception.


Scenario2:
Step 1 : Create a WPF-Windows application and add Window1.xaml .
Step2: Create a usercontrol(ucDateTimePicker.cs) by adding C1DateEdit control in a panel and set panel to fill the usercontrol.
Step3: Add the user control in WindowsFormsHost element of Window1.xaml.
Step 4 : Execute the application.
Step 5 : Click on the dropdown of the DateEditControl. It throws the below exception.

Expected Result:
When click on the dropdown of the DateEditControl, it should drop the calendar.

Exception:
System.NullReferenceException: Object reference not set to an instance of an object.
at C1.Win.C1Input.C1DropDownControl.OpenDropDown()
at C1.Win.C1Input.C1DropDownControl.a()
at C1.Win.C1Input.C1DropDownControl.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Note: The same scenario works well with Windows application of visual studio 2005.

Thanks
Raje