We are working on implementing exporting to Excel in our application's radgridview - we used this tutorial: https://docs.telerik.com/devtools/wpf/controls/radgridview/export/generic/export and it works with some errors. 

When trying to create a file with an .xls file extension, we get an error of "The format and extension of this file do not match". How do we fix this? 

When saving, the file extension appears twice after the "Excel files" in the save dialog. Why is this? Is this potentially causing issues? 

Also, we would like to change the formatting of the file on export - for example, freezing the headers, automatically setting the column widths, etc - what is the best way to set these properties?

dear sir,

 We use RadDocking inside our project.

unfortunately when we remove RadPane from the RadPaneGroup we still see it in visual tree as hidden= true. we want it to be removed  and not saved when we calls SaveLayout.

to avoid this behavior we use :RadPane.RemoveFromParent , but after calling the function we get this exception:

Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Controls.RadDocking.HidePane(RadPane pane)
   at Telerik.Windows.Controls.RadPane.Close()
   at Telerik.Windows.Controls.RadPane.OnIsHiddenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.Docking.PaneGroupBase.ExecuteCommand(RadPane pane, ICommand command, PaneGroupBase groupBase)
   at Telerik.Windows.Controls.Docking.PaneGroupBase.<>c__DisplayClass3.<OnPaneCommandInvoke>b__2()
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at System.Windows.Application.Run(Window window)
   at System.Windows.Application.Run()

please we must find a solution .

Thanks you

Yafit

Hi,

I have a project where I need to be able to drag a ListBox Item to a different ListBox. If I dont populate the second Listbox with anything; then when I drop the item, it just disappears. When I have at least 1 Item in the second ListBox then I get "'Element already has a logical parent. It must be detached from the old parent before it is attached to a new one". I need to be able to do this as well as add a prefix to each added item eg: "A - FirstItem" and "B - SecondItem".

I tried using the Converter class too but it doesnt seem to work. It is important to note that I have tried this method using Binding as well as just dynamically adding objects to the Listbox. Nothing works. Attached is all the images from my sample project needed to diagnose my issue.

Please Help

Thank you,

Dean.

Hi

I'm trying to style the column header background colour of the RadTaskBoard.

Using the RadTaskBoard.ColumnHeaderTemplate you can change the content of the column header as in the image below, but you can't style the background.

I need each column header (and collapsed header) to have its own colour. Is there a way I can achieve this?

Thanks

Guy

Hello.

Hello.

I posted a post a while ago and had the desired solution.

https://www.telerik.com/forums/error-empty-gridview-message-content-in-gridview-sdk

However, in this case, there was only one grid view in the tab control and the other items were of different types.

Now I need multiple gridviews inside the tab control.

If you add multiple gridviews, an error like the link above will occur.

The first gridview passes, but errors start in the remaining 2nd and 3rd gridviews.

The attached example is just adding TabItems from the previous link and deferring InsertAdditionalContentControl .

How to solve this?

Thanks.

GanttView can import from xml , but export xml need to install MSProject.

Can I export the GanttView to XML format do't install MSProject ?

I am trying to achieve the following behavior:

1. Wheel will control vertical scroll

2. Horizontal scroll will be visible with resize controls (zoom in and zoom out)

Is this possible?

The RadToggleButton is in example.xaml, how to get the statue of it(ischeck or not) in ViewModel.cs ?

And change the statue of Button in ViewModel.cs?

Thanks~

Hi, Telerik,

I am developing for WPF Prism application on .Net 5.

I need to provide an editor functionality which is in MS Word.

I found Perlom's question here and have read it but, I can't have any clue.

How can I solve this problem?

For your information, I am going to attach an image file captured  Perlom's question.

TIA

Kang