"Download Dialog" from an XBAP

Question

According to these: http://msdn2.microsoft.com/en-us/library/aa480229.aspx and http://msdn2.microsoft.com/en-us/library/aa970910.aspx I can fire off a "Browser Download Dialog" from within an xbap, which I assume would enable me to give a file to the client.

How exactly is this done?  I've searched for hours now and can find no example.  I've tried using a frame control but it fails with "Failed to convert resource into object."  Will I need to write some something to force a download from an html page embedded in a frame?

I've found a vague tip here http://scorbs.com/2006/06/14/photostore-xbap-standalone to set the Content-Disposition header to “attachment” on the server.  But that tells me nothing about what I need to do in my code.

FYI, I'm wanting to use this for save fuctionality of my vector drawing program at http://designer.cooltext.com

Bryan

Answer 1

I really need an answer for this.  Does anyone have a clue or can at least point me in the right direction?

Answer 2

I don't believe SaveFileDialog was implemented to work in Partial Trust in .NET 3.0.

Answer 3

Ashish Shetty - MSFT wrote:

I don't believe SaveFileDialog was implemented to work in Partial Trust in .NET 3.0.

That's completley correct.  SaveFileDialog is disabled.  But, the sandbox docs I linked to still state that the IE Download Dialog is enabled under the "web integration" section, so I should be able to force the browser to download a file somehow.

Answer 4

See this article: http://support.microsoft.com/kb/260519. From within an XBAP, navigate to a URL that the server will return with "Content-disposition: attachment".* That URL has to come from the site-of-origin of the XBAP, as a security restriction. Then the browser will prompt the user to Open or Save the file, and the XBAP will continue to run if they save.

* In IIS, the setting is very easy: Open the virtual folder containing your file, get its properties, and add the header in the HTTP Headers section.

Answer 5

I'm running the following:

HiddenFrame.Navigate(new Uri("http://designer.cooltext.com/Setup.zip"));

I've setup the header and verified that it's being sent via Fiddler.

And am still getting the following exception.  How exactly am I suppose to navigate to this url?

Startup URI: http://designer.cooltext.com/LogoDesignerXbap.Xbap
Application Identity:

System.InvalidOperationException: Failed to convert resource into object.
   at System.Windows.Navigation.NavigationService.GetObjectFromResponse(WebRequest request, WebResponse response, Uri destinationUri, Object navState)
   at System.Windows.Navigation.NavigationService.HandleWebResponse(IAsyncResult ar)
   at System.Windows.Navigation.NavigationService.<>c__DisplayClassc.<HandleWebResponseOnRightDispatcher>b__8(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext 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, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   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.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.StartDispatcherInBrowser(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext 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, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

Answer 6

I've also tried:

((NavigationWindow)MainApplication.Current.MainWindow).Navigate(new Uri("http://designer.cooltext.com/Setup.zip"));

 

And got:

Startup URI: http://designer.cooltext.com/LogoDesignerXbap.Xbap
Application Identity:

System.Security.SecurityException: Request for the permission of type 'System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
   at System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet)
   at System.Security.CodeAccessPermission.Demand()
   at MS.Internal.PresentationFramework.SecurityHelper.DemandUnmanagedCode()
   at System.Windows.Navigation.NavigationService.DelegateToBrowser(Boolean isPack, Uri destinationUri)
   at System.Windows.Navigation.NavigationService.GetObjectFromResponse(WebRequest request, WebResponse response, Uri destinationUri, Object navState)
   at System.Windows.Navigation.NavigationService.HandleWebResponse(IAsyncResult ar)
   at System.Windows.Navigation.NavigationService.<>c__DisplayClassc.<HandleWebResponseOnRightDispatcher>b__8(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext 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, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   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.Threading.Dispatcher.Run()
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.StartDispatcherInBrowser(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
   at System.Threading.ExecutionContext.runTryCode(Object userData)
   at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext 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, Boolean isSingleParameter)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Boolean isSingleParameter, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.InvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Boolean isSingleParameter)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)

The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.Permissions.SecurityPermission
The first permission that failed was:
<IPermission class="System.Security.Permissions.SecurityPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
version="1"
Flags="UnmanagedCode"/>

Answer 7

More security to embrace: 

1. Only a top-level navigation (within the root NavigationWindow) can be delegated to the browser.
2. Only a user-initiated navigation can be delegated. (Considering your scenario, partial-trust code shouldn't be able to open the browser's print/save dialogs. Also, in general, we don't allow an XBAP to close itself, which navigating away does.) So, use a Hyperlink and let users click it. Of course, you can style it any way you want; it doesn't have to look like a hyperlink at all.

Good luck.

Answer 8

Thanks.  Finally got it.

<TextBlock><Hyperlink NavigateUri="http://designer.cooltext.com/Setup.zip" RequestNavigate="saveToWebService">Lame Xbap Save</Hyperlink></TextBlock>

In saveToWebService I get to call a web service and upload the file to my site, which will then get immediatly downloaded.  It's an obsene waste of bandwidth but lays the groundwork for a web workspace like they have in google docs.

 

Answer 9

I'm having a similar problem, only instead of downloading a file from the server I'm trying to upload a file from the client machine to the server from inside an xbap.  I'm getting the "Failed to convert resource into object."  exception you mentioned earlier.  Unfortunetly I'm not clear how you resolved the problem.    Thanks for any help you can provide.

 

-rfuller