I'm trying to launch a SL4 OOB application from the web browser. I'm currently trying to achieve this by associating a file type with sllauncher.exe and then adding the SL4 OOB application id as a parameter. The SL4 OOB application is launched when the specific file type is downloaded from the browser, but in order for me to create an installer I need to be able to retrieve the application id so I can update the registry entry for the file type association.Does anyone know how the application id is generated or if it's possible to force a specific application id to be used?
I fear that this won't be easy...
There's a method Deployment.GetAppIdForUri which sounds like it does exactly what you need, but unfortunately it is marked SecurityCritical so you can't use it.
A hack that might work is this:
When the app is installed OOB, you might use Application.Current.Host.Source or something like that plus a bit of substring magic to get the app ID. Unfortunately, I'm not able to test that right now because I'm uninstalling the VS2010 RC on this machine right now ;-)
Anyway, if that works, you might take the ID and write it into IsoStore for later use.
Forcing a specific ID for the app would be nice, but I think it's not possible.
Cheers, Alex
The shortcut file of Silverlight OOB application includes the application id. Retrieving the application id from the shortcut file is work to me.
Related
I have a software requirement like that:
An app run on window but this app can connect to server to get and use its file by user.
User A can Log in, View all his file from server, Create new file, Edit content, Upload, Share file, View share file of another user.
I usually use .Net framework.
So what technology should i used to resolve this requirement
I really need some advice helpful
Thank!!!
Based upon the comments, I would advice to go for a clean separation between your UI and application functionality.
This will allow you to build possible multiple interfaces ( Win8, Mobile, ... ) for the same application. For Windows environment and you are used to .NET I suggest you take a look at WPF ( Windows Presentation Foundation ). I'm sure you will find that some people already created pretty solid file managers in WPF. It could serve as a good base for yours.
Few pointers if you look at WPF, look on http://www.codeplex.com for frameworks that could ease your coding. (Caliburn.Micro, PRISM, ... ). A very popular pattern is MVVM, this will structure your code so you can easy adjust it in the future.
Further more I think you can get very far with the windows build in libraries to manage the files.
For the editing you'll find a nice challenge to do that in the application, the easy road would just be to let the user open the file from the application into it's proper environment ( e.g.: a word document in Word, excel document in excel, etc.. ).
To get sharing going, multiple options are available. I'm think of sending email links, in application notifications, etc... Sharing could also mean that you set certain permissions on those files. For this you could take it to the limit of domain security management ( talking to an active directory to get the proper permissions etc. ) or you could simple implement your own into your application and restricting it on that level.
So I have a local WPF web browser application and I need it to write to a text file. However I always get the an exception of type System.Reflection.TargetInvocationException. I don't get any more information but I'm pretty sure it is because it is being run from a web browser (security etc.).
The code I am using works in a regular windows form application etc. it is the usual:
StreamWriter sw;
sw = File.CreateText("c:\\myTextFile.txt");
sw.WriteLine("First line");
sw.Close();
So, is there a workaround for this?
Many thanks,
Thomas
You could try running in Full Trust mode.
WPF in a browser is going to default to partial trust. You can change that in the Security tab in Project Properties (subject, of course, to it being installed by a trusted user).
The issue is not WPF security problems. The issue is an operating system security feature in play: you can't write to the root of the C: drive without admin privs. Not only would your app need to be in WPF Full Trust mode, but you'd need to grant your app administrative priveledges on Vista and Windows 7 and beyond.
All that said, you should be able to write to files in non-protected paths. For example, you could write to a temporary file as returned by Path.GetTempFilePath(). However, it's likely your WPF browser app will still have to be running in full trust to write to disk at all.
See this page, describing Partial Trust security considerations. If you need to store the file for your own application's use, consider using Isolated Storage. If you want to allow the user to save a file to disk, you can use SaveFileDialog.OpenFile to allow the user to choose a path and confirm saving the file.
In this thread from a year ago it's explained that WriteableBitmap will block read access when any part of it comes from an outside domain - say a free image server.
It's further elaborated upon that this is for "DRM". I guess there's some big threat of someone writing a movie-ripper in Silverlight that includes a movie from another domain and then re-captures it... except for the realization you can just rewrite the bloody xap as it comes down the wire and then it's same-domain! But that's neither here nor there.
Anyway, obviously I'm trying to use WritableBitmap to export a screenshot of the user's current setup; but I'm stopped by this cross-domain issue.
Is there really no supported way to do this in the latest version of Silverlight? No crossdomain.xml or clientaccesspolicy.xml? Isn't this crippling for Silverlight - a giant "Screw You", putting half-hearted security roadblocks in that impede developers but don't stop attackers?
Edit: This question is identical to this question here.
Your sentiment is shared by many, many devs trying to do this for legit purposes. There are some work-arounds out there, all of them either hacky or bizarro. But this is probably the best one I've seen: Screen Capture in SIlverlight 4.0.
Just read again and saw that you're not looking for a crossdomain.xml solution. This page has some other options (again, no solution out there is "great"): http://betaforums.silverlight.net/forums/t/118030.aspx
Also, not sure if this is an option, but your app as an OOB app will not be restricted to security checks in ClientAccessPolicy.xml or CrossDomain.xml. Is Out-of-Browser an option for you?
EDIT:
Upon further review of the post and comments, I believe (Tom, please confirm this) that the need isn't to get a screenshot of the user's instance of the SL app running on their own box (which something like Customer Support in Silverlight would take care of pretty well).
Rather, it is to take picture of the user's screen (same as PrtSc-ish). In this case, it is a lot tougher, but not impossible. Rui show's how he does it here, but it relies on a component already being on a user's machine. Jeremy get's even more creative with Silverlight 4 Hack: Use Native/Desktop CLR Without COM Registration, which would effectively allow access.
This WritableBitmap behavior have nothing to do with DRM and everything to do with security. If the screenshot you trying to take shows image element with content from different domain then that domain must have crossdomain.xml file with appropriate permissions. You can contact domain owner and ask them to place crossromain.xml in the root of their domain.
Alternatively, Full-Trust OOB application should do the trick since it doesn't check for crossdomain.xml.
Ok, If you have <Image Source="http://crossdomain.com/someimage.jpg" /> in your visual tree and you try to create WriteableBitmap from it, that WriteableBitmap's pixel access will be locked, crossdomain.xml or not. (Shame on you microsoft). Good news (sorta) is, you can use following workaround: Load image using WebClient; call SetSource on image with stream from OpenReadCompleted handler. Create your WriteableBitmap and notice how Pixels property doesn't throw security exception anymore. Far from ideal, but manageable.
As explained in the identical question the only way to get silverlight to allow you to get the content out of a Writeable Bitmap without any of the following:
Out-of-browser
Service/Code/App/Rooted GAC otherwise installed on the user's Machine
Elevated Trust
is to proxy the content and trick silverlight into thinking it's all from the same domain.
I have been tasked with writing an installer with a silverlight out of browser application. I need to.
get the version off a local EXE
check a web service to see that it is the most recent version
download a zip if not
unpack the zip
overwrite the old EXE
start the EXE
This installer app is written in .NET WinForms now but the .NET framework is an obstacle for people to download.
The recommended solution is to use a SLOOB however i am not sure how to assign full trust. If i assign full trust can I start a process.
Thanks
Looking into this, I suspect you're going to have to create the process using WMI through the COM interface. At the end of the day, that makes this a very difficult option and very subject to failure due to a host of reasons (WMI being disabled or secured, user won't give full trust, etc.) I suspect you would be much better off creating a .msi deployment package or something similar that was able to go out and download the framework, if necessary. There are a lot of deployment models available, almost all of which feel superior to this one.
That said, if you're going to do this:
To get the COM object, you're going to want to use the AutomationFactory.CreateObject(...) API. Tim Heuer provides a sample here.
To actually do the WMI scripting, you're going to want to create the WbemScripting.SWbemLocator object as the root. From there, use the ConnectServer method to get a wmi service on the named machine. You can then interrogate the Win32_Process module to create new processes.
Edit: I spent a little time working on this and, even on my local machine as Admin I'm running into security problems. The correct code would be something similar to:
dynamic locatorService = AutomationFactory.CreateObject("WbemScripting.SWbemLocator");
dynamic wmiService = locatorService.ConnectServer("winmgmts:{impersonationLevel=impersonate,authentationLevel=Pkt}//./root/cimv2");
dynamic process = wmiService.Get("Win32_Process");
dynamic createParameters = process.Methods_["Create"].InParameters.SpawnInstance_;
createParameters.CommandLine = "cmd.exe";
wmiService.ExecMethod("Win32_Process", "Create", createParameters);
Silverlight 4 will have support for something like this: http://timheuer.com/blog/archive/2010/03/15/whats-new-in-silverlight-4-rc-mix10.aspx#sllauncher
I'm not finding much documentation on how to use Windows Authentication in a WPF app. I wouldn't have thought that it would be any different than in any non-WPF app, but it seems that it is. I want to go into my project Properties -> Application and ensure that Windows Authentication is on, but that option is not available in a WPF app (as the following document confirms).
http://msdn.microsoft.com/en-us/library/tzdks800.aspx
If I ignore all that and just look at My.User.Name (VB), it is empty. This tells me that somehow Windows Authentication is not enabled.
Seems like there is a concept I am missing; could someone point me in the right direction?
My plan is to use PrincipalPermissionAttribute to restrict access to certain parts of my app (or perhaps the entire app, by applying it to Application_Startup()).
Itowlson's answer is correct, but also, in order to use the PrincipalPermissionAttribute on any method, you have to first make the windows principal the current principal by calling:
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal)
The reason this doesn't work in WPF is that these services are implemented in VB's WindowsFormsApplicationBase class, which isn't used in WPF applications. To do the same thing yourself:
Call WindowsIdentity.GetCurrent() to get the Windows user identity. You can get the name from this.
If you specifically want to set the thread principal the way the VB Windows Authentication option does, call Thread.CurrentPrincipal = new WindowsPrincipal(WindowsIdentity.GetCurrent()) -- this is exactly what WindowsFormsApplicationBase does internally.
EDIT: If you prefer the My.User API, it looks like you should be able to do the same thing by calling My.User.InitializeWithWindowsUser(). I haven't tested this though.