using linq to xml in silverlight? - c#

I did implement a web application(asp.net,c#) where it has couple of pages .Each page has the ability to read the values from an xml file and passes into couple of text boxes in each page.User has the ability to edit the values and save,which inturn saves the xml file.I did use the linq to xml .
I have to move to the silverlight now.so i am trying to implement the same logic in a new silverlight project.I m trying to use the linq to xml in silverlight also.But some how i am unable to read the xml file which is not in the xap file.Here is my code
XDocument doc = Document.Load("C:\Data\Data.exe.config");
var applicationSettings = (from x in doc.Descendants("applicationSettings")
from kvpair in .Element("Data.Properties.Settings").Elements("setting")
select new
{
Name = kvpair.Attribute("name").Value,
Node = kvpair.Element("value")
}).ToDictionary(x => x.Name, y => y);
string Account = applicationSettings["Account no"].Node.Value.ToString();
txtAccountno.Text = AttendanceWindow;
string Details=applicationSettings["Details"].Node.Value.ToString();
txtDetails.Text = Details;

I am assuming that "C:\Data\Data.exe.config" is a file that sits on the server? Keep in mind that Silverlight is executing on the client-side. Not only would you have to give Silverlight permission to access that directory (see this link for some details), but you'd be accessing the client's hard disk, not the server's. In order to get that file's contents, you'd be better off parsing the XML server-side and sending whatever settings you require from it to Silverlight via web services.
If the file really does sit on the client's computer, then you need to create an out-of-browser Silverlight project: http://msdn.microsoft.com/en-us/library/ee721082(VS.95).aspx
EDIT:
Ah, I think I see what's going on now. The Document.Load method by default assumes the URI points to a resource within the XAP: http://msdn.microsoft.com/en-us/library/bb538371(v=vs.95).aspx
What you'll probably need to do is described in this MSDN article, which will use a stream approach to loading the XML: http://msdn.microsoft.com/en-us/library/cc645034(v=vs.95).aspx#Y0

Your problem is related to which areas on the disk you are allowed to access.
You need ensure that Silverlight can access the file, that it has rights to the files location, and that silverlight is configured to be able to access local files. Either the file must be moved to local storage or you must run with elevated privilages out of the browser.
See also: http://www.codeproject.com/KB/silverlight/FileExplorerInSilverlight.aspx for an example of accessing files from Silverlight

In Silverlight 5 it is possible to run the Silverlight application in-browser with elevated permissions, enabling you to access the entire file system. Otherwise you are restricted to the isolated storage area.

Related

Permanently add a database to an application C#

I'm trying to create software that will add a computer to an Active Directory domain. One criteria I need to meet is the machine must be added to the proper OU. In order to do this I have a set list of site locations with addresses (this is how we determine OU). This list is currently in the form of an ACCDB file, and I want to include this within the application as the Access list will not be changed.
Everything I see wants the DB file to be connected to in a different location such as server or on the local machine. My preference is to use the DB file as a reference or something inside the program's .exe file itself. I may be missing something horribly obvious, but it's been messing with me for a couple days so I'm reaching out for help.
To clarify, this software MUST be self contained (no installer). It must also be able to determine the proper OU to join to the domain (no access to shares until the PC joins the domain). It must also be user-friendly enough to avoid mistakes, meaning I want to avoid copying distributing multiple files that must go to a correct location. This is why I want to embed the ACCDB file into the application for on the fly use.
Things get much easier because this is static data. You don't have to worry about persisting this data, reclaiming changes into your program, or users accidentally deleting something, etc. You will be able to just use an embedded resource in your application. In the link, follow the examples using the image file. Text file examples will corrupt your database.
However, there is still a trick to doing this. The problem is the Access engine included with Windows will not be able to open the database as a resource, and so you will need to save this file to the local hard drive. The good news is its not as bad as it seems, because your program can do this as needed, and make sure it's right, rather than asking the user to put a file in a specific place.
As for where to put the file when you extract it... the safest and best place is the Application Data folder. You can easily get the path for this folder by checking the results of this call:
Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
This will give you a path where standard privilege users do have write access, no matter which user.
In summary:
Embed the ACCDB as a resource.
When your program runs, get the Application Data path using the Environment object.
Open a FileStream for writing to a file based on the path from #2
Open the embedded resource as a Stream object in C#
Copy the stream from #4 to the stream from #3. Make sure to use a mechanism intended for binary data, rather than text.
Close/Dispose your streams, so no locks remain on the file. This is as simple as putting using blocks in the right places.
Open a normal Access connection to the file you just made, using any of the thousands of tutorials or examples available on the web as a guide.
In this way, you only need to distribute the final .exe file, and users won't need any special permissions to use the database. You don't have to worry if a user deletes your file; it's still embedded in the application, which will recreate it if needed every time it starts up.
The downside is a clever user may be able to manipulate the database to end up in an undesirable OU. If you need to worry about this, you should consider having the program check a web service, rather than using embedded data. Anything you embed can ultimately be altered by an end user. A web service is also nice because you can update your mapping data as your organization evolves, without needing to rebuild or redistribute the program.

Anybody can help to reach exact path [duplicate]

I have the code to save a file in a folder in directory
string timestamp = DateTime.Now.ToString("MM-dd-yyyy.HH-mm-ss");
var file = File.Create("Owe-Data.txt" + timestamp);
var com = System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase + timestamp + #"\Data" + file;
MessageBox.Show(com);
if (!Directory.Exists(com))
{
Directory.CreateDirectory(com);
}
using (var sw = new StreamWriter(com))
{
sw.WriteLine(InputData);
}
}
i Displayed COM it gives path bt i cant see the Data folder or Owe-Data file at that path
Anybody can tell why this happening, or should i save the Data folder in current directory where this prgram running? bt i dnt know how to reach that path. Any solutions ??
Working on windows phone 5, visual studio 2008 .NET framwork 2.0
As per the Exceptions section of documentation,the above exception is thrown when
ArgumentException ------- folder is not a member of System.Environment.SpecialFolder.
It means the OS where you are running this command does not have Environment.SpecialFolder.CommonApplicationData as one of the special folder.
For knowledge,
Environment.SpecialFolder.ApplicationData is the most common one. This folder holds per-user, non-temporary application-specific data, other than user documents. A common example would be a settings or configuration file.
Environment.SpecialFolder.CommonApplicationData is similar, but shared across users. You could use this to store document templates, for instance.
Environment.SpecialFolder.LocalApplicationData is a non-roaming alternative for ApplicationData. As such, you'd never store important data there. However, because it's non-roaming it is a good location for temporary files, caches, etcetera. It's typically on a local disk.
I think the problem may be that Environment.SpecialFolder.CommonApplicationData is common and shared between different users and the user with which you have logged in is not having rights to access the folder or the Visual Studio has not been started in Admin mode.
EDIT Look at link and try to add a manual registry Common AppData defined in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders\
Given you are asking about a .NET Windows Phone application as per the tags
I think your problem is that a .NET Windows Phone application does not have direct access to the file system; it can only access IsolatedStorage this is by design.
I would quote a Microsoft source for this but I can't seem to find one!
EDIT
See this article from MSDN

Writing a Dynamically built HTML to a file in ASP.NET 4.0

I have a web form which takes in user information. The value of various text boxes is used to build a html file. I write this html to a file( with specific name) and then prompt user to Save this file.This html is used for creating outlook email signatures. Currently I have this html within the application.This has been deployed to the server. I had to set write permission on this file for all users for it to work.
Are there any security risks? What happens if multiple users access this applications and write to the file at the same time.
When you say the file has "a specific name", do you mean that it is always the same name? If so, then yes, there will be problems if multiple users use this functionality at the same time. They'll be overwriting the one file and downloading each other's data. You would need to generate a unique filename each time the process runs to avoid this.
But do you actually need to save the file?
Or is your goal purely to produce some HTML for the user to download, and the way you are doing this is by writing it to a file, and then prompting them to download that file?
If you don't need to save the file, but rather just need to generate HTML and prompt the user to save, just serve it up as a normal page, and set response headers such that their browser will download it. Something along these lines:
Response.AddHeader("content-disposition", "attachment;filename=my_file.html");
From what I understand, the user fills the web form and submits. Immediately, an html file pops up for download from the server. I think this is very neat implementation of this scenario. You just need to make sure that resources are released properly in order to prevent locking of files.
When multiple users access this application, it should not break since separate files are created with a specific name (as you have mentioned). I don't know what logic has been used to create unique names. At some peculiar situation (this is purely dependent on your name calculation logic) if the calculated specific file name somehow becomes similar to an existing file, you should have code in place to replace or create a different version of the same file name. Locking could occur if you are writing captured data from web form into the same file again and again without disposing your stream/File objects . Make sure you dispose your objects after use in the code.
It would be great if you give access to the application pool of the web application to a user who has write access to that file/folder instead of giving everyone the write access. In this way, your application gets full rights to perform write operations rather than users having rights. If users have write access on the file/folder, it is very easy for anyone to peek in and do something unexpected.
Hope this helps.

Reading local MDB(Access) database using silverlight 5?

I am tring to find someway to read from local MDB file. It is a requirement that user may have their own access database. And my silverlight app would be interacting and performing calculations on that data.
Is there any way I can work with it? I have found that ADO.net doesn't come with Silverlight 5.
All the examples I have seen so far, are assuming that there is Wcf service between silverlight client and database.
I can see two options for you:
1) Using the open file dialog get the user to select the file so you can copy it to the Isolated Storage then work on it and get the user to save the file to disk once you have done.
2) Get the user to install you Silverlight application out of brower, this will give you access to the file system and freedom to read the MDB. http://msdn.microsoft.com/en-us/library/dd550721(VS.96).aspx#special_features_for_outofbrowser_applications
Personally i prefer the second option.
I'm assuming you are using ADO.Net to read the database, so you'll need to ensure that the correct provided is installed.
good luck

Where to store configuration for a simple .NET application?

I'm programming a fairly simple application which I want to cut to just one simple EXE file + some data storage (XML for example).
My question is regarding configuration files. Where to put those files? I saw a few applications that have just an EXE file (uTorrent, Media Player Classic - I can use them without any installation), but they store their config somewhere else. How to achieve this?
How would you approach such situation? Is it better to try to achieve the thing I described above, or simply use a configuration file and data storage in the same directory as the EXE file?
Creating or using a file in the same folder (or in the App_Data) is pretty standard practice.
You use an installer like Inno Setup (free) to create a single exe installer (http://www.jrsoftware.org/isinfo.php)
If you want a DB rather than XML, have a look at SQLite (http://www.sqlite.org/) a file based DB or use an MS Access DB.
I think you want to take a look at Application Settings. This is an API which allows you to save user or application settings using a strongly typed API. Under the hood the settings are stored via XML serialization.
This API works with virtually every type of .Net application including low permission Click Once versions. It does the work of finding the place on disk appropriate for storing the data and completely hides it from you. It also has a nice GUI integration into Visual Studio.
EXE-only programs store their data either in the Windows Registry or in the user's Application Data/AppData folder. Although this may appear cleaner at first, it just hides the ugliness of scattering all your data around. I would suggest just going with a simple XML/INI/text data file that is generated when needed and easy to migrate.
Please see: WPF/C#: Where should I be saving user preferences files?
You could use the app.config file for storing your configuration. For the data, I would sugest something like db4o or SQLite.
Edit
This tutorial can show you how simple is to use db40 to store and retrieve your data.
Do not forget Isolated Storage. It gives you a place to read and write files to without the need for you to specify a location. Sometimes it is the only way sandboxed applications (like Silverlight) can store user or machine specific data locally. See here for an example.
I would store them in the same directory. That just seems easier to me, at least that's the way I always do it.

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