Save User Data to Local Application Storage in Windows Store App Using C#

Gaurav Gupta

12 Comments

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Mario Mendoca8y ago
It would be more helpfull if you had all the code here. For example what kind of return does the SaveAssync has?
Gowtham Rajamanickam10y ago
good article..
Sean12y ago
It would be helpful if all the assembly references needed were listed. I've reduced my errors with this code significantly by adding the following:using System.IO; using Windows.Storage; using System.Threading.Tasks; using Windows.Storage.Streams; using System.Runtime.Serialization;
Giancarlo Marin13y ago
:) good!
surya syamala13y ago
can u pls tell me where the whole code can be downloaded
naren dran13y ago
Please update your article, praveen vr is right!
berhan cem13y ago
Hey thx for the code but I'm trying to compile project like an hour but it doesn't work :( There are some missing arguments like UserProfileId what is that and why it doesn't work? So if you could just upload your full project here and we can analyze that it would be great..
tak v14y ago
I created a public async void SaveAsync() and put it right after public MainPage(), but I get an error: 'savinguserdataonsuspended.MainPage.SaveAsync()' does not return a Task and cannot be awaited. Consider changing it to return Task. Also it says that UserName and UserProfileId do not exist in current context but I guess they have to be created on the next page. Could you please post a fully working project solution, like you have on your other articles, so that we could fully understand it? Thank you for your work
- Sean12y ago
  see if this helps with the error with SaveAsync: public async Task SaveAsync()
Gaurav Gupta14y ago
I had updated it.. If more updation required plz suggests...
tak v14y ago
Please update your article, praveen vr is right!
Praveen VR14y ago
Hi Gourav, I seen some irrelevant coding lines in your article. You specified "UserDetails" class but never used and instantiated.Instead you specified an "Account" class for DataContractSerializer parameter.You also used undefined App.Stats for accessing Name and Id. To retrieve information from local storage you parsed Account object to "var name" that is fine. But to display result, you given Stats.Name and Stats.Id instead of name.Name and name.Id. The XAML does'nt have any field for Id and HasField for inputs.

Today we will learn how to store and retreive user details from local application data storage.

Sometimes we want to save user-related data in some application storage during his/her session. It is necessary to save user session data during navigation though various pages in an application. Anytime and for any page we need this user session data to do some processing taks. Normally we want to store user login information for his/her session, so that we can check whether he/she is authorized or not.

In Windows 8 Store apps, the developer has the ability to save user data so it can be retrieved any time during running the application or even again in running mode after being closed by the user. The data stored in Application local storage is saved even when an application is not in running mode and you can also fetch data from it when running the app again. The data in Application local storage is never lost untill the application is removed or uninstalled from the computer system.

In this article we are trying to save user data to Local Application data storage and also retrieve from it. So, now we proceed to create a Windows 8 Store blank application and save user details to Local Application data storage.

First create a Blank Application using C# and XAML.

I've created a simple blank XAML page:

<Page

x:Class="savinguserdataonsuspended.MainPage"

IsTabStop="false"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:local="using:savinguserdataonsuspended"

xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

mc:Ignorable="d">

</Canvas>

</Grid>

</Page>

Now, I need an entity for the values of these controls and then save the entire bucket to Local Application Storage. So, I'm going to create a UserDetails class.

public class UserDetail

{

public int Id { get; set; }

public string Name { get; set; }

}

I use the Button's click events to keep the instance of UserDetails updated and call a SaveAsync() method and then, navigate to another page.

UserDetail Stats = new UserDetail();

private async void login_Click_1(object sender, RoutedEventArgs e)

{

Stats.Name = NameTextBox.Text;

Stats.Id = int.Parse(IdTextBox.Text);

await SaveAsync();

this.Frame.Navigate(typeof(next));
}

You all know that everything in Windows 8 Store apps is asynchronous, so we'll see the async and await keywords in these apps.

In the SaveAsync method we will serialize the data to be saved into Local Application Storage.

StorageFile userdetailsfile = await ApplicationData.Current.LocalFolder.CreateFileAsync("UserDetails",

CreationCollisionOption.ReplaceExisting);

IRandomAccessStream raStream = await userdetailsfile.OpenAsync(FileAccessMode.ReadWrite);

using (IOutputStream outStream = raStream.GetOutputStreamAt(0))

{

// Serialize the Session State.

DataContractSerializer serializer = new DataContractSerializer(typeof(UserDetail));

serializer.WriteObject(outStream.AsStreamForWrite(), Stats);

await outStream.FlushAsync();

}

In the preceding code first we get the local folder of local storage and then create a file using the CreateFileAsync() method also user the parameter ReplaceExisting if the file already exists. Then we open it using OpenAsync in the read/write mode. Then I serialize the object using the DataContractSerializer class and write this serializer obect to a file using the WriteObject method.

In the Next Page where we naviagte after login we call the ReterieveAsync() method to restore the value back to a bucket at the OnNavigatedTo event of the page.

protected async override void OnNavigatedTo(NavigationEventArgs e)

{

await RestoreAsync();
}

Here is the code of the ReterieveAsync() method where I read the file from the Local Folder, deserialize it's contents and then set the instance of UserDetails with the values that were saved earlier.

StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync("UserDetails");

if (file == null) return;

IRandomAccessStream inStream = await file.OpenReadAsync();

// Deserialize the Session State.

DataContractSerializer serializer = new DataContractSerializer(typeof(UserDetail));

var StatsDetails = (UserDetail)serializer.ReadObject(inStream.AsStreamForRead());

inStream.Dispose();

UserName.Text ="Welcome "+ StatsDetails .Name;

UserProfileId = StatsDetails.Id;

This is what my app looks like before I close or navigate it myself.

Local-Storage-Location-In-Windows8-Apps (1).jpg