Shared Preferences in Xamarin.forms

Question

I have tried to save login value as true if user has logged in once by using

Application.Current.Properties["isLoggedIn"] = "true";

but its not working. If i remove my app from background it again shows the login page but if user is logged in it should show the next page.

Have a look at the [settings plug](https://github.com/jamesmontemagno/SettingsPlugin) from [james montemagno](http://stackoverflow.com/users/3085228/jamesmontemagno) — Jack, Apr 19 '17 at 15:10

EvZ · Answer 1 · 2017-04-24T13:32:14.507

4

When using 'Application Properties Dictionary' you have to keep in mind few things:

According to the official documentation: 'The Properties dictionary is saved to the device automatically'. However, if you want to ensure persistence you have to explicitly call SavePropertiesAsync().
The Properties dictionary can only serialize primitive types for storage. Attempting to store other types such as List can fail silently.

Read the official documentation carefully and pay attention to details.

Here is a code example:

private async Task SaveApplicationProperty<T>(string key, T value)
{
    Xamarin.Forms.Application.Current.Properties[key] = value;
    await Xamarin.Forms.Application.Current.SavePropertiesAsync();
}

private T LoadApplicationProperty<T>(string key)
{
    return (T) Xamarin.Forms.Application.Current.Properties[key];
}

// To save your property
await SaveApplicationProperty("isLoggedIn", true);

// To load your property
bool isLoggedIn = LoadApplicationProperty<bool>("isLoggedIn");

Base on your needs you may consider Local Database or Settings Plugin instead. However for saving just a few primitive values Application Properties approach should be good enough.

edited Apr 24 '17 at 13:32

answered Apr 19 '17 at 18:55

EvZ

11,889
4
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where i have to use it?? – Priyanka singhal Apr 21 '17 at 05:34
Right after 'Application.Current.Properties["isLoggedIn"] = "true";' for example. – EvZ Apr 21 '17 at 06:43
Its not working after that its again showing login page if i remove my app from background – Priyanka singhal Apr 21 '17 at 07:41
Not sure what you mean by 'i remove my app from background' but if you await 'SavePropertiesAsync()' right after setting your value it should work, unless the app is killed in the middle of 'SavePropertiesAsync()' or uninstalled. – EvZ Apr 21 '17 at 08:07
remove my app from background means if i kill my app. so when i will come to know that it has SavePropertiesAysnc() so that i can kill my app – Priyanka singhal Apr 21 '17 at 10:47
how to call this method with "isloggedin" as key and true as value – Priyanka singhal Apr 24 '17 at 07:47
it is showing error "An object reference is required for non-static field,method or property" in the line calling await SaveApplicationProperty("isLoggedIn", true); – Priyanka singhal Apr 24 '17 at 11:37
I had a typo in the loading part, fixed now. – EvZ Apr 24 '17 at 11:41

score 2 · Answer 2 · answered Dec 04 '19 at 14:50

Xamarin Forms now includes Xamarin Forms Essentials and contains the Preferences component that you need. Check out the official website and try it. https://learn.microsoft.com/en-us/xamarin/essentials/preferences?tabs=ios

This is an example of how to manage preferences with Essentials.

To save a value for a given key in preferences:

Preferences.Set("my_key", "my_value");
To retrieve a value from preferences or a default if not set:

var myValue = Preferences.Get("my_key", "default_value");
To remove the key from preferences:

Preferences.Remove("my_key");
To remove all preferences:

Preferences.Clear();

Supported Data Types:

bool
double
int
float
long
string
DateTime

score 1 · Answer 3 · answered May 31 '22 at 08:15

1

First we set the key and value using below code

Xamarin.Essentials.Preferences.Set("UserId", content.userId);

We can get the above value in any page of project using below code

Xamarin.Essentials.Preferences.Get("UserId", "");

answered May 31 '22 at 08:15

Indian

31
3

Shared Preferences in Xamarin.forms

3 Answers3

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