Xamarin Android: Create Android ISharedPreferences App

Introduction

This application is to create and maintain Session Values in Xamarin Android.

Let’s start

Step 1

Open Visual Studio, New Project, Templates, Visual C#, Android, Blank App, Select Blank App (Android). Then give Project Name and Project Location.



Step 2 - Next go to Solution Explorer-> Project Name then Right Click to Add->Class and open new Dialog box.



Step 3 - Dialog box to select Class and give the Name AppPreferences.cs,

Step 4 - Next, Open Solution Explorer, Project Name, Resources, AppPreferences.cs. Click to open the following code. 

C# Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Preferences; //Add New NameSpace
namespace SharedPreference
{
public class AppPreferences
{
 private ISharedPreferences nameSharedPrefs;
  private ISharedPreferencesEditor namePrefsEditor; //Declare Context,Prefrences name and Editor name
  private Context mContext;
  private static String PREFERENCE_ACCESS_KEY = "PREFERENCE_ACCESS_KEY"; //Value Access Key Name
  public static String NAME = "NAME"; //Value Variable Name
  public AppPreferences(Context context)
  {
  this.mContext = context;
  nameSharedPrefs = PreferenceManager.GetDefaultSharedPreferences(mContext);
  namePrefsEditor = nameSharedPrefs.Edit();
  }
  public void saveAccessKey(string key) // Save data Values
  {
  namePrefsEditor.PutString(PREFERENCE_ACCESS_KEY, key);
  namePrefsEditor.Commit();
  }
  public string getAccessKey() // Return Get the Value
  {
  return nameSharedPrefs.GetString(PREFERENCE_ACCESS_KEY, "");
  }
  }
  }

Step 5

Then Open Solution Explorer, Project Name, Resources, layout, Main.axml, then click open Design View. Select Toolbar, then Drag and Drop design of Buttons, TextView, PlainText.

XML Code

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

<TextView

android:text="Enter Name"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/Text" />

<EditText

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/txtsave" />

<Button

android:text="Save"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/btnsave" />

<TextView

android:text="GET SAVED NAME"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/textView2" />

<TextView

android:text=""

android:textAppearance="?android:attr/textAppearanceLarge"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/txtgetname" />

<Button

android:text=" GET STORED DATA"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/btnget" />

<Button

android:text="Delete Preferences"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:id="@+id/btnreset" />

</LinearLayout>

Step 6

Then open Solution Explorer, Project Name, MainActivity.cs. Click to open C# Code page. Then go to section OnCreate() and declare create Button, TextView and EditText Events.

C# Code

using System;

using Android.App;

using Android.Content;

using Android.Runtime;

using Android.Views;

using Android.Widget;

using Android.OS;

using Android.Preferences;

namespace SharedPreference

{

[Activity(Label = "SharedPreference", MainLauncher = true, Icon = "@drawable/icon")]

public class MainActivity : Activity

{

Button btnsave;

Button btnget;

Button btnreset;

EditText txtname;

TextView txtview;

protected override void OnCreate(Bundle bundle)

{

base.OnCreate(bundle);

// Set our view from the "main" layout resource

SetContentView(Resource.Layout.Main);

// Get our button from the layout resource,

// and attach an event to it

btnsave = FindViewById<Button>(Resource.Id.btnsave);

btnget = FindViewById<Button>(Resource.Id.btnget);

btnreset = FindViewById<Button>(Resource.Id.btnreset);

txtname = FindViewById<EditText>(Resource.Id.txtsave);

txtview = FindViewById<TextView>(Resource.Id.txtgetname);

btnsave.Click += Btnsave_Click;

btnget.Click += Btnget_Click;

btnreset.Click += Btnreset_Click;

}

}

Step 7

Next to create Save Button Event, save the entered text in textbox values. It is the value to maintain Session of AppPreferences.

C# Code

private void Btnsave_Click(object sender, EventArgs e)

{

//Save Sessionvalue

Context mContext = Android.App.Application.Context;

AppPreferences ap = new AppPreferences(mContext);

ap.saveAccessKey(txtname.Text);

txtname.Text = "";

}

Step 8 

Next to create Get Button Event, this event work to retrieve the AppPreferences stored value. After Retrieve Value it will display in TextView.

 

C# Code

private void Btnget_Click(object sender, EventArgs e)
{

//Get Sessionvalue

Context mContext = Android.App.Application.Context;

AppPreferences ap = new AppPreferences(mContext);

string key = ap.getAccessKey();

txtview.Text = key.ToString();

}

Step 9 - Next to create Reset Button Event, this event would work with remove stored value in specified ACCESS_KEY.

C# Code

private void Btnreset_Click(object sender, EventArgs e)
  {
ISharedPreferences pref = PreferenceManager.GetDefaultSharedPreferences(this);
 ISharedPreferencesEditor editer = pref.Edit();
  editer.Remove("PREFERENCE_ACCESS_KEY").Commit(); ////Remove Spec key values
  }

Step 10 - Press F5 or Build and Run the Application.

 

 

Click Delete Preferences button to remove Session values.

Finally, we successfully created Xamarin Android SharedPreferences(AppPreferences) Application.