Fetch Contact In Xamarin.Forms

For fetching contacts we need to code platform specifically so I plan to write a code to fetch all contact lists and create a demo on it. All developers can easily access it in Xamarin Forms Project .

Code For Android Side

using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using Xamarin.Forms;
using System.Linq;
using FetchContactsDemo.Droid;
[assembly: Xamarin.Forms.Dependency(typeof(UserContactService))]
namespace FetchContactsDemo.Droid
{
public class UserContactService : IUserContactService
{
private readonly Xamarin.Contacts.AddressBook _book;
private static IEnumerable<MobileUserContact> _contacts;
public UserContactService()
{
_book = new Xamarin.Contacts.AddressBook(Forms.Context.ApplicationContext);
}
public List<MobileUserContact> FindContacts(string searchInContactsString)
{
var ResultContacts = new List<MobileUserContact>();
foreach (var currentContact in _contacts)
{
// Running a basic String Contains() search through all the
// fields in each Contact in the list for the given search string
if ((currentContact.Contact_FirstName != null && currentContact.Contact_FirstName.ToLower().Contains(searchInContactsString.ToLower())) ||
(currentContact.Contact_LastName != null && currentContact.Contact_LastName.ToLower().Contains(searchInContactsString.ToLower())) ||
(currentContact.Contact_EmailId != null && currentContact.Contact_EmailId.ToLower().Contains(searchInContactsString.ToLower())))
{
ResultContacts.Add(currentContact);
}
}
return ResultContacts;
}
public async Task<IEnumerable<MobileUserContact>> GetAllContacts()
{
if (_contacts != null) return _contacts;
var contacts = new List<MobileUserContact>();
await _book.RequestPermission().ContinueWith(t =>
{
if (!t.Result)
{
Console.WriteLine("Sorry ! Permission was denied by user or manifest !");
return;
}
foreach (var contact in _book.ToList())
{
var firstOrDefault = contact.Emails.FirstOrDefault();
var number = contact.Phones.FirstOrDefault();
contacts.Add (new MobileUserContact () {
Contact_FirstName = contact.FirstName + "====>" + number.Number,
Contact_LastName = contact.LastName,
Contact_DisplayName = contact.DisplayName,
Contact_EmailId = firstOrDefault != null ? firstOrDefault.Address : String.Empty,
Contact_Number = number != null ? number.Number : String.Empty
});
}
});
_contacts = (from c in contacts orderby c.Contact_FirstName select c).ToList();
return _contacts;
}
}
}

Code For iOS Side

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using FetchContactsDemo.iOS;
[assembly: Xamarin.Forms.Dependency(typeof(UserContactService))]
namespace FetchContactsDemo.iOS
{
public class UserContactService : IUserContactService
{
private readonly Xamarin.Contacts.AddressBook _book;
private static IEnumerable<MobileUserContact> _contacts;
public UserContactService()
{
_book = new Xamarin.Contacts.AddressBook();
}
public List<MobileUserContact> FindContacts(string searchInContactsString)
{
var ResultContacts = new List<MobileUserContact>();
foreach (var currentContact in _contacts)
{
// Running a basic String Contains() search through all the
// fields in each Contact in the list for the given search string
if ((currentContact.Contact_FirstName != null && currentContact.Contact_FirstName.ToLower().Contains(searchInContactsString.ToLower())) ||
(currentContact.Contact_LastName != null && currentContact.Contact_LastName.ToLower().Contains(searchInContactsString.ToLower())) ||
(currentContact.Contact_EmailId != null && currentContact.Contact_EmailId.ToLower().Contains(searchInContactsString.ToLower())))
{
ResultContacts.Add(currentContact);
}
}
return ResultContacts;
}
public async Task<IEnumerable<MobileUserContact>> GetAllContacts()
{
if (_contacts != null) return _contacts;
var contacts = new List<MobileUserContact>();
await _book.RequestPermission().ContinueWith(t =>
{
if (!t.Result)
{
Console.WriteLine("Sorry ! Permission was denied by user or manifest !");
return;
}
foreach (var contact in _book.ToList())
{
var firstOrDefault = contact.Emails.FirstOrDefault();
contacts.Add(new MobileUserContact()
{
Contact_FirstName = contact.FirstName +"===>"+ contact.LastName +"===>"+ contact.DisplayName,
Contact_LastName = contact.LastName,
Contact_DisplayName = contact.DisplayName,
Contact_EmailId = firstOrDefault != null ? firstOrDefault.Address : String.Empty
});
}
});
_contacts = (from c in contacts orderby c.Contact_FirstName select c).ToList();
return _contacts;
}
}
}

From Forms we call method to fetch contact to create interface,

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
namespace FetchContactsDemo
{
public interface IUserContactService
{
Task<IEnumerable<MobileUserContact>> GetAllContacts();
List<MobileUserContact> FindContacts(string searchInContactsString);
}
}

Calling Method with DependencyService,

try
{
_contactService = DependencyService.Get<IUserContactService>();
var contacts = await _contactService.GetAllContacts();
ContactList = new ObservableCollection<MobileUserContact>(contacts);
}
catch (System.Exception ex)
{
}

Output

Source Code