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
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Runtime.CompilerServices;
  4. using System.Threading.Tasks;
  5. using Xamarin.Forms;
  6. using System.Linq;
  7. using FetchContactsDemo.Droid;
  9. [assembly: Xamarin.Forms.Dependency(typeof(UserContactService))]
  10. namespace FetchContactsDemo.Droid
  11. {
  12. public class UserContactService : IUserContactService
  13. {
  14. private readonly Xamarin.Contacts.AddressBook _book;
  15. private static IEnumerable<MobileUserContact> _contacts;
  17. public UserContactService()
  18. {
  19. _book = new Xamarin.Contacts.AddressBook(Forms.Context.ApplicationContext);
  20. }
  22. public List<MobileUserContact> FindContacts(string searchInContactsString)
  23. {
  25. var ResultContacts = new List<MobileUserContact>();
  27. foreach (var currentContact in _contacts)
  28. {
  29. // Running a basic String Contains() search through all the
  30. // fields in each Contact in the list for the given search string
  31. if ((currentContact.Contact_FirstName != null && currentContact.Contact_FirstName.ToLower().Contains(searchInContactsString.ToLower())) ||
  32. (currentContact.Contact_LastName != null && currentContact.Contact_LastName.ToLower().Contains(searchInContactsString.ToLower())) ||
  33. (currentContact.Contact_EmailId != null && currentContact.Contact_EmailId.ToLower().Contains(searchInContactsString.ToLower())))
  34. {
  35. ResultContacts.Add(currentContact);
  36. }
  37. }
  39. return ResultContacts;
  40. }
  42. public async Task<IEnumerable<MobileUserContact>> GetAllContacts()
  43. {
  45. if (_contacts != null) return _contacts;
  48. var contacts = new List<MobileUserContact>();
  49. await _book.RequestPermission().ContinueWith(t =>
  50. {
  51. if (!t.Result)
  52. {
  53. Console.WriteLine("Sorry ! Permission was denied by user or manifest !");
  54. return;
  55. }
  56. foreach (var contact in _book.ToList())
  57. {
  58. var firstOrDefault = contact.Emails.FirstOrDefault();
  59. var number = contact.Phones.FirstOrDefault();
  61. contacts.Add (new MobileUserContact () {
  62. Contact_FirstName = contact.FirstName + "====>" + number.Number,
  63. Contact_LastName = contact.LastName,
  64. Contact_DisplayName = contact.DisplayName,
  65. Contact_EmailId = firstOrDefault != null ? firstOrDefault.Address : String.Empty,
  66. Contact_Number = number != null ? number.Number : String.Empty
  67. });
  68. }
  69. });
  71. _contacts = (from c in contacts orderby c.Contact_FirstName select c).ToList();
  73. return _contacts;
  74. }
  75. }
  76. }
Code For iOS Side
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Threading.Tasks;
  5. using FetchContactsDemo.iOS;
  7. [assembly: Xamarin.Forms.Dependency(typeof(UserContactService))]
  8. namespace FetchContactsDemo.iOS
  9. {
  10. public class UserContactService : IUserContactService
  11. {
  12. private readonly Xamarin.Contacts.AddressBook _book;
  13. private static IEnumerable<MobileUserContact> _contacts;
  14. public UserContactService()
  15. {
  16. _book = new Xamarin.Contacts.AddressBook();
  17. }
  19. public List<MobileUserContact> FindContacts(string searchInContactsString)
  20. {
  21. var ResultContacts = new List<MobileUserContact>();
  23. foreach (var currentContact in _contacts)
  24. {
  25. // Running a basic String Contains() search through all the
  26. // fields in each Contact in the list for the given search string
  27. if ((currentContact.Contact_FirstName != null && currentContact.Contact_FirstName.ToLower().Contains(searchInContactsString.ToLower())) ||
  28. (currentContact.Contact_LastName != null && currentContact.Contact_LastName.ToLower().Contains(searchInContactsString.ToLower())) ||
  29. (currentContact.Contact_EmailId != null && currentContact.Contact_EmailId.ToLower().Contains(searchInContactsString.ToLower())))
  30. {
  31. ResultContacts.Add(currentContact);
  32. }
  33. }
  35. return ResultContacts;
  36. }
  38. public async Task<IEnumerable<MobileUserContact>> GetAllContacts()
  39. {
  40. if (_contacts != null) return _contacts;
  43. var contacts = new List<MobileUserContact>();
  44. await _book.RequestPermission().ContinueWith(t =>
  45. {
  46. if (!t.Result)
  47. {
  48. Console.WriteLine("Sorry ! Permission was denied by user or manifest !");
  49. return;
  50. }
  51. foreach (var contact in _book.ToList())
  52. {
  53. var firstOrDefault = contact.Emails.FirstOrDefault();
  55. contacts.Add(new MobileUserContact()
  56. {
  57. Contact_FirstName = contact.FirstName +"===>"+ contact.LastName +"===>"+ contact.DisplayName,
  58. Contact_LastName = contact.LastName,
  59. Contact_DisplayName = contact.DisplayName,
  60. Contact_EmailId = firstOrDefault != null ? firstOrDefault.Address : String.Empty
  61. });
  62. }
  63. });
  65. _contacts = (from c in contacts orderby c.Contact_FirstName select c).ToList();
  67. return _contacts;
  68. }
  69. }
  70. }
From Forms we call method to fetch contact to create interface,
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Threading.Tasks;
  5. namespace FetchContactsDemo
  6. {
  7. public interface IUserContactService
  8. {
  9. Task<IEnumerable<MobileUserContact>> GetAllContacts();
  10. List<MobileUserContact> FindContacts(string searchInContactsString);
  11. }
  12. }
Calling Method with DependencyService,
  1. try
  2. {
  3. _contactService = DependencyService.Get<IUserContactService>();
  4. var contacts = await _contactService.GetAllContacts();
  5. ContactList = new ObservableCollection<MobileUserContact>(contacts);
  6. }
  7. catch (System.Exception ex)
  8. {
  10. }
Output
Source Code