外企的一个面试题，展示，添加，联系人列表

添加联系人:

#import "AddContactViewController.h"
        #import "AppDelegate.h"
        #import "Contact+Create.h"

@interface AddContactViewController ()

@property (nonatomic, strong) NSManagedObjectContext *context;

@end

@implementation AddContactViewController
@synthesize context = _context;

        - (void)loadView
        {
        self.view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];
        UITextField *nameTextField = [[UITextField alloc] initWithFrame:CGRectMake(20.0f, 20.0f, 280.0f, 44.0f)];
        nameTextField.placeholder = @"姓名";
        nameTextField.tag = 100;
        [self.view addSubview:nameTextField];

        UITextField *abbreviationTextField = [[UITextField alloc] initWithFrame:CGRectMake(20.0f, 80.0f, 280.0f, 44.0f)];
        abbreviationTextField.placeholder = @"姓名缩写 请输入字母";
        abbreviationTextField.tag = 101;
        [self.view addSubview:abbreviationTextField];

        }

        - (void)viewDidLoad
        {
        [super viewDidLoad];

        self.context = ((AppDelegate *)[UIApplication sharedApplication].delegate).managedObjectContext;

        self.navigationItem.title = @"添加联系人";
        self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSave target:self action:@selector(save)];

        }

        - (void)save
        {
        UITextField *nameTextField = (UITextField *)[self.view viewWithTag:100];
        UITextField *abbreviationTextField = (UITextField *)[self.view viewWithTag:101];
        if ([nameTextField.text length] > 0 && [abbreviationTextField.text length] == 1) { //  text type checking ？？ ！！！ YES!
        NSInteger unique = arc4random()%100000;
        NSString *uniqueTemp = [NSString stringWithFormat:@"%d",unique]; // unique? need to  enter unique numner is unique . Haha..!
        NSMutableDictionary *dic = [NSMutableDictionary dictionaryWithObjectsAndKeys:nameTextField.text, @"name", abbreviationTextField.text, @"abbreviation", uniqueTemp , @"unique", nil];
        [Contact saveContactWithDictionary:dic InManagedObjectContext:self.context];
        [self.navigationController popViewControllerAnimated:YES];
        } else {
        NSLog(@"sleep..oop...");
        }
        }


@end

MainList方式:

#import "ContactListViewController.h"
        #import "AppDelegate.h"
        #import "Tool.h"
        #import "UIImageView+WebCache.h"
        #import "ContactViewController.h"
        #import "AddContactViewController.h"

@interface ContactListViewController ()<UITableViewDataSource, UITableViewDelegate, NSFetchedResultsControllerDelegate>

@property (nonatomic, strong) UITableView *tableView;
@property (nonatomic, strong) NSManagedObjectContext *context;
@property (nonatomic, strong) NSFetchedResultsController*fetchedResultsController;
@property (nonatomic, strong) NSArray *sectionTitle;

@end

@implementation ContactListViewController
@synthesize tableView = _tableView;
@synthesize context = _context;
@synthesize fetchedResultsController = _fetchedResultsController;
@synthesize sectionTitle = _sectionTitle;


        #pragma mark -
        #pragma mark - Private

        - (void)addContact // write a simple example , only need to fill in NAME
        {
        AddContactViewController *addContactViewController = [[AddContactViewController alloc] init];
        [self.navigationController pushViewController:addContactViewController animated:YES];
        // maybe use present*** ，this is the most logical answer in my view.
        }

        - (NSFetchedResultsController *)fetchedResultsController
        {
        if (_fetchedResultsController != nil) {
        return _fetchedResultsController;
        }
        NSFetchRequest *request = [NSFetchRequest fetchRequestWithEntityName:@"Contact"];
        request.sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"abbreviation" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)]];
        _fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:self.context sectionNameKeyPath:@"abbreviation" cacheName:nil];
        _fetchedResultsController.delegate = self;
        [_fetchedResultsController performFetch:NULL];
        return _fetchedResultsController;

        }

        #pragma mark -
        #pragma mark - Life

        - (void)loadView
        {
        self.view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];

        self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 416.0f) style:UITableViewStylePlain];
        self.tableView.delegate = self;
        self.tableView.dataSource = self;
        [self.view addSubview:self.tableView];
        }

        - (void)viewDidLoad
        {
        [super viewDidLoad];

        self.context = ((AppDelegate *)[UIApplication sharedApplication].delegate).managedObjectContext;

        self.navigationItem.title = @"联系人";
        self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addContact)];

        //create text data
        [Tool createTextDataWithManagedObjectContext:self.context];
        self.sectionTitle = [Tool createSectionNameTitles];
        }


        #pragma mark -
        #pragma mark - UITableView

        - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
        {
        return [[self.fetchedResultsController sections] count];
        }

        - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
        {
        return [[[self.fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
        }

        - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
        {
        return [[[self.fetchedResultsController sections] objectAtIndex:section] name];
        }

        - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index
        {
        if ([self.fetchedResultsController.sectionIndexTitles containsObject:title]) {
        NSLog(@"index %d",index);
        NSInteger newIndex = [self.fetchedResultsController.sectionIndexTitles indexOfObject:title];
        NSLog(@"newindex %d",newIndex);
        return [self.fetchedResultsController sectionForSectionIndexTitle:title atIndex:newIndex];
        } else {
        return 0;
        }
        }

        - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
        {
        return self.sectionTitle;
        }

        - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
        {
static NSString *CellIdentifier = @"ContactListCell";
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        }
        Contact *contact = [self.fetchedResultsController objectAtIndexPath:indexPath];
        cell.textLabel.text = contact.name;
        [cell.imageView setImageWithURL:[NSURL URLWithString:contact.avatar] placeholderImage:[UIImage imageNamed:@"touxiang"]];
        return cell;
        }

        - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
        {
        return 45.0f;
        }

        - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
        {
        Contact *contact = [self.fetchedResultsController objectAtIndexPath:indexPath];
        ContactViewController *contactViewController = [[ContactViewController alloc] initWithContact:contact];
        [self.navigationController pushViewController:contactViewController animated:YES];
        }

        #pragma mark - NSFetchedResultControllerDelegate

        - (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
        {
        [self.tableView beginUpdates];
        }

        - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id<NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
        {
        switch (type) {
        case NSFetchedResultsChangeInsert:
        [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
        break;
        case NSFetchedResultsChangeDelete:
        [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
        break;
default:
        break;
        }
        }

        - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath
        {
        switch (type) {
        case NSFetchedResultsChangeInsert:
        [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
        break;
        case NSFetchedResultsChangeDelete:
        [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
        break;
        case NSFetchedResultsChangeMove:
        [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
        break;
        case NSFetchedResultsChangeUpdate:
        [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        break;
default:
        break;
        }

        }

        - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
        {
        [self.tableView endUpdates];
        }


@end

contact的一个item显示:

#import "ContactViewController.h"
        #import "UIImageView+WebCache.h"

@interface ContactViewController ()

@property (nonatomic, strong) Contact *contact;
@end

@implementation ContactViewController
@synthesize contact = _contact;

        #pragma mark- Life

        - (id)initWithContact:(Contact *)contact
        {
        if (self = [super init]) {
        self.contact = contact;
        }
        return self;
        }

        - (void)loadView
        {
        self.view = [[UIView alloc] initWithFrame:[UIScreen mainScreen].bounds];

        self.navigationItem.title = self.contact.name;

        UIImageView *avatarView = [[UIImageView alloc] initWithFrame:CGRectMake(10.0f, 10.0f, 45.0f, 45.0f)];
        [avatarView setImageWithURL:[NSURL URLWithString:self.contact.avatar] placeholderImage:[UIImage imageNamed:@"touxiang"]];
        [self.view addSubview:avatarView];

        UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(65.0f, 10.0f, 130.0f, 22.0f)];
        nameLabel.text = self.contact.name;
        [self.view addSubview:nameLabel];

        UILabel *mobileLabel = [[UILabel alloc] initWithFrame:CGRectMake(65.0f, 100.0f, 160.0f, 22.0f)];
        mobileLabel.text = self.contact.mobile;
        [self.view addSubview:mobileLabel];

        //............. add all information from self.contact.name .  If we need to edit , we can use textField;

        }

        - (void)viewDidLoad
        {
        [super viewDidLoad];
        }


@end

代码上传到https://download.csdn.net/download/baidu_nod/10837941