如何在tableview中显示联系人 - 目标C.

Question

我想创建一个程序，它将从adressbook导入联系人并在tableview中显示它们。 我已经完成了从adressbook下载联系人的代码，但是当我将它们添加到Array中然后尝试在TableView中显示时，它们就不会在我启动应用程序时出现。 这是代码：

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [self getPersonOutOfAddressBook];
    [super viewDidLoad];


    // Do any additional setup after loading the view, typically from a nib.
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.tableData count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"Identifier";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }

    Person *person = [self.tableData objectAtIndex:indexPath.row];
    cell.textLabel.text = person.fullName;

    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

}
- (void)getPersonOutOfAddressBook
{
    //1
    CFErrorRef error = NULL;
    ABAddressBookRef addressBook = ABAddressBookCreateWithOptions(NULL, &error);
    __block BOOL accessGranted = NO;

    if (ABAddressBookRequestAccessWithCompletion != NULL) { // We are on iOS 6
        dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);

        ABAddressBookRequestAccessWithCompletion(addressBook, ^(bool granted, CFErrorRef error) {
            accessGranted = granted;
            dispatch_semaphore_signal(semaphore);
        });
    }
    if (addressBook != nil) {
        NSLog(@"Succesful.");

        //2
        NSArray *allContacts = (__bridge_transfer NSArray *)ABAddressBookCopyArrayOfAllPeople(addressBook);

        //3
        NSUInteger i = 0; for (i = 0; i < [allContacts count]; i++)
        {
            Person *person = [[Person alloc] init];
            ABRecordRef contactPerson = (__bridge ABRecordRef)allContacts[i];

            //4
            NSString *firstName = (__bridge_transfer NSString *)ABRecordCopyValue(contactPerson,
                                                                                  kABPersonFirstNameProperty);
            NSString *lastName = (__bridge_transfer NSString *)ABRecordCopyValue(contactPerson, kABPersonLastNameProperty);
            NSString *fullName = [NSString stringWithFormat:@"%@ %@", firstName, lastName];

            person.firstName = firstName; person.lastName = lastName;
            person.fullName = fullName;

            [self.tableData addObject:person];
        }

        //8
        CFRelease(addressBook);
    } else { 
        //9
        NSLog(@"Error reading Address Book");
    } 
}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

当我使用调试器时，它显示变量firstname，lastname和fullname可以访问adressbook，因为我可以看到person的名字或姓氏。 但我认为添加到数组有问题因为我在这个数组中看不到任何东西。 有人能帮助我吗？ 我是Objective-C的初学者所以请忍耐:)

Answer 1

要使用数组，您需要声明它并创建它。 您可以通过分配和初始化数组来完成此操作。

self.tableData = [[NSMutableArray alloc] init];