使用NSLog將控制檯打印到地址簿

Question

我在我的viewWillAppear:中使用此命令將我的所有聯繫人姓名和號碼打印到控制檯。

- (void)viewWillAppear:(BOOL)animated 
{ 
    CFErrorRef error = nil; 
    // Request authorization to Address Book 
    ABAddressBookRef addressBookRef = ABAddressBookCreateWithOptions(NULL, &error); 

    if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusNotDetermined) { 
     ABAddressBookRequestAccessWithCompletion(addressBookRef, ^(bool granted, CFErrorRef error) 
     { 
      if (granted) { 
       // First time access has been granted, add all the user's contacts to array. 

       contactsObjects = (__bridge NSMutableArray *)(ABAddressBookCopyArrayOfAllPeople(addressBookRef)); 
      } else { 
       // User denied access. 
       // Display an alert telling user that they must allow access to proceed to the "invites" page. 
      } 
     }); 
    } 
    else if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusAuthorized) { 
     // The user has previously given access, add all the user's contacts to array. 

     contactsObjects = (__bridge NSMutableArray *)(ABAddressBookCopyArrayOfAllPeople(addressBookRef)); 
    } 
    else { 
     // The user has previously denied access 
     // Send an alert telling user that they must allow access to proceed to the "invites" page. 
    } 

    NSLog(@"%@", contactsObjects); 
} 

和這裏的輸出

與此錯誤消息：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType length]: unrecognized selector sent to instance 0x16ec2190'*** 

什麼問題？

編輯與斷點在拋出異常發現問題： FULL .M：

@synthesize inviteTableSearchBar; 

@synthesize contactsObjects; 
@synthesize facebookObjects; 
@synthesize twitterObjects; 
@synthesize searchResults; 

//lazy instantiations <below>------- 
- (NSArray *)contactsObjects 
{ 
    if(!contactsObjects) 
    { 
     contactsObjects = [[NSArray alloc]init]; 
    } 

    return contactsObjects; 
} 

- (NSMutableArray *)searchResults 
{ 
    if(!searchResults) 
    { 
     searchResults = [[NSMutableArray alloc]init]; 
    } 

    return searchResults; 
} 
//lazy instantiations <above>------- 

- (id)initWithStyle:(UITableViewStyle)style 
{ 
    self = [super initWithStyle:style]; 
    if (self) { 
     // Custom initialization 
    } 
    return self; 
} 

- (void)viewWillAppear:(BOOL)animated 
{ 
    CFErrorRef error = nil; 
    // Request authorization to Address Book 
    ABAddressBookRef addressBookRef = ABAddressBookCreateWithOptions(NULL, &error); 

    if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusNotDetermined) { 
     ABAddressBookRequestAccessWithCompletion(addressBookRef, ^(bool granted, CFErrorRef error) 
     { 
      if (granted) { 
       // First time access has been granted, add all the user's contacts to array. 

       contactsObjects = (__bridge_transfer NSArray *)(ABAddressBookCopyArrayOfAllPeople(addressBookRef)); 
      } else { 
       // User denied access. 
       // Display an alert telling user that they must allow access to proceed to the "invites" page. 
      } 
     }); 
    } 
    else if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusAuthorized) { 
     // The user has previously given access, add all the user's contacts to array. 

     contactsObjects = (__bridge_transfer NSMutableArray *)(ABAddressBookCopyArrayOfAllPeople(addressBookRef)); 
    } 
    else { 
     // The user has previously denied access 
     // Send an alert telling user that they must allow access to proceed to the "invites" page. 
    } 

    NSLog(@"%@", contactsObjects); 
} 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    //CUSTOM APPEARANCE <below> 

    //set in order to actually change the search bar's UIColor. 
    [self.inviteTableSearchBar setBackgroundImage:[UIImage new]]; 
    [self.inviteTableSearchBar setTranslucent:YES]; 

    self.inviteTableSearchBar.backgroundColor = [UIColor colorWithHexString:@"#333333"]; 
    [[UILabel appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor colorWithHexString:@"#669900"]]; 

    //Uncomment the following line to preserve selection between presentations; YES to clear tableView when the tableViewController recieves `viewWillAppear:` 
    self.clearsSelectionOnViewWillAppear = YES; 

    //Fill array 
    //[self.contactsObjects addObject:@"Examples<below>"]; 
    //[self.contactsObjects addObject:@"John"]; 
    //[self.contactsObjects addObject:@"Sanford"]; 
    //[self.contactsObjects addObject:@"Sally"]; 
    //[self.contactsObjects addObject:@"Susan B. Anthony"]; 

    // Hide the search bar until user scrolls up 
    CGRect newBounds = self.tableView.bounds; 
    newBounds.origin.y = newBounds.origin.y + inviteTableSearchBar.bounds.size.height; 
    self.tableView.bounds = newBounds; 

} 

- (void)didReceiveMemoryWarning 
{ 
    [super didReceiveMemoryWarning]; 
    // Dispose of any resources that can be recreated. 
} 

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{ 
    return 1; 
} 

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{ 
    return self.contactsObjects.count; 
} 

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

    //configure the cells 
    cell.textLabel.text = self.contactsObjects[indexPath.row]; 

    return cell; 
} 

問題是cell.textLabel.text = self.contactsObjects[indexPath.row];的//configure the cells下方。在cellForRowAtIndexPath:方法中。

Answer 1

#define CHECK_NULL_STRING(str) ([str isKindOfClass:[NSNull class]] || !str)?@"":str 

id p=[contactsObjects objectAtIndex:indexPath.row]; 
    NSString *fName=(__bridge NSString *)(ABRecordCopyValue((__bridge ABRecordRef)(p), kABPersonSortByFirstName)); 
     NSString *lName=(__bridge NSString *)(ABRecordCopyValue((__bridge ABRecordRef)(p), kABPersonSortByLastName)); 
cell.textLabel.text=[NSString stringWithFormat:@"%@ %@",CHECK_NULL_STRING(fName),CHECK_NULL_STRING(lName)] 

Answer 2

這意味着您試圖詢問地址0x175c4b10處的對象的長度，但它不是響應方法length的對象。該錯誤可能不在您發佈的代碼中，因爲您沒有在那裏調用length方法。可能是因爲你在其他地方打電話給length（在你的代碼中搜索你的位置），或者你可能調用了一個最終調用length的方法，但是你傳遞了一個無效的參數。