Question

我正在尝试使用NSLog()将所有手机的联系人打印到控制台。目前此代码只是打印(null)。

·H

@property (nonatomic, strong) NSMutableArray *contactsObjects;

的.m

@synthesize contactsObjects;
//lazy instantiation. 
- (NSMutableArray *)contactsObjects
{
    if(!contactsObjects)
    {
        contactsObjects = [[NSMutableArray alloc]init];
    }

    return contactsObjects;
}

- (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.
                CFMutableArrayRef contactsObjects = 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.
        CFMutableArrayRef contactsObjects = 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);
}

我在这里收到两个警告：

enter image description here

我不知道为了正确地将我的联系人的姓名和号码打印到控制台，我应该做些什么。

如何打印联系人姓名和号码？

Answer 1

你说它打印出null并且你得到一个错误。但这可以解释你的错误。

contactObjects在if块和else if块中定义。因此，当您超出条件时，它就不再被定义了。

试试这个

- (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 = 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 = 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);
}

Answer 2

您的代码存在范围问题。 contactsObjects中的viewWillAppear:个变量与您调用的contactsObjects的ivar无关。您正在声明使用相同名称的新变量。另一方面，最后的NSLog()是伊瓦尔。但设置其他变量并没有在ivar中添加任何内容，因此您会看到(null)，NSLog()代表“无对象”。

通过不使用新的变量声明来修复此问题，但使用ivar。

if (granted) {
    contactsObjects = ABAddressBookCopyArrayOfAllPeople(addressBookRef);

else if (ABAddressBookGetAuthorizationStatus() == kABAuthorizationStatusAuthorized) {
    contactsObjects = ABAddressBookCopyArrayOfAllPeople(addressBookRef);

您还需要投射这些：

    contactsObjects = (__bridge_transfer NSArray *)ABAddressBookCopyArrayOfAllPeople(addressBookRef);

（此外，该函数不会返回一个可变数组，所以你可能会遇到麻烦。）

第二个问题是ABAddressBookRequestAccessWithCompletion()没有停止并等待其完成Block运行。在请求访问权限时，您的方法的其余部分会继续执行，因此在此情况下实际设置NSLog()之前，您会到达contactsObjects。

从ABAddressBookRequestAccessWithCompletion（）获取联系人数组给出nil

2 个答案: