的iOS - 內存泄露通訊錄

Question

我工作圍繞通訊錄框架時，我發現了不同類型的一些內存泄漏在我的應用程序：

Leaked Object # Address Size Responsible Library Responsible Frame 
__NSCFArray 8 <multiple> 256 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 
__NSCFString 7 <multiple> 224 Bytes AppSupport _sqliteStatementApplyValuesFromRecordWithNullValue 
Malloc 32 Bytes 8 <multiple> 256 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 
__NSCFArray 8 <multiple> 256 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 
ABCMultiValue 8 <multiple> 256 Bytes AddressBook ABCMultiValueCreate 
Malloc 32 Bytes 7 <multiple> 224 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 
__NSCFArray 7 <multiple> 224 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 
Malloc 32 Bytes 5 <multiple> 160 Bytes AddressBook ABCMultiValueInsertAndCreateIdentifier 

這裏是我的代碼：

- (BOOL)peoplePickerNavigationController:(ABPeoplePickerNavigationController *)peoplePicker shouldContinueAfterSelectingPerson:(ABRecordRef)person { 

    SDAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate]; 

    ABMultiValueRef multiRef = ABRecordCopyValue(person, kABPersonPhoneProperty); 
    NSString *number = (__bridge NSString *) ABMultiValueCopyValueAtIndex(multiRef, 0); 
    NSString *firstname = (__bridge NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty); 
    NSString *lastname = (__bridge NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty); 

    number = (number ? number : @""); 
    firstname = (firstname ? firstname : @""); 
    lastname = (lastname ? lastname : @""); 

    NSDictionary *dic = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:number, firstname, lastname, nil] forKeys:[NSArray arrayWithObjects:kSDPhoneNumberKey, kSDFirstnameKey, kSDLastnameKey, nil]]; 

    NSMutableArray *numberArray = [NSMutableArray arrayWithArray:appDelegate.contactArray]; 
    [numberArray addObject:dic]; 

    [appDelegate setContactArray:numberArray]; 

    [self.tableView reloadData]; 

    [self dismissModalViewControllerAnimated:YES]; 

    return NO; 
} 

做別人知道哪些線路是造成這些泄漏的原因？

Answer 1

一般而言，名稱中含有Copy或Create的任何Core Foundation方法應將所有權轉讓給您的ARC對象，或者您必須自行撥打CFRelease。因此，您應該爲您的三個NSString對象轉讓所有權，並手動發佈multiRef。

爲了將所有權轉讓給ARC你應該使用CFBridgingRelease，它根據WWDC 2012 - Modern Objective-C（約37:35到視頻），現優於以前的技術，__bridging_transfer（儘管，在幕後，它們是相同的事情）。

無論如何，你的三個NSString對象的聲明應該是：

NSString *number = CFBridgingRelease(ABMultiValueCopyValueAtIndex(multiRef, 0)); 
NSString *firstname = CFBridgingRelease(ABRecordCopyValue(person, kABPersonFirstNameProperty)); 
NSString *lastname = CFBridgingRelease(ABRecordCopyValue(person, kABPersonLastNameProperty)); 

這相當於：

NSString *number = (__bridge_transfer NSString *) ABMultiValueCopyValueAtIndex(multiRef, 0); 
NSString *firstname = (__bridge_transfer NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty); 
NSString *lastname = (__bridge_transfer NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty); 

另外，不要忘記釋放multiRef，太：

CFRelease(multiRef); 

順便說一下，如果你運行了靜態分析器，我相信它會爲你指出這些。從「產品」菜單中選擇「分析」，或按移位 + 命令 + B。