CFStringRef 版本为 nil 时提供错误访问

Question

ABMultiValueRef phonesRef = ABRecordCopyValue(person, kABPersonPhoneProperty);
    for (int i=0; i < ABMultiValueGetCount(phonesRef); i++)
    {
        CFStringRef currentPhoneLabel = ABMultiValueCopyLabelAtIndex(phonesRef, i);
        CFStringRef currentPhoneValue = ABMultiValueCopyValueAtIndex(phonesRef, i);

        if (currentPhoneLabel != nil && currentPhoneValue != nil)
        {
            if (CFStringCompare(currentPhoneLabel, kABPersonPhoneMobileLabel, 0) == kCFCompareEqualTo)
            {
                [contactInfoDict setObject:(__bridge NSString *)currentPhoneValue forKey:@"workNumber"];
            }

            if (CFStringCompare(currentPhoneLabel, kABHomeLabel, 0) == kCFCompareEqualTo)
            {
                [contactInfoDict setObject:(__bridge NSString *)currentPhoneValue forKey:@"homeNumber"];
            }
        }
        else if (currentPhoneValue != nil && currentPhoneLabel == nil)
        {
            [contactInfoDict setObject:(__bridge NSString *)currentPhoneValue forKey:@"workNumber"];
        }

        CFRelease(currentPhoneLabel);
        CFRelease(currentPhoneValue);
    }
    CFRelease(phonesRef);

这是我的代码，用于将联系电话导入我的 ios 应用程序，但是当 currentPhoneLabel 为 CFRelease(currentPhoneLabel) 的 nil xocde 时。我不知道为什么会这样。任何帮助将不胜感激。

谢谢

Answer 1

你在代码的其他地方已经有了守卫，所以你只需要在每次调用 CFRelease() 时也添加一个守卫：

if (currentPhoneLabel != NULL)
    CFRelease(currentPhoneLabel);
// etc.

CFStringRef 版本为 nil 时提供错误访问

CFStringRef release gives bad access when it is nil

objective-c

cfstring

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xcode7