CFDictionaryGetValue remark

这样写 会crash，莫名奇妙

                //NSString* homeAddress = [[NSString alloc ]stringWithFormat:@"%@,%@,%@" ,CFDictionaryGetValue(dict, kABPersonAddressStreetKey) , CFDictionaryGetValue(dict, kABPersonAddressCityKey),CFDictionaryGetValue(dict, kABPersonAddressCountryKey)] ;

 

这样就不会

                NSString* homeAddress = [NSString stringWithFormat:@"%@,%@,%@" ,CFDictionaryGetValue(dict, kABPersonAddressStreetKey) , CFDictionaryGetValue(dict, kABPersonAddressCityKey),CFDictionaryGetValue(dict, kABPersonAddressCountryKey)] ;

 

 

这样也crash ，参考是官方教程http://developer.apple.com/library/ios/#documentation/ContactData/Conceptual/AddressBookProgrammingGuideforiPhone/Chapters/BasicObjects.html#//apple_ref/doc/uid/TP40007744-CH3-SW1

 

        CFStringRef firstName, lastName;

        firstName = (CFStringRef)ABRecordCopyValue((ABRecordRef)people, kABPersonFirstNameProperty);

        lastName = (CFStringRef)ABRecordCopyValue((ABRecordRef)people, kABPersonLastNameProperty);

NSString *tmpName = [NSString stringWithFormat:@"%@%@", 

                             nil == lastName ? @"" : (NSString *)lastName, 

                             nil == firstName ? @"" :(NSString *)firstName];

 

        CFRelease(firstName) ;

        CFRelease(lastName) ;

 

下面这样就不会crash

 NSString *firstName = (NSString *)ABRecordCopyValue((ABRecordRef)people, kABPersonFirstNameProperty);

NSString *lastName = (NSString *)ABRecordCopyValue((ABRecordRef)people, kABPersonLastNameProperty);

NSString *tmpName = [NSString stringWithFormat:@"%@%@", 

                             nil == lastName ? @"" : (NSString *)lastName, 

                             nil == firstName ? @"" :(NSString *)firstName];

 

[firstName release]

[lastName release]