导入地址簿联系信息，如何处理空字段？

Question

我导入联系人信息到一些文本框，但应用程序崩溃，如果有某些方面的任何条目，如电话，电子邮件等

这里是我的文本框：

First Name 
    Middle Name 
    Last Name 

    Main Phone 
    Mobile Phone 

    Email Address 

    Website 

假设所选联系人不会有第二个电话号码（在这种情况下为手机），或者没有该联系人的URL条目。该应用程序崩溃。

*ABMutableMultiValueRef phoneMulti = ABRecordCopyValue(person, kABPersonPhoneProperty); 
NSMutableArray *phones = [[NSMutableArray alloc] init]; 
int i; 
for (i = 0; i < ABMultiValueGetCount(phoneMulti); i++) { 
    NSString *aPhone = [(NSString*)ABMultiValueCopyValueAtIndex(phoneMulti, i) autorelease];   
    [phones addObject:aPhone]; 
} 

accountPhone1TextField.text = [phones objectAtIndex:0]; 
accountPhone2TextField.text = [phones objectAtIndex:1]; 
CFRelease(phoneMulti); 
[phones release];* 

或者，如果我试图从该联系人的电子邮件地址，它不存在，这将崩溃：

NSString *anEmail = [(NSString*)ABMultiValueCopyValueAtIndex(emailMulti, i) autorelease]; 
//Variable is not a CFString 

***** UPDATE *****

结束了使用下面的代码：

ABMutableMultiValueRef emailMulti = ABRecordCopyValue(person, kABPersonEmailProperty); 
NSMutableDictionary *myEmailDict = [NSMutableDictionary dictionaryWithCapacity:ABMultiValueGetCount(emailMulti)]; 
for (CFIndex i = 0; i < ABMultiValueGetCount(emailMulti); i++) { 
    emailLabel = ABAddressBookCopyLocalizedLabel(ABMultiValueCopyLabelAtIndex(emailMulti, i)); 
    email = ABMultiValueCopyValueAtIndex(emailMulti, i); 
    [myEmailDict setObject:(NSString*)email forKey:(NSString*)emailLabel]; 
    CFRelease(email); 
    CFRelease(emailLabel); 
} 

Answer 1

if (phones.count > 0) { 
    accountPhone1TextField.text = [phones objectAtIndex:0]; 
} 
if (phones.count > 1) { 
    accountPhone2TextField.text = [phones objectAtIndex:1]; 
}