cocoa - NSArray objectAtIndex 不工作。请帮忙

Question

NSArray* address = [NSArray arrayWithArray:[detailItem addressArray]];
NSLog(@"address = %@", address);
NSString* addressToString = @"";
int arrayCount = [address count];
for (int i = 0; i < arrayCount; i++) {
    addressToString = [addressToString stringByAppendingString:[address objectAtIndex:i]];
    if (i == arrayCount -1) {
        addressToString = [addressToString stringByAppendingString:@""];
    } else {
        addressToString = [addressToString stringByAppendingString:@", "];
    }       
}

address 是一个保存地址的 NSArray

2010-06-23 09:05:19.346 iPhoneExample[1093:207] address = (
        {
        City = "Cupertino";
        Country = "United States";
        CountryCode = us;
        State = CA;
        Street = "1 Infinite Loop";
        ZIP = 95014;
    }
)

我正在尝试通过数组并创建一个 CSV 字符串，所以它看起来像

Cupertino, "United States", us, CA, "1 Infinite Loop", 95014

但是，我一直在崩溃

addressToString = [addressToString stringByAppendingString:@", "];

我得到的消息是

*** -[NSCFDictionary stringByAppendingString:]：无法识别的选择器发送到实例 0x1c2f10

更新：detailItem 是 ABContact 类型的对象（自定义类）。

ABContact 有一个名为 addressArray 的属性

@property (nonatomic, readonly) NSArray *addressArray;

我的 addressArray 的定义是

- (NSArray *) addressArray {return [self arrayForProperty:kABPersonAddressProperty];}

Answer 1

您的“地址”是 NSDictionary 的 NSArray，而不是 NSArray 的 NSArray。

要将字典的值作为数组获取，您可以使用

[theDictionary allValues]

但不能保证订单。我认为你真正需要的是：

NSMutableString* addressToString = [NSMutableString string];  // use mutable string!
for (NSDictionary* item in address) {     // use fast enumeration!
  [addressToString appendFormat:@"%@, \"%@\", %@, %@, \"%@\", %@\n",
   [item objectForKey:@"City"], 
   /* etc ... */
  ];
}

Answer 2

这个：

2010-06-23 09:05:19.346 iPhoneExample[1093:207] address = (
    {
    City = "Cupertino";
    Country = "United States";
    CountryCode = us;
    State = CA;
    Street = "1 Infinite Loop";
    ZIP = 95014;
}
)

是一个NSDictionary。您将希望通过以下方式访问其成员[dictionary objectForKey:'City']

因此，您更新的代码应为：

NSDictionary* address = [detailItem addressArray];
NSLog(@"address = %@", address);
NSString* addressToString = @"";
int counter = 0;
for (id object in myDictionary) {
  if (counter != 0)
    addressToString = [addressToString stringByAppendingString:@","];
  addressToString = [addressToString stringByAppendingString:object];   
  counter++;
}

Answer 3

如果您可以更改addressArray方法以实际返回数组而不是字典，那么您可以这样做：

NSString * addressString = [[detailItem addressArray] componentsJoinedByString:@","];

就是这样……