NSArray objectAtIndex 不起作用。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:@", "];
    }       
}

地址是一个 NSArray，它保存一个地址，

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;
    }
)

我正在尝试遍历该数组并创建一个 CSV 字符串，因此它看起来像

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

但是，我一直在

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

收到的消息已

 *** -[NSCFDictionary stringByAppendingString:]: unrecognized selector sent to instance 0x1c2f10

更新时崩溃： 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

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

要以数组形式获取字典的值，您可以使用，

[theDictionary allValues]

但没有顺序保证。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

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< /a>.您将需要使用 [dictionary objectForKey:'City'] 访问其成员，

因此，更新后的代码应为：

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

如果您可以更改您的 addressArray 方法以实际返回一个数组而不是字典，那么您可以这样做：

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

就是这样......