NSMutableArray(iOS)中的NSDictionary

时间:2013-03-22 16:01:44

标签: ios objective-c nsmutablearray nsdictionary

我需要以下结果:

(

    "some_key" = {
        "another_key" = "another_value";
    };

);

为了做到这一点,我有这个代码,但它不起作用:

NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys:@"another_value", @"another_key", nil];
NSMutableArray *array = [[NSMutableArray alloc] init];
[array setValue:dictionary forKey:@"some_key"];

任何想法?谢谢!

5 个答案:

答案 0 :(得分:16)

您的错误在这里:

NSMutableArray *array = [[NSMutableArray alloc] init];
[array setValue:dictionary forKey:@"some_key"];

------------ ^^^^^

您将此设置为数组。

试试这个:

NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys:@"another_value", @"another_key", nil];
NSDictionary *outDict=[[NSDictionary alloc]initWithObjectsAndKeys:dictionary,@"some_key", nil];
NSMutableArray *array = [[NSMutableArray alloc] initWithObjects:outDict, nil];

在新文字中:

NSDictionary *d=@{@"another_key":@"another_value"};
NSDictionary *c=@{@"some_key":d};
NSArray *array=@[c];

或嵌套创作:

NSArray *array=@[@{@"some_key":@{@"another_key":@"another_value"}}];

答案 1 :(得分:4)

通常只需在末尾添加对象即可构建NSMutableArray。方法是addObject:

NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys:@"another_value", @"another_key", nil];
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:dictionary];

另一方面,如果你想通过一个键来解决字典(@" some_key"),那么你也需要外容器作为字典:

NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys:@"another_value", @"another_key", nil];
NSMutableDictionary *outerDict = [NSMutableDictionary dictionary];
[outerDict setObject:dictionary forKey:@"some_key"];

答案 2 :(得分:2)

来自文档

  

setValue:forKey: - 设置a指定的接收者的属性   给定给定值的关键。

NSKeyValueCoding协议。您正在使用错误的方法将对象添加到数组中,NSArray是有序集合,而不是字典。做你需要的最简单的方法是:

NSDictionary* dic = @{@"some_key": @{@"another_key": @"another_value"}};

如您所见,输出为NSDictionary而不是NSArray

答案 3 :(得分:2)

数组不使用setValue:forKey:(也不是setObject:forKey:),数组不像字典那样关联。

setValue:forKey:是KVC(键值编码)。

你想要一个字典词典数组(下面是伪plist形式)

<array>
  <dict>
    <key>someKey</key>
    <dict>
      <key>someOtherKey</key>
      <string>someValue</string>
    </dict>
  </dict>
  <dict>
    <key>someKey</key>
    <dict>
      <key>someOtherKey</key>
      <string>someValue</string>
    </dict>
  </dict>
  <dict>
    <key>someKey</key>
    <dict>
      <key>someOtherKey</key>
      <string>someValue</string>
    </dict>
  </dict>
  <dict>
    <key>someKey</key>
    <dict>
      <key>someOtherKey</key>
      <string>someValue</string>
    </dict>
  </dict>
</array>

`

答案 4 :(得分:2)

我认为你正在寻找这种结构

NSDictionary *anotherKeyValueDictionary = 
 [[NSDictionary alloc] initWithObjectsAndKeys:@"another_value", 
                                              @"another_key", nil];
NSDictionary *someKeyValueDictionary = 
 [[NSDictionary alloc] initWithObjectsAndKeys:@"anotherKeyValueDictionary", 
                                              @"some_key", nil];
NSMutableArray *array = [[NSMutableArray alloc] init];
[array addObject:someKeyValueDictionary];