从NSArray Objective-C创建NSMutableArray

Question

我有一个NSArray，它给了我以下数据：

01/14/2013 13:28:06.559 IUser Reader [71164: c07] (
         {
         "id_acompanhante" = "";
         "id_evento" = 34;
         "user_id" = 1;
         "inserido_por" = "Himself";
         name = iUser;
         status = done;
         type = User;
     }
         {
         "id_acompanhante" = 1;
         "id_evento" = 34;
         "user_id" = 1;
         "inserido_por" = iUser;
         name = "Mayara Roca";
         status = naofeito;
         type = companion;
     }
)

如何将此数据播放到NSMutableArray并在每个项目中添加另一个字段。 例：

  {
     "id_acompanhante" = "";
     "id_evento" = 34;
     "user_id" = 1;
     "inserido_por" = "Himself";
     name = IUser;
     status = done;
     type = User;
     tag = 2;
 }

我又增加了一个字段“TAG”。

我该怎么做呢？

Answer 1

NSMutableArray *mutableArray = [NSMutableArray array];

for (NSDictionary *dictionary in yourArray) {
    NSMutableDictionary *mutDictionary = [dictionary mutableCopy];

    [mutDictionary setObject:[NSNumber numberWithInt:2] forKey:@"tag"];

    [mutableArray addObject:mutDictionary];
}

这是你怎么做的。 使数组可变不允许您更改其中的字典的内容。 您需要提取每个字典并使其变为可变，然后将其存储回数组中。

Answer 2

简单

NSMutableArray *mArray = [NSMutableArray arrayWithArray:yourArray]
[mArray addObject:yourObject];

Answer 3

它就像在你的数组上调用mutableCopy一样简单：

NSArray * myArray = @[@"one", @"two", @"three"];
NSMutableArray * myMut = [myArray mutableCopy];
NSLog(@"My Mut = %@", myMut);

希望有所帮助！

更新此处是一个迭代原始数组的示例，将项目转换为可变字典并插入新属性。 然后抛出原始数组并使用myMut版本。

NSArray * myArray = @[@{@"key1":@"value1"}, @{@"key2":@"value2"}];
NSMutableArray * myMut = [[NSMutableArray alloc] init];
for (NSDictionary * dict in myArray) {
    NSMutableDictionary * mutDict = [dict mutableCopy];
    [mutDict setObject:@"2" forKey:@"tag"]; // Add new properties
    [myMut addObject:mutDict];
}

Answer 4

试试这个

NSMutableArray *aMutableArray = [NSMutableArray arrayWithArray:anArray];

Answer 5

据我所知，你不需要一个可变数组，但你需要将数组中的NSDictionaries转换为可变的。 其他人也回答了这个问题。

但我想展示一个漂亮的技巧，你可以设置如何在线添加一个键/值对所有可变字典。 我使用更简单的数据，因此更容易看到，会发生什么。

//just an example array of mutable Dictionary
NSMutableArray *array = [NSMutableArray array];
[array addObject:[NSMutableDictionary dictionaryWithObject:@"one" forKey:@(1)]];
[array addObject:[NSMutableDictionary dictionaryWithObject:@"two" forKey:@(2)]];
[array addObject:[NSMutableDictionary dictionaryWithObject:@"three" forKey:@(3)]];

// and here is the trick
[array setValue:@"10" forKey:@"tag"];

该数组现在包含

(
{
    tag = 10;
    1 = one;
},
{
    tag = 10;
    2 = two;
},
{
    3 = three;
    tag = 10;
}
)

来自NSArray文档

setValue:forKey:
使用指定的值和键在每个数组的项上调用setValue：forKey :.

 - (void)setValue:(id)value forKey:(NSString *)key 

Answer 6

NSArray *theOldArray; // your old array
NSMutableArray *theMutableAry = [NSMutableArray array];
for (NSDictionary *dicItem in theOldArray)
{
    NSMutableDictionary *dicWithOneMoreField = [NSMutableDictionary dictionaryWithDictionary:dicItem];
    [dicWithOneMoreField setValue:@"your value for tag" forKey:@"tag"];
    [theMutableAry addObject:dicWithOneMoreField];
}

或者尝试另一种方式

NSData* archivedData = [NSKeyedArchiver archivedDataWithRootObject:theOldArray];
NSMutableArray *mutableArray = [NSKeyedUnarchiver unarchiveObjectWithData:archivedData];
for (NSDictionary *dicItem in mutableArray)
{
    [dicItem setValue:@"your value for tag" forKey:@"tag"];
}