Question

我想添加一个不同的Dictionary作为另一个键字典的值，但是在我的循环中，我发现我的所有字典键都添加了相同的值。这是我的代码：

for (MyObject *message in messages) {
        int value = [key intValue] +1;

[mess setObject:message.body forKey:@"msg"];
        [mess setObject:message.bareJidStr forKey:@"sender"];
        [mess setObject:[element attributeStringValueForName:@"to"] forKey:@"reciever"];
        [mess setObject:message.timestamp forKey:@"date"];
        [[self messagesHistory] setObject:mess forKey:[NSString stringWithFormat:@"%d",value]];
}

有些东西不能正常工作，但我可以找出原因！谢谢你的帮助。

Answer 1

因为您要添加相同的字典

你必须在循环之前有这一行

NSMutableDictionary *mess = [NSMutableDictionary dictionary];

因此您只创建一个字典并将其用作所有键的值

你需要在循环中移动这一行

for (MyObject *message in messages) {
        // create a new dictionary for each value
        NSMutableDictionary *mess = [NSMutableDictionary dictionary];
        int value = [key intValue] +1;

        [mess setObject:message.body forKey:@"msg"];
        [mess setObject:message.bareJidStr forKey:@"sender"];
        [mess setObject:[element attributeStringValueForName:@"to"] forKey:@"reciever"];
        [mess setObject:message.timestamp forKey:@"date"];
        [[self messagesHistory] setObject:mess forKey:[NSString stringWithFormat:@"%d",value]];
}

Answer 2

在循环中创建一个“mess”对象，否则所有值都使用相同的“mess”对象。

for (MyObject *message in messages) 
{
    int value = [key intValue] +1;

    mess = [NSMutableDictionary new];

    [mess setObject:message.body forKey:@"msg"];
        [mess setObject:message.bareJidStr forKey:@"sender"];
        [mess setObject:[element attributeStringValueForName:@"to"] forKey:@"reciever"];
        [mess setObject:message.timestamp forKey:@"date"];
        [[self messagesHistory] setObject:mess forKey:[NSString stringWithFormat:@"%d",value]];
}

添加NSDictionary作为NSDictionary键的值

2 个答案: