ios - 如何根据另一个数组中的值向 NSMutableArray 添加索引？

Question

我看过很多关于 NS(可变)数组的问题。我想我没有理解这个概念，或者这些问题似乎不相关。

我想做的是:

传入数组 1:

姓名代码开始时间时间结束等等

传入数组 2

代码序数

我想要的:

序数姓名代码开始时间时间结束等等

这是我目前的代码:

int i=0;
for (i=0; i < stationListArray.count; i++) {
    NSString *slCodeString = [stationListArray[i] valueForKey:@"Code"];
    NSLog(@"slCodeString: %@", slCodeString);
    int j=0;
    for (j=0; j< lineSequenceArray.count; j++) {
        NSString *lsCodeString = [lineSequenceArray[j]valueForKey:@"StationCode"];
        NSLog(@"lsCodeString: %@", lsCodeString);
        if ([slCodeString isEqualToString:lsCodeString]) {
            NSLog(@"match");
            NSString *ordinalString = [lineSequenceArray[j] valueForKey:@"SeqNum"];
            NSLog(@"ordinalString: %@", ordinalString);
            [stationListArray[i] addObject:ordinalString]; <------
        }
    }
}

我正在记录值，它们正确返回。编译器不喜欢最后一条语句。我收到此错误:

[__NSCFDictionary addObject:]: unrecognized selector sent to instance 0x7f9f63e13c30
 *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFDictionary addObject:]: unrecognized selector sent to instance 0x7f9f63e13c30'

这是 StationListArray 的摘录:

(
        {
        Address =         {
            City = Greenbelt;
            State = MD;
            Street = ".....";
            Zip = 20740;
        };
        Code = E10;
        Lat = "39.0111458605";
        Lon = "-76.9110575731";
        Name = Greenbelt;
    }   
)

Answer 1

        NSString *ordinalString = [lineSequenceArray[j] valueForKey:@"SeqNum"]; //Is NSString
        [stationListArray[i] addObject:ordinalString];//<----- trying to call addObject method of NSMutableArray on NSDictionary -> Not GOOD 

当你执行 [stationListArray[i] 时，你会得到 NSDictionary(通常它返回一个 NSObject，它位于给定索引处的 NSArray 内，在您的例子中是 NSDictionary)。

因此，为了完成您想要的操作:您应该制作一个 NSMutableDictionary 实例(在这种情况下，它应该是 stationListArray[i] 中的 mutableCopy 的 NSObject 即 NSDictionary，当您执行 mutableCopy 时，它会复制整个 NSDictionary 并使它可变)对其进行更改，然后将其分配给 stationListArray[i]

例如:

NSMutableDictionary * tempDict = [[stationArray objectAtIndex:i]mutableCopy];//Create a mutable copy of the `NSDictionary` that is inside the `NSArray`
[[tempDict setObject:ordinalString forKey:@"Ordinal"]; //In this line you are adding the Ordinal `NSString` in to the tempDict `NSMutableDictionary` so now you have the desired `NSMutableDictionary`. You can change the key to whatever you wish.
[stationArray replaceObjectAtIndex:i withObject:[tempDict copy]];//Swap the original(old NSDictionary) with the new updated `NSMutableDictionary` I used the copy method in order to replace it with the IMMUTABLE `NSDictionary`