Question

我知道有很多问题像我一样，但仍然无法让它发挥作用？

我有一个NSMutableDictionary，我甚至没有枚举我只是想改变它的值，但我得到错误信息：

发送到不可变对象的变异对象

这是代码.. 我将字典作为参数，我们称之为myDictionary

NSString *stringToUpdate  = @"SomeString";
[myDictionary setObject:stringToUpdate forKey:@"time"];

这是我得到我的词典的地方 GameInfo.m

     @class GameInfo;

@interface GetData : NSObject

@property (nonatomic, strong) NSMutableArray *gamesInfoArray;
@property (nonatomic, strong) NSMutableDictionary *jsonDict;


-(void) fetchData;
-(NSMutableArray *) getAllGames;
-(NSMutableArray *) getAllLiveGames;
- (NSMutableDictionary *) getGameInfoObject: (NSString *) gameObjectID;

-(void) postEventInfo: (NSDictionary *) eventInfoObject;

@end

GameInfo.h

  -(void) fetchData{

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    [request setHTTPMethod:@"GET"];
    [request setURL:[NSURL URLWithString:url]];

    NSError *error = [[NSError alloc] init];
    NSHTTPURLResponse *responseCode = nil;

    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&responseCode error:&error];

    if([responseCode statusCode] != 200){
        NSLog(@"Error getting %@, HTTP status code %li", url, (long)[responseCode statusCode]);
    }

    jsonDict = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];

}

- (NSMutableDictionary *) getGameInfoObject: (NSString *) gameObjectID {

[self fetchData];

DataParser *dataParserObject = [[DataParser alloc] init];

return [dataParserObject sendBackDetailObject:jsonDict andGameID:gameObjectID]; 
// and this is where i send this NSMutableDictionary to the problem described on the top


}

Answer 1

默认情况下，

+[NSJSONSerialization JSONObjectWithData:options:error:]将返回NSArray NSDictionary个不可变的内容。

您需要获取此副本并将其分配给您的实例变量

NSError *JSONError = nil;

jsonDict = [[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&JSONError] mutableCopy];

if (!jsonDict) {
  NSLog(@"Failed to parse JSON: %@", JSONError.localizedDescription);
}

或者为JSON解析方法提供NSJSONReadingMutableContainers选项

NSError *JSONError = nil;

jsonDict = [NSJSONSerialization JSONObjectWithData:data 
                                           options:NSJSONReadingMutableContainers
                                             error:&JSONError];

if (!jsonDict) {
  NSLog(@"Failed to parse JSON: %@", JSONError.localizedDescription);
}

无法更新NSMutableDictionary中的值

1 个答案: