__NSDictionaryI setObject：forKey：崩溃

Question

问题是我正在改变NSDictionary，但即使在获得mutableCopy后，该应用也会崩溃。

以下是方法，用于复制：

+ (NSMutableDictionary *)updateQuery:(NSMutableDictionary *)currentQuery toSearchAfterAccountPaginationSequence:(NSString *)accountPaginationSequence {

    //try1
    NSMutableDictionary *mutableQuery = [currentQuery mutableCopy];

    //try2 
    NSMutableDictionary *mutableQuery2=[NSMutableDictionary dictionaryWithDictionary:currentQuery];

    //crashes on this line
    mutableQuery[@"where"][@"account_pagination_sequence"] = @{ @"lt" : accountPaginationSequence };

    return mutableQuery;
}

错误日志（应用程序在有限数量的设备上崩溃）

[__NSDictionaryI setObject:forKey:]: unrecognized selector sent to instance

Answer 1

我认为这是你想要实现的目标

for(int i = 0; i< n; i++){
   cin >> a[i];
}

编辑： 在Objective-C中调用对象上的mutableCopy不是递归的。你也需要在嵌套对象中调用mutableCopy。