Question

我想为某个键设置一个对象的值，但是我得到了这个奇怪的错误。我也尝试使用setValue而不是setObject，而routenArray2也得到了密钥。

NSMutableArray *routenArray = [[NSMutableArray alloc] init];
NSMutableArray *routenArray2 = [[NSMutableArray alloc] init];

NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithObjectsAndKeys:
abfahrt,@"Abfahrt", ankunft, @"Ankunft", dauer, @"Dauer", route, @"Route", kennung, @"Kennung", nil];

[routenArray addObject:dict];

for (int j = 0; j < routenArray.count; j++) {

    NSNumber *lNumber = [indexArray objectAtIndex:j];
    int l = [lNumber intValue];

    if (l == i) {
          [routenArray2 addObject:[[routenArray objectAtIndex:j] copy]];
    }
}

NSString *kennungString = [NSString stringWithFormat:@"%d", k];

for (int i = 0; i < routenArray2.count; i++) {
      [[routenArray2 objectAtIndex:i] setObject:kennungString forKey:@"Kennung"]; //this line is the problem
}

Answer 1

使用

[routenArray2 addObject:[[routenArray objectAtIndex:j] mutableCopy]];

而不是

[routenArray2 addObject:[[routenArray objectAtIndex:j] copy]];

copy返回NSDictionary，您需要mutableCopy才能返回NSMutableDictionary。

Answer 2

试试这个：

NSMutableDictionary *newDict = (NSMutableDictionary *)[routenArray2 objectAtIndex:i];
[newDict setObject:kennungString forKey:@"Kennung"];

Answer 3

在分配值

时尝试进行类型转换

[(NSMutableDictionary *)[routenArray2 objectAtIndex:i] setObject:kennungString forKey:@"Kennung"];

XCode：＆＃39;无法识别的选择器发送到实例＆＃39;

3 个答案: