Question

NSString *downloadedItemIDString = [dict objectForKey:@"id"];
NSLog(@"downloadedItemIDString = %@", downloadedItemIDString);

if([storedRecordsDict objectForKey:downloadedItemIDString] != nil)
      NSLog(@"1) Item WITH ID %@ EXISTS!", downloadedItemIDString);
if([storedRecordsDict objectForKey:@"6226691114401792"] != nil)
      NSLog(@"2) Item WITH ID 6226691114401792 EXISTS!");

记录：

2014-04-15 20：51：37.336 AppDemo [2201：60b] downloadedItemIDString = 6226691114401792
2014-04-15 20：51：37.337 AppDemo [2201：60b] 2）项目ID为6226691114401792 EXISTS！

我是Obj C的新手，我一直试图解决这个问题几个小时..请帮助我理解为什么在提供NSString作为密钥时它找不到对象？

Answer 1

NSString *downloadedItemIDString = [dict objectForKey:@"id"];
NSLog(@"downloadedItemIDString = %@", downloadedItemIDString);
if([downloadedItemIDString isEqualToString:@"6226691114401792"])
{
    if([storedRecordsDict objectForKey:downloadedItemIDString] != nil)
        NSLog(@"1) Item WITH ID %@ EXISTS!", downloadedItemIDString);
if([storedRecordsDict objectForKey:@"6226691114401792"] != nil)
    NSLog(@"2) Item WITH ID 6226691114401792 EXISTS!");
}

首先检查你的downloadedItemIDString是否等于@“6226691114401792”，然后检查条件是否都会执行。

NSDictionary使用NSString键的奇怪行为

1 个答案: