iphone - 使用 NSPredicate 过滤 NSArray/NSDictionary

Question

我一直在尝试使用 NSPredicate 来过滤这个数组(其中充满了 NSDictionaries)...

我有非常少量的代码无法正常工作...

下面的代码应该将 label.text 更改为 AmyBurnett34，但它没有...

NSPredicate *pred = [NSPredicate predicateWithFormat:@"id = %@", [[mightyPlistDict objectForKey:@"pushesArr"] objectAtIndex:indexPath.row]];

    NSLog(@"%@",pred);

    label.text = [[[twitterInfo filteredArrayUsingPredicate:pred] lastObject] objectForKey:@"screen_name"];
    NSLog(@"%@",twitterInfo);

这就是得到 NSLoged 的​​...

2012-08-05 11:39:45.929 VideoPush[1711:707] id == "101323790"
2012-08-05 11:39:45.931 VideoPush[1711:707] (
        {
        id = 101323790;
        "screen_name" = AmyBurnett34;
    },
        {
        id = 25073877;
        "screen_name" = realDonaldTrump;
    },
        {
        id = 159462573;
        "screen_name" = ecomagination;
    },
        {
        id = 285234969;
        "screen_name" = "UCB_Properties";
    },
        {
        id = 14315150;
        "screen_name" = MichaelHyatt;
    }
)

如果您还使用 NSLog 这个...数组是空的...

NSLog(%@,[twitterInfo filteredArrayUsingPredicate:pred]);

Answer 1

问题是您的谓词正在使用与字符串的比较，而您的内容正在使用数字。试试这个:

NSNumber *idNumber = [NSNumber numberWithLongLong:[[[mightyPlistDict objectForKey:@"pushesArr"] objectAtIndex:indexPath.row] longLongValue]];
NSPredicate *pred = [NSPredicate predicateWithFormat:@"id = %@", idNumber];