ios - 根据字典键过滤 NSDictionary 的 NSArray

Question

我有一个 NSArray 的 NSDictionary，我想从中过滤掉一个特定的字典。使用下面的代码，我得到了 nil matchedDicts。我做错了什么吗？

NSPredicate *p = [NSPredicate predicateWithFormat:@"locationID = %@", @"949"];
NSArray *matchedDicts = [aLocationsList filteredArrayUsingPredicate:p];

{
    locationID = 2023;
    locationName = "Customer";
    sortOrder = 0;
},
{
    locationID = 2024;
    locationName = "My Loc";
    sortOrder = 1;
},
{
    locationID = 949;
    locationName = "His Loc";
    sortOrder = 2;
}
)

Answer 1

您可以使用 block 格式来代替:

-(NSArray*)filterArrayOfDictionaries:(NSArray*)arr
{
    NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(NSDictionary *dict, NSDictionary *bindings) {
        NSNumber *locationID = dict[@"locationID"];

        if([locationID intValue]==949)
        {
            return YES;
        }
        return NO;
    }];

    return [arr filteredArrayUsingPredicate:predicate];
}