ios - 替换 NSPredicate 中字符串中的内容

Question

我正在尝试替换数组中的文本，由于某种原因，尽管 Xcode 没有发出行警报，但代码无法正常工作，这会导致其崩溃。

即“名字，2013”​​

剥离“，2013”​​

结果

“姓名”

我做错了什么，我一生都无法解决这个问题，并且迫切需要帮助？

有问题的具体行是“case ITSectionTypeAuthor:”

- (void)setUpDataByType:(ITSectionType) type andFilter:(NSString *)filter {
    self.type = type;
    self.filter = (filter)? filter : @"";
    [self.sections removeAllObjects];
    NSPredicate *predicate = nil;
    NSString *descriptorKey = @"genus";
    NSArray *rowData = [[ITData sharedObject] animals]; //coming form singleton

    //generate predicate

    switch (self.type) {

        case ITSectionTypeAuthor:
            predicate = [NSPredicate predicateWithFormat:@"describer componentsSeparatedByString:@", "] objectAtIndex:0] LIKE %@", filter];
            break;

        default:
            predicate = nil;
            break;
 }

Answer 1

我认为问题出在这一行:

predicate = [NSPredicate predicateWithFormat:@"describer componentsSeparatedByString:@", "] objectAtIndex:0] LIKE %@", filter];

您正在创建一个 Objective-C 字符串:

@"describer componentsSeparatedByString:@"

然后是 C 字符串:

"] objectAtIndex:0] LIKE %@"

这不对吧？我想你想要:

predicate = [NSPredicate predicateWithFormat:@"describer LIKE %@", [[filter componentsSeparatedByString:@", "] objectAtIndex:0]];