使用NSPredicate与一组答案 [英] using NSPredicate with a set of answers

问题描述

我有一组包含personIDs的字符串，我有一个NSFetchedResults的人managedObjects与唯一的strPersonIDs。我试图创建一个NSPredicate，但它失败。任何帮助，这将非常感谢。我对NSPredicate有点陌生，所以要亲切。

I have a set of strings containing personIDs and I have a NSFetchedResults of people managedObjects with unique strPersonIDs. I tried to create an NSPredicate but it fails. Any help with this would be greatly appreciated. I'm a bit new to NSPredicate so be kind.

NSSet *zipSet = [NSSet setWithSet:[self getziplist:searchText]];
searchString = [NSString stringWithFormat:@"(strPersonID IN %@)",zipSet];
NSPredicate *searchPersonPredicate = [NSPredicate predicateWithFormat:searchString];

运行时错误消息是：由于未捕获异常而终止应用程序NSInvalidArgumentException，原因：无法解析格式字符串（strPersonID IN {（
300040，
300082，
412218
）}）'

The runtime error message is: Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unable to parse the format string "(strPersonID IN {( 300040, 300082, 412218 )})"'

推荐答案

不要在字符串中插入 zipSet ，将其插入谓词：

Don't interpolate zipSet into the string, interpolate it into the predicate:

NSSet *zipSet = [NSSet setWithSet:[self getziplist:searchText]];
NSPredicate *searchPersonPredicate = [NSPredicate predicateWithFormat:@"strPersonID IN %@",zipSet];

如果将NSSet内插到字符串，它将不具有正确的格式（NSString uses -description ，它使用旧的NextStep 属性列表格式）。

If you interpolate the NSSet into a string, it won't have the correct format (NSString uses -description, which uses the old NextStep property list format).

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