ios - 当 NSPredicate 匹配带有括号的字符串时崩溃

Question

当我尝试使用包含括号的字符串运行 NSPredicate 时，我的应用程序始终崩溃。下面是示例代码:

NSString *myString = @"test)";
NSPredicate *defaultPredicate = [NSPredicate predicateWithFormat:@"title MATCHES[cd] %@", myString];

这是生成的崩溃日志:

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Can't do regex matching, reason: Can't open pattern U_REGEX_MISMATCHED_PAREN (string test, pattern test), case 1, canon 2)

在我的用例中，人们不应该使用括号搜索字符串，因此我可以通过执行类似于下面的代码的操作来清理字符串，但这并不优雅。

myString = [[myString stringByReplacingOccurrencesOfString:@"(" withString:@""] stringByReplacingOccurrencesOfString:@")" withString:@""];

任何帮助或线索将不胜感激。谢谢!

Answer 1

MATCHES 用于正则表达式比较。您的表达式被视为正则表达式。如果您的表达式不是有效的正则表达式，它将失败。因此，如果您使用 MATCHES，您通常不希望未经过滤的用户输入，因为每次使用不完整的正则表达式时都会失败。

也许是另一个 String Comparison会更好。

String comparisons are, by default, case and diacritic sensitive. You can modify an operator using the key characters c and d within square braces to specify case and diacritic insensitivity respectively, for example firstName BEGINSWITH[cd] $FIRST_NAME.

BEGINSWITH
The left-hand expression begins with the right-hand expression.

CONTAINS The left-hand expression contains the right-hand expression.

ENDSWITH
The left-hand expression ends with the right-hand expression.

LIKE
The left hand expression equals the right-hand expression: ? and * are allowed as wildcard characters, where ? matches 1 character and * matches 0 or more characters.

MATCHES
The left hand expression equals the right hand expression using a regex-style comparison according to ICU v3 (for more details see the ICU User Guide for Regular Expressions).