ios - 使用*作为Realm中 'LIKE'的常规字符过滤对象

Question

我尝试查找包含带有通配符的子字符串的字符串。在下面的示例中，字符串应确认模式(任何符号 '*' 任何符号 'p' 任何符号) 。我尝试使用此代码从 Realm 中搜索对象

class ServiceMessage: Object {
  @objc dynamic var desc = ""
}

let realm = try! Realm()

let dataSource = [
    "Domain CheckService",
    "IMEI check",
    "Compliant about service provider",
    "Compliant about TRA",
    "Enquires",
    "Suggestion",
    "SMS* S[pam",
    "Poor Coverage",
    "Pure *Signal",
    "Help Salim"
]

for text in dataSource {
    let sm = ServiceMessage()
    sm.desc = text;
    try! realm.write {
        realm.add(sm)
    }
}


let searchString = "*\\**p*"
let predicate = NSPredicate(format: "SELF.desc LIKE[c] %@", searchString)
let errors = realm.objects(ServiceMessage.self).filter(predicate)

我什么也没得到。如果我尝试使用此谓词过滤简单的字符串数组，一切都会正常工作。有人知道这个问题的解决方案吗？我尝试在 LIKE 之后添加 [w]，但这对我没有帮助。

Answer 1

这里的主要问题是您不能在 Realm 中使用正则表达式作为谓词，我们可以在此处阅读 https://github.com/realm/realm-cocoa/issues/2629正确的方法应该是

let realmInstance = try? Realm()
let expresion = ".*\\*.*p.*"
let predicate = NSPredicate(format: "SELF.name MATCHES %@", expresion)
self.realmArrayDogs = realmInstance?.objects(Dog.self).filter(predicate)

但这会因以下错误而崩溃

Terminating app due to uncaught exception 'Invalid operator type', reason: 'Operator 'MATCHES' not supported for string type'

这是使用 stringArray 进行相同操作的示例

let array = ["D*usadpdasd","probando","asdasd*ffffpppp"]
    do{
        let expresion = ".*\\*.*p.*"
        let predicate = NSPredicate(format: "SELF MATCHES %@",expresion)
        let resultArray = array.filter({predicate.evaluate(with: $0)})
        debugPrint(resultArray)
    }
    catch
    {

    }

作为解决方法，您可以将结果从 Realm 转换为数组，然后使用谓词进行过滤

这有效!

let realmInstance = try? Realm()
let expresion = ".*\\*.*p.*"
let predicate = NSPredicate(format: "SELF.name MATCHES %@", expresion)
let arrayOfDogsResult = realmInstance?.objects(Dog.self)
let filteredArray = Array(arrayOfDogsResult!).filter({predicate.evaluate(with: $0)})
debugPrint(filteredArray)