Ios Swift NSPredicate评估失败

我对使用Regex和NSPredicates不太熟悉。我正在尝试将以下目标代码转换为swift，但失败，出现以下错误：

“NSInvalidArgumentException”，原因：“无法在上进行正则表达式匹配。” 对象自匹配“++（[A-Za-z0-9-]+\）+[A-Za-z]{2}[A-Za-z]*”

目标C代码：

- (BOOL)validateEmailWithString:(NSString*)userEmail
{
    BOOL stricterFilter = NO;
    NSString *stricterFilterString = @"[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}";
    NSString *laxString = @".+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2}[A-Za-z]*";
    NSString *emailRegex = stricterFilter ? stricterFilterString : laxString;
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
    return [emailTest evaluateWithObject:userEmail];
}

等效Swift代码

func validateEmail(withString userEmail: String) -> Bool {
        let stricterFilter: Bool = false
        let stricterFilterString: String = "[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}"
        let laxString: String = ".+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2}[A-Za-z]*"
        let emailRegex: String = stricterFilter ? stricterFilterString : laxString
        let emailTest = NSPredicate(format: "SELF MATCHES %@", emailRegex)
        return emailTest.evaluate(with: emailTest)
    }

此行出现异常：

return emailTest.evaluate(with: emailTest)

---

目标C代码工作正常，但在swift中应用程序崩溃。有人能帮我吗？

请用这条线测试一下

let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"

let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
return emailTest.evaluateWithObject(userEmail)

试试这个

func validateEmailWithString(checkString : String) -> Bool {

    let emailFormat = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"
    let emailPredicate = NSPredicate(format:"SELF MATCHES %@", emailFormat)
    return emailPredicate.evaluate(with: checkString)
}

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评估。。。用户电子邮件与评估。。。emailTest

您可以在此处找到答案Cheers@vadian谢谢你指出这个问题。我的错！