Regex 以Swift发行正则表达式

我正在使用一个用户名正则表达式，其中唯一可以接受的字符是a-z、a-z、0-9和x。用户名的当前最大长度为18个字符，最小长度为1个。我现在的正则表达式如下

让regexCorrectPattern=“[a-zA-Z0-9}{1,18}$”

我有以下问题。在字符串末尾以外的任何位置添加的特殊字符允许正则表达式通过。比如说

乔恩！失败

!！琼帕斯

j！通行证

下面是我用来测试正则表达式的方法以及调用方法。如有任何意见，将不胜感激

正则表达式测试方法

func regexTestString(string: String, withPattern regexPattern: String) -> Bool
{
        // This method is used for all of the methods below.  
        do
        {
            // Create regex and regex range.
            let regex = try NSRegularExpression(pattern: regexPattern, options: .CaseInsensitive)
            let range = NSMakeRange(0, string.characters.count)

            // Test for the number of regex matches.
            let numberOfMatches = regex.numberOfMatchesInString(string, options: [], range: range)

            // Testing Code.
            print(numberOfMatches)

            // Return true if the number of matches is greater than 1 and return false if the number of mathces is 0.
            return (numberOfMatches == 0) ? false : true
        }
        catch
        {
            // Testing Code
            print("There is an error in the SignUpViewController regexTestString() method \(error)")

            // If there is an error return false.
            return false
        }
    }

func usernameTextFieldDidEndEditing(sender: AnyObject)
    {
        let usernameText = self.usernameField.text!.lowercaseString

        let regexCorrectPattern = "[a-zA-Z0-9_]{1,18}$"
        let regexWhitespacePattern = "\\s"
        let regexSpecialCharacterPattern = ".*[^A-Za-z0-9].*"

        if regexTestString(usernameText, withPattern: regexCorrectPattern)
        {
            // The regex has passed hide the regexNotificationView

        }
        else if regexTestString(usernameText, withPattern: regexWhitespacePattern)
        {
            // The username contains whitespace characters.  Alert the user.
        }
        else if regexTestString(usernameText, withPattern: regexSpecialCharacterPattern)
        {
            // The username contains special characters.  Alert the user.
        }
        else if usernameText == ""
        {
            // The usernameField is empty.  Make sure the sign up button is disabled.
        }
        else
        {
            // For some reason the Regex is false.  Disable the sign up button.
        }
    }

调用方法

func regexTestString(string: String, withPattern regexPattern: String) -> Bool
{
        // This method is used for all of the methods below.  
        do
        {
            // Create regex and regex range.
            let regex = try NSRegularExpression(pattern: regexPattern, options: .CaseInsensitive)
            let range = NSMakeRange(0, string.characters.count)

            // Test for the number of regex matches.
            let numberOfMatches = regex.numberOfMatchesInString(string, options: [], range: range)

            // Testing Code.
            print(numberOfMatches)

            // Return true if the number of matches is greater than 1 and return false if the number of mathces is 0.
            return (numberOfMatches == 0) ? false : true
        }
        catch
        {
            // Testing Code
            print("There is an error in the SignUpViewController regexTestString() method \(error)")

            // If there is an error return false.
            return false
        }
    }

func usernameTextFieldDidEndEditing(sender: AnyObject)
    {
        let usernameText = self.usernameField.text!.lowercaseString

        let regexCorrectPattern = "[a-zA-Z0-9_]{1,18}$"
        let regexWhitespacePattern = "\\s"
        let regexSpecialCharacterPattern = ".*[^A-Za-z0-9].*"

        if regexTestString(usernameText, withPattern: regexCorrectPattern)
        {
            // The regex has passed hide the regexNotificationView

        }
        else if regexTestString(usernameText, withPattern: regexWhitespacePattern)
        {
            // The username contains whitespace characters.  Alert the user.
        }
        else if regexTestString(usernameText, withPattern: regexSpecialCharacterPattern)
        {
            // The username contains special characters.  Alert the user.
        }
        else if usernameText == ""
        {
            // The usernameField is empty.  Make sure the sign up button is disabled.
        }
        else
        {
            // For some reason the Regex is false.  Disable the sign up button.
        }
    }

---

您希望整个字符串仅包含指定的字符，因此只需在模式的开头添加

^

：

---

^[a-zA-Z0-9{1,18}$

a-z、a-z、0-9和

如何

！jon应该通过吗？太棒了！这非常有效。谢谢你的帮助。