檢查密碼包含字母數字和特殊字符

Question

如何檢查字符串passwordText是否至少包含

• 1個字母字符
• 1個號碼
• 1個特殊字符（符號）

Answer 1

嘗試這個：

bool result =
   passwordText.Any(c => char.IsLetter(c)) &&
   passwordText.Any(c => char.IsDigit(c)) &&
   passwordText.Any(c => char.IsSymbol(c));

雖然您可能希望通過“字母字符”，“數字”和“符號”更具體地說明您的意思，因為這些術語對不同的人意味着不同的東西，並且您不確定這些術語的定義是否符合定義框架使用。

我猜你用字母表示“az”或“A-Z”，用數字表示“0-9”，用符號表示任何其他可打印的ASCII字符。 如果是這樣，試試這個：

static bool IsLetter(char c)
{
    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
}

static bool IsDigit(char c)
{
    return c >= '0' && c <= '9';
}

static bool IsSymbol(char c)
{
    return c > 32 && c < 127 && !IsDigit(c) && !IsLetter(c);
}

static bool IsValidPassword(string password)
{
    return
       password.Any(c => IsLetter(c)) &&
       password.Any(c => IsDigit(c)) &&
       password.Any(c => IsSymbol(c));
}

如果實際上你的意思是其他東西，那么相應地調整上述方法。

Answer 2

使用RegEx將是最靈活的。 您始終可以將其存儲在資源文件中，並在不進行代碼更改的情況下進行更改。

有關密碼示例，請參閱以下內容;

http://regexlib.com/Search.aspx?k=password

Answer 3

您可以使用String.IndexOfAny()來確定字符串中是否存在指定字符數組中的至少一個字符。

Answer 4

strPassword.IndexOfAny(new char['!','@','#','$','%','^','&','*','(',')']);

您可以使用您正在尋找的字符/符號數組來運行它。 如果它返回大於-1的任何值，那么你就得到了一個匹配。 數字也可以這樣做。

這將允許您准確定義您要查找的內容，並且如果您願意，可以輕松地排除某些字符。

Answer 5

這很簡單;

Regex sampleRegex = new Regex(@"(?!^[0-9]*$)(?!^[a-zA-Z]*$)^([a-zA-Z0-9]{2,})$");
boolean isStrongPassword= sampleRegex.IsMatch(givenPassword);

Answer 6

對於非常簡單的事情，我從之前使用的程序中獲取了這個。

            //password rules 
            int minUpper = 3;
            int minLower = 3;
            int minLength = 8;
            int maxLength = 12;
            string allowedSpecials = "@#/.!')";

            //entered password
            string enteredPassword = "TEStpass123@";

            //get individual characters
            char[] characters = enteredPassword.ToCharArray();

            //checking variables

            int upper = 0;
            int lower = 0;
            int character = 0;
            int number = 0;
            int length = enteredPassword.Length;
            int illegalCharacters = 0;


            //check the entered password
            foreach (char enteredCharacters in characters)
            {
                if (char.IsUpper(enteredCharacters))
                {
                    upper = upper + 1;
                }
                else if (char.IsLower(enteredCharacters))
                {
                    lower = lower + 1;
                }
                else if (char.IsNumber(enteredCharacters))
                {
                    number = number + 1;
                }
                else if (allowedSpecials.Contains(enteredCharacters.ToString()))
                {
                    character = character + 1;
                }
                else
                {
                    illegalCharacters = illegalCharacters + 1;
                }

                // MessageBox.Show(chars.ToString());
            }

            if (upper < minUpper || lower < minLower || length < minLength || length > maxLength || illegalCharacters >=1)
            {
                MessageBox.Show("Something's not right, your password does not meet the minimum security criteria");
            }
            else
            {
                //code to proceed this step
            }

Answer 7

這應該符合您的所有要求。 它不使用正則表達式。

private bool TestPassword(string passwordText, int minimumLength=5, int maximumLength=12,int minimumNumbers=1, int minimumSpecialCharacters=1) {
    //Assumes that special characters are anything except upper and lower case letters and digits
    //Assumes that ASCII is being used (not suitable for many languages)

    int letters = 0;
    int digits = 0;
    int specialCharacters = 0;

    //Make sure there are enough total characters
    if (passwordText.Length < minimumLength)
    {
        ShowError("You must have at least " + minimumLength + " characters in your password.");
        return false;
    }
    //Make sure there are enough total characters
    if (passwordText.Length > maximumLength)
    {
        ShowError("You must have no more than " + maximumLength + " characters in your password.");
        return false;
    }

    foreach (var ch in passwordText)
    {
        if (char.IsLetter(ch)) letters++; //increment letters
        if (char.IsDigit(ch)) digits++; //increment digits

        //Test for only letters and numbers...
        if (!((ch > 47 && ch < 58) || (ch > 64 && ch < 91) || (ch > 96 && ch < 123)))
        {
            specialCharacters++;
        }
    }

    //Make sure there are enough digits
    if (digits < minimumNumbers)
    {
        ShowError("You must have at least " + minimumNumbers + " numbers in your password.");
        return false;
    }
    //Make sure there are enough special characters -- !(a-zA-Z0-9)
    if (specialCharacters < minimumSpecialCharacters)
    {
        ShowError("You must have at least " + minimumSpecialCharacters + " special characters (like @,$,%,#) in your password.");
        return false;
    }

    return true;        
}

private void ShowError(string errorMessage) {
    Console.WriteLine(errorMessage);
}

這是如何調用它的示例：

private void txtPassword_TextChanged(object sender, EventArgs e)
{
    bool temp = TestPassword(txtPassword.Text, 6, 10, 2, 1);
}

這不測試大寫和小寫字母的混合，這可能是優選的。 為此，只需將char條件中斷(ch > 96 && ch < 123)為小寫字母組(ch > 64 && ch < 91)為大寫。

正則表達式更短更簡單（適合那些使用它的人）並且在線有很多例子，但這種方法更適合為用戶定制反饋。