使用RegEx进行文本框验证

Question

I want to validate textbox within my c# form so I made this method to do check below

1. Only number are allowed.

2. Only az are allowed.

3. Replacing the more than withe spaces with one space and return the string.

Problem the only number are allowed always get me the error message even if there is no az.

Finally any suggestion or improvement to below code ?

I have made some update now please if their is any suggestion or improvement or any checks usual standard I have missed

Edit on 20/3/2016 1:12 PM GMT

GMT Time now :D

                public void input_validation()
    {
        string num_regex = @"^[0-9]*$";         //only digits allowed in this textbox
        string word_regex = @"[a-zA-Z]+";       //only a-z allowed in this textbox
        string Multi_spaces = @"\s+|\s{2,}";   //more than on white spaces

        Regex Nregex = new Regex(num_regex);
        Regex Wregex = new Regex(word_regex);
        Regex Mregex = new Regex(Multi_spaces);

        //To check all empty textbox within the groupbox
        foreach (var emptytxtbox in GB_CUST_INFO.Controls.OfType<TextBox>())
        {
            if (string.IsNullOrEmpty(emptytxtbox.Text.Trim()))
            {
                MessageBox.Show("Missing Information are no allowed\n","Missing Information",MessageBoxButtons.OK,MessageBoxIcon.Error);
                emptytxtbox.BackColor = Color.Red;
                return; //to stop the check on first empty textbox 
            }
            else
            {
                emptytxtbox.BackColor = Color.White; //to rest the color of missed info at pervious check
            }

            if (Mregex.IsMatch(emptytxtbox.Text))
            {
              //just replacing the more than one white spaces with one white space and retrun to its textbox
                emptytxtbox.Text = Mregex.Replace(emptytxtbox.Text," ");
            }
        }

        if (!Nregex.IsMatch(TB_CUST_PHONE1.Text))
        {
            MessageBox.Show("Only Number are allowed for phone number", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return;
        }
        else if (!Nregex.IsMatch(TB_CUST_PHONE2.Text))
        {
            MessageBox.Show("Only Number are allowed for mobile number", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return;
        }
        //else if (Mregex.IsMatch(TB_CUST_NAME.Text))
        //{   //just replacing the more than one white spaces with one white space and retrun to its textbox
        //    TB_CUST_NAME.Text = Mregex.Replace(TB_CUST_NAME.Text, " ");
        //}
        /*else if (Wregex.IsMatch(TB_CUST_NAME.Text))
        {
            MessageBox.Show("Only a-z are allowed");
        }*/
        else { cust_data_insert(); }
    }

Answer 1

如果我了解您的问题，请使用以下代码匹配文本框中的数字：

string num_regex = @"^[0-9]*$";   

Answer 2

To test for only numbers in your TextBox try the following regex:

string num_only_regex = @"[0-9]+$";

I've tested it myself an it works fine for me

Answer 3

Try:

var text = "abc12-   443";
var sanitizedText = string.Empty;

var result = Regex.Match(text, @"^[a-z0-9\s]+$",
             RegexOptions.IgnoreCase);

if (result.Success)
{
    sanitizedText = Regex.Replace(result.Value, "[ ]+", " ");
    Console.WriteLine(sanitizedText);
}
else
{
    Console.WriteLine("Invalid input: ({0})", text);
}

This should print:

abc12 443   #for abc12   443
Invalid input: (abc12-   443)     #for abc12- 443

See Demo here