C＃使用RegEx提取字符串的两个元素

Question

I've got the following string which I extracted from a POST request using .Split() .

I need to extract the e-mail ( login_email= ) and the password ( login_password= ).

login_cmd=&login_params=&login_email=my%40mail.de&login_password=TOPsecret&submit..........

All in all I need to get:

my%40mail.de

TOPsecret

Is there an easy way, maybe without using RegEx, or is writing a RegEx for this easy to learn? I know the RegEx for extracting the e-mail address should start after login_email= and stop at the & sign.

Answer 1

I would say the easiest is to not use regex, but use the built in HttpUtility:

string param1 = HttpUtility.ParseQueryString(myUri.Query).Get("login_email");

Simples.

Answer 2

Use lookarounds like below.

(?<=login_(?:email|password)=)[^&]*(?=&)

OR

(?<=login_(?:email|password)=)[^&]*

Lookafter to login_email= or login_password and match any character but not of & zero or more times.

String input = @"login_cmd=&login_params=&login_email=my%40mail.de&login_password=TOPsecret&submit..........";
Regex rgx = new Regex(@"(?<=login_(?:email|password)=)[^&]*");
foreach (Match m in rgx.Matches(input))
Console.WriteLine(m.Groups[0].Value);

IDEONE

String input = @"login_cmd=&login_params=&login_email=my%40mail.de&login_password=TOPsecret&submit..........";

Regex rgx = new Regex(@"(?<=login_email=)([^&]+)|(?<=login_password=)([^&]+)");

foreach (Match m in rgx.Matches(input))
{
    if(!m.Groups[1].Value.ToString().Equals(string.Empty))
    {
        Console.WriteLine("Email : " + m.Groups[1].Value);
    }
        if(!m.Groups[2].Value.ToString().Equals(string.Empty))
    {
        Console.WriteLine("Password : " + m.Groups[2].Value);
    }
}

IDEONE

Answer 3

(?<=login_email=)[^&]+|(?<=login_password=)[^&]+

Try this.See demo.

http://regex101.com/r/hQ9xT1/16