c# - 正则表达式，仅接受数字（0-9）和无字符[重复](Regex that accepts only numbers (0-9) and NO characters [duplicate])

Question

This question already has an answer here:

(这个问题已经在这里有了答案：)

• Regex for numbers only 17 answers

  (正则表达式仅用于数字 17答案)

I need a regex that will accept only digits from 0-9 and nothing else.

(我需要一个正则表达式，它将只接受0-9之间的数字，而不能接受其他任何东西。)

No letters, no characters.

(没有字母，没有字符。)

I thought this would work:

(我认为这可以工作：)

^[0-9]

or even

(甚至)

d+

but these are accepting the characters : ^,$,(,), etc

(但这些接受字符：^，$，（，）等)

I thought that both the regexes above would do the trick and I'm not sure why its accepting those characters.

(我以为上面的两个正则表达式都可以解决问题，我不确定为什么它接受那些字符。)

EDIT:

(编辑：)

This is exactly what I am doing:

(这正是我在做什么：)

 private void OnTextChanged(object sender, EventArgs e)
    {

   if (!System.Text.RegularExpressions.Regex.IsMatch("^[0-9]", textbox.Text))
        {
            textbox.Text = string.Empty;
        }
    }

This is allowing the characters I mentioned above.

(这允许我上面提到的字符。)

  ask by mo alaz translate from so

Answer 1

Your regex ^[0-9] matches anything beginning with a digit, including strings like "1A".

(您的正则表达式^[0-9]匹配以数字开头的任何内容，包括“ 1A”之类的字符串。)

To avoid a partial match, append a $ to the end:

(为了避免部分匹配，请在末尾附加$ ：)

^[0-9]*$

This accepts any number of digits, including none.

(这可以接受任意数量的数字，包括无数字。)

To accept one or more digits, change the * to + .

(要接受一个或多个数字，请将*更改为+ 。)

To accept exactly one digit, just remove the * .

(要只接受一位数字，只需删除* 。)

UPDATE: You mixed up the arguments to IsMatch .

(更新：您混合了IsMatch的参数。)

The pattern should be the second argument, not the first:

(模式应该是第二个参数，而不是第一个：)

if (!System.Text.RegularExpressions.Regex.IsMatch(textbox.Text, "^[0-9]*$"))

CAUTION: In JavaScript, \d is equivalent to [0-9] , but in .NET, \d by default matches any Unicode decimal digit , including exotic fare like ? (Myanmar 2) and ? (N'Ko 9).

(注意：在JavaScript中， \d等效于[0-9] ，但在.NET中， \d默认情况下匹配任何Unicode十进制数字 ，包括诸如?（缅甸2）和?（N'Ko 9）之类的奇特票价。)

Unless your app is prepared to deal with these characters, stick with [0-9] (or supply the RegexOptions.ECMAScript flag).

(除非您的应用程序准备好处理这些字符，否则请坚持使用[0-9] （或提供RegexOptions.ECMAScript标志）。)