我在自定义验证器中使用正则表达式来打印字母数字值，但它不起作用 [英] I am using regex in custom validator to print alphanumeric value but it is not working

问题描述

protected void CustomValidator2_ServerValidate(object source, ServerValidateEventArgs args)
   {

         
         System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex("([0-9a-z]{1,10})");
          args.IsValid = r.IsMatch(TextBox2.Text);


   }

推荐答案

上限+下限+数字。

Upper + Lower + Numbers.

(?-x)[0-9A-Za-z]{1,10}

更低+数字。

Lower + Numbers.

(?-x)[0-9a-z]{1,10}

你的表达错了，用这个测试了：

Your expression was wrong, tested it with this:

bool foundMatch = false;
try {
	foundMatch = Regex.IsMatch(subjectString, "([0-9a-z]{1,10})");
    } 
catch (ArgumentException ex)
    {
	// Syntax error in the regular expression
    }

你还应该在你的使用中加上 System.Text.RegularExpressions 。



我还想补充一点 {1,10} 由于缺少锚点而在原始表达式中没有做任何事情，并且几乎可以匹配任何东西。 />


以下测试（？ - x）[0-9A-Za-z] {1,10} 字符串：

You should also put System.Text.RegularExpressions in your Usings.

I also want to add that {1,10} isn't really doing anything in your original expression because of a lack of anchors and will match pretty much anything.

Tested (?-x)[0-9A-Za-z]{1,10} on the following strings:

abc123abc1
123812shdkfjs12g312t3
sdf6s876374kGFHGF26453165243
fsjdtfs7d65fs764123h1f2h3gfAHSGDF123
ASDASFJDSDFJHSksdgsdkfg123123123

每次输入方法时都不应创建正则表达式。最好将表达式变量添加为类的静态成员。



如解决方案1中所述，将RegularExpressions命名空间添加到您的使用中会更方便部分。

You should not create your regular expression every time you enter the method. It is better to add the expression variable as a static member of the class.

As suggested in Solution 1, it is more convenient to add the RegularExpressions namespace to your using section.

using System.Text.RegularExpressions;

private static Regex alphaNumExpression = new Regex("^[0-9a-z]{1,10}

，RegexOptions.IgnoreCase | RegexOptions.CultureInvariant）;

", RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);

请注意开始 ^ 并结束

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