编辑“︁C Sharp 正则表达式”︁（章节）

== 实际应用案例 ==

=== 案例1：验证电子邮件格式 ===
<syntaxhighlight lang="csharp">
bool IsValidEmail(string email) {
    string pattern = @"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$";
    return Regex.IsMatch(email, pattern);
}

Console.WriteLine(IsValidEmail("test@example.com"));  // true
Console.WriteLine(IsValidEmail("invalid.email"));    // false
</syntaxhighlight>

=== 案例2：提取日志信息 ===
<syntaxhighlight lang="csharp">
string logEntry = "[2023-04-01 14:30:22] ERROR: File not found";
string pattern = @"^\[(.+?)\]\s+(\w+):\s+(.+)$";

Match m = Regex.Match(logEntry, pattern);
if (m.Success) {
    Console.WriteLine($"Timestamp: {m.Groups[1].Value}");
    Console.WriteLine($"Log Level: {m.Groups[2].Value}");
    Console.WriteLine($"Message: {m.Groups[3].Value}");
}
</syntaxhighlight>

输出：
<pre>
Timestamp: 2023-04-01 14:30:22
Log Level: ERROR
Message: File not found
</pre>