asp.net域名检测

public bool IsValidDomain(string domain)
{
    if (string.IsNullOrEmpty(domain))
        return false;

    var regex = new Regex(@"^((?!-)[A-Za-z0-9-]{1,63}(?<!-)\.)+[A-Za-z]{2,6}$");
    return regex.IsMatch(domain);
}

public bool IsDomainResolvable(string domain)
{
    try
    {
        IPHostEntry entry = Dns.GetHostEntry(domain);
        return !string.IsNullOrEmpty(entry.HostName);
    }
    catch (SocketException)
    {
        return false;
    }
}

public async Task<bool> IsDomainAccessibleAsync(string domain)
{
    using (var client = new HttpClient())
    {
        try
        {
            var response = await client.GetAsync($"http://{domain}");
            return response.IsSuccessStatusCode;
        }
        catch (HttpRequestException)
        {
            return false;
        }
    }
}

public bool IsDomainSafe(string domain)
{
    // 假设有一个恶意域名列表
    var maliciousDomains = new List<string> { "malicious.com", "spam.org" };

    if (maliciousDomains.Contains(domain))
        return false;

    // 可以进一步使用第三方安全服务进行检测
    // 例如：https://www.virustotal.com/

    return true;
}