Question

全部明确

string[] names = { "Tom", "Dick", "Harry", "Mary", "Jay" };

IEnumerable<string> query = names
    .Where   (n => n.Contains ("a"))

我真正需要的是什么

string[] providers = { "gmail", "yahoo", "hotmail" , "something" };

并使用LINQ确定（不一定返回IEnumerable，bool会这样做）是否某些电子邮件地址某人@ 某事 .com来自此提供程序列表，即数组提供程序的元素是不区分大小写的子字符串电子邮件地址。

Answer 1

您是要处理个人电子邮件还是收集em？

// individual
var email = ...;
var isValid = providers.Any(p => email.IndexOf(p, StringComparison.OrdinalIgnoreCase) != -1);

// collection
var emails = new[] { ... };
var validEmails = emails.Where(e => providers.Any(p => e.IndexOf(p, StringComparison.OrdinalIgnoreCase) != -1));

Answer 2

你可以使用它。

string[] providers = { "gmail", "yahoo", "hotmail", "something" };
string inputEmail1 = "test@gmail.com";
string inputEmail2 = "test@gmail2.com";
var query = from n in providers
            where inputEmail1.ToLower().Contains("@" + n + ".")
            select n;

Console.WriteLine(query.Count()); //For inputeEmail1,Print 1. For inputeEmail2, it will print 0

Answer 3

这将检查提供的电子邮件地址 domain 是否存在于域列表中。它会提供一个布尔。

string email = "me@hello.com";

string[] domains = new string[]{"hello", "goodbye"};

bool exists = new List<string>(domains).Exists(x => email.Conatains(string.Format(@"@{0}\.", x);

Answer 4

我猜你想要对'@'和第一个'。'之间的文本进行不区分大小写的匹配。

所以，这是我的方法：

var providers = new []
    { "gmail", "yahoo", "hotmail", "something" };

var inputEmail = "test@gmail.com";

var match = inputEmail.Split('@')[1].Split('.')[0];
// You should probably expand this out to check for error in the input string.

Func<string, bool> isMatch =
    p => String.Compare(match, p, true) == 0;

var query =
    from p in providers
    where isMatch(p)
    select p;

var contains = query.Any();

我尝试将查询的详细信息删除到Func，以使查询更加“简单”。

Linq对象的变体包含

4 个答案: