子字符串：

bool contains  = Directory.EnumerateFiles(path).Any(f => f.Contains("three"));

不区分大小写字符串：

Case-insensitive substring:

bool contains  = Directory.EnumerateFiles(path).Any(f => f.IndexOf("three", StringComparison.OrdinalIgnoreCase) > 0);

区分大小写的比较：

Case-insensitive comparison:

bool contains  = Directory.EnumerateFiles(path).Any(f => String.Equals(f, "myfilethree", StringComparison.OrdinalIgnoreCase));

获取文件名匹配通配符标准：

Get file names matching a wildcard criteria:

IEnumerable<string> files = Directory.EnumerateFiles(path, "three*.*"); // lazy file system lookup

string[] files = Directory.GetFiles(path, "three*.*"); // not lazy