如何初始化私有静态只读 HashSet<char> ?

Question

I want a private, constant member

private static readonly HashSet<char> _nameChars

in my controller, containing the characters ' ', 'a', 'A', ..., 'z', 'Z' . The purpose is for server-side validation of a form. But how do I initialize that HashSet ?

private static readonly HashSet<char> _nameChars = ?????

Is there a good way of doing that? I know that C++ has bracket initialization for std::set .

Answer 1

C# also has collection initializers:

 private static readonly HashSet<char> _nameChars = new HashSet<char> { 'a', 'b', ...};

You might also use a constructor that takes IEnumerable<T> argument:

private static readonly HashSet<char> _nameChars = new HashSet<char>("abcde...");

I find the 2nd approach more readable.

Answer 2

Alternative way:

static IReadOnlyCollection<char> ExcludedFields = new HashSet<char> {
        'a', 'b', ...
};