Random String generator with number of alpha and numeric chars C# [duplicate]

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• How can I generate random alphanumeric strings in C#? 23 answers

can any help me with random string generator. I need to generate string with count of numbers and alphacharacters?

now i have this:

private static readonly Random Random = new Random((int)DateTime.Now.Ticks);
    private static string _alphaChars = "qwertyuiopasdfghjklzxcvbnm";
    private static string _numericChars = "1234567890";
    private static string RandomString(int size, string avaliable)
    {
        var chars = Enumerable.Range(0, size).Select(x => avaliable[Random.Next(0, avaliable.Length)]);
        return new string(chars.ToArray());
    }

but i need change this function to get parameters with count of numeric and alpha, and get string with this count? how i can do this? I need thay my string contains always, for example: with 4 alpha chars and 2 numeric. Count of this thinks must be like parameters