private IList <char> GetAlphaCharacters(AlphaCase alphaCase)
{
switch (alphaCase)
{
case AlphaCase.Lower:
return(LowerAlphaChars);
case AlphaCase.Upper:
return(UpperAlphaChars);
case AlphaCase.Both:
default:
return(new List <char>(LowerAlphaChars.Concat(UpperAlphaChars)));
}
}
public string Generate(int length, int minNumeric = 0, int minAlpha = 0, AlphaCase alphaCase = AlphaCase.Both)
{
if (length < 0)
{
throw new ArgumentOutOfRangeException("length");
}
if (minNumeric < 0)
{
throw new ArgumentOutOfRangeException("minNumeric");
}
if (minAlpha < 0)
{
throw new ArgumentOutOfRangeException("minAlpha");
}
if (length < minNumeric + minAlpha)
{
throw new ArgumentException();
}
if (length == 0)
{
return(string.Empty);
}
var result = new char[length];
var index = 0;
foreach (var numeric in GenerateNumeric().Take(minNumeric))
{
result[index++] = numeric;
}
var alphaCharacters = GetAlphaCharacters(alphaCase);
foreach (var alpha in Generate(alphaCharacters).Take(minAlpha))
{
result[index++] = alpha;
}
var restLength = length - index;
if (restLength > 0)
{
var restCharacters = new List <char>(NumericChars.Concat(alphaCharacters));
foreach (var rest in Generate(restCharacters).Take(restLength))
{
result[index++] = rest;
}
}
// shuffle result
return(new string(result.OrderBy(x => Rnd.Next()).ToArray()));
}