/// <summary>
/// 随机打乱字符串中的所有字符
/// </summary>
/// <param name="str">需要被打乱的字符串</param>
/// <param name="seed">种子</param>
/// <returns>被打乱的字符串</returns>
public static string Shuffle(string str, int?seed = null)
{
KGuard.Requires <ArgumentNullException>(str != null);
var random = KUtil.MakeRandom(seed);
var requested = new string[str.Length];
for (var i = 0; i < str.Length; i++)
{
var index = random.Next(0, str.Length - 1);
requested[i] = requested[i] ?? str.Substring(i, 1);
requested[index] = requested[index] ?? str.Substring(index, 1);
if (index == i)
{
continue;
}
var temp = requested[i];
requested[i] = requested[index];
requested[index] = temp;
}
return(KArray.Reduce(requested, (v1, v2) => v1 + v2, string.Empty));
}
/// <summary>
/// 生成一个随机字母（含大小写），数字的字符串。
/// </summary>
/// <param name="length">字符串长度</param>
/// <param name="seed">种子</param>
/// <returns>随机的字符串</returns>
public static string Random(int length = 16, int?seed = null)
{
KGuard.Requires <ArgumentOutOfRangeException>(length > 0);
var requested = string.Empty;
var random = KUtil.MakeRandom(seed);
for (int len; (len = requested.Length) < length;)
{
var size = length - len;
var bytes = new byte[size];
random.NextBytes(bytes);
var code = Replace(new[] { "/", "+", "=" }, string.Empty, Convert.ToBase64String(bytes));
requested += code.Substring(0, Math.Min(size, code.Length));
}
return(requested);
}
/// <summary>
/// 将规定数组中的元素打乱
/// </summary>
/// <typeparam name="T">数组类型</typeparam>
/// <param name="source">规定数组</param>
/// <param name="seed">种子</param>
/// <returns>打乱后的数组</returns>
public static T[] Shuffle <T>(T[] source, int?seed = null)
{
KGuard.Requires <ArgumentNullException>(source != null);
var requested = new T[source.Length];
Array.Copy(source, requested, source.Length);
var random = KUtil.MakeRandom(seed);
for (var i = 0; i < requested.Length; i++)
{
var index = random.Next(0, requested.Length - 1);
if (index == i)
{
continue;
}
var temp = requested[i];
requested[i] = requested[index];
requested[index] = temp;
}
return(requested);
}
