我如何在c#中生成一个随机的8个字符的字母数字字符串?
当前回答
对于加密和非加密，有效地:
public static string GenerateRandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new Random().GenerateRandomString(length, charset);
public static string GenerateRandomString(this Random random, int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
RandomString(random.NextBytes, length, charset.ToCharArray());
public static string GenerateRandomCryptoString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
{
using (var crypto = new System.Security.Cryptography.RNGCryptoServiceProvider())
return crypto.GenerateRandomCryptoString(length, charset);
}
public static string GenerateRandomCryptoString(this RNGCryptoServiceProvider random, int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
RandomString(random.GetBytes, length, charset.ToCharArray());
private static string RandomString(Action<byte[]> fillRandomBuffer, int length, char[] charset)
{
if (length < 0)
throw new ArgumentOutOfRangeException(nameof(length), $"{nameof(length)} must be greater or equal to 0");
if (charset is null)
throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0)
throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
var maxIdx = charset.Length;
var chars = new char[length];
var randomBuffer = new byte[length * 4];
fillRandomBuffer(randomBuffer);
for (var i = 0; i < length; i++)
chars[i] = charset[BitConverter.ToUInt32(randomBuffer, i * 4) % maxIdx];
return new string(chars);
}
使用生成器和LINQ。不是最快的选项(特别是因为它不会一次生成所有字节)，但相当整洁和可扩展:
private static readonly Random _random = new Random();
public static string GenerateRandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new string(_random.GetGenerator().RandomChars(charset.ToCharArray()).Take(length).ToArray());
public static string GenerateRandomCryptoString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
{
using (var crypto = new System.Security.Cryptography.RNGCryptoServiceProvider())
return new string(crypto.GetGenerator().RandomChars(charset.ToCharArray()).Take(length).ToArray());
}
public static IEnumerable<char> RandomChars(this Func<uint, IEnumerable<uint>> randomGenerator, char[] charset)
{
if (charset is null)
throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0)
throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
return randomGenerator((uint)charset.Length).Select(r => charset[r]);
}
public static Func<uint, IEnumerable<uint>> GetGenerator(this Random random)
{
if (random is null)
throw new ArgumentNullException(nameof(random));
return GeneratorFunc_Inner;
IEnumerable<uint> GeneratorFunc_Inner(uint maxValue)
{
if (maxValue > int.MaxValue)
throw new ArgumentOutOfRangeException(nameof(maxValue));
return Generator_Inner();
IEnumerable<uint> Generator_Inner()
{
var randomBytes = new byte[4];
while (true)
{
random.NextBytes(randomBytes);
yield return BitConverter.ToUInt32(randomBytes, 0) % maxValue;
}
}
}
}
public static Func<uint, IEnumerable<uint>> GetGenerator(this System.Security.Cryptography.RNGCryptoServiceProvider random)
{
if (random is null)
throw new ArgumentNullException(nameof(random));
return Generator_Inner;
IEnumerable<uint> Generator_Inner(uint maxValue)
{
var randomBytes = new byte[4];
while (true)
{
random.GetBytes(randomBytes);
yield return BitConverter.ToUInt32(randomBytes, 0) % maxValue;
}
}
}
一个更简单的版本，使用LINQ只用于非加密字符串:
private static readonly Random _random = new Random();
public static string RandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new string(_random.GenerateChars(charset).Take(length).ToArray());
public static IEnumerable<char> GenerateChars(this Random random, string charset)
{
if (charset is null) throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0) throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
return random.Generator(charset.Length).Select(r => charset[r]);
}
public static IEnumerable<int> Generator(this Random random, int maxValue)
{
if (random is null) throw new ArgumentNullException(nameof(random));
return Generator_Inner();
IEnumerable<int> Generator_Inner() { while (true) yield return random.Next(maxValue); }
}
其他回答
对于加密和非加密，有效地:
public static string GenerateRandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new Random().GenerateRandomString(length, charset);
public static string GenerateRandomString(this Random random, int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
RandomString(random.NextBytes, length, charset.ToCharArray());
public static string GenerateRandomCryptoString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
{
using (var crypto = new System.Security.Cryptography.RNGCryptoServiceProvider())
return crypto.GenerateRandomCryptoString(length, charset);
}
public static string GenerateRandomCryptoString(this RNGCryptoServiceProvider random, int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
RandomString(random.GetBytes, length, charset.ToCharArray());
private static string RandomString(Action<byte[]> fillRandomBuffer, int length, char[] charset)
{
if (length < 0)
throw new ArgumentOutOfRangeException(nameof(length), $"{nameof(length)} must be greater or equal to 0");
if (charset is null)
throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0)
throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
var maxIdx = charset.Length;
var chars = new char[length];
var randomBuffer = new byte[length * 4];
fillRandomBuffer(randomBuffer);
for (var i = 0; i < length; i++)
chars[i] = charset[BitConverter.ToUInt32(randomBuffer, i * 4) % maxIdx];
return new string(chars);
}
使用生成器和LINQ。不是最快的选项(特别是因为它不会一次生成所有字节)，但相当整洁和可扩展:
private static readonly Random _random = new Random();
public static string GenerateRandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new string(_random.GetGenerator().RandomChars(charset.ToCharArray()).Take(length).ToArray());
public static string GenerateRandomCryptoString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
{
using (var crypto = new System.Security.Cryptography.RNGCryptoServiceProvider())
return new string(crypto.GetGenerator().RandomChars(charset.ToCharArray()).Take(length).ToArray());
}
public static IEnumerable<char> RandomChars(this Func<uint, IEnumerable<uint>> randomGenerator, char[] charset)
{
if (charset is null)
throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0)
throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
return randomGenerator((uint)charset.Length).Select(r => charset[r]);
}
public static Func<uint, IEnumerable<uint>> GetGenerator(this Random random)
{
if (random is null)
throw new ArgumentNullException(nameof(random));
return GeneratorFunc_Inner;
IEnumerable<uint> GeneratorFunc_Inner(uint maxValue)
{
if (maxValue > int.MaxValue)
throw new ArgumentOutOfRangeException(nameof(maxValue));
return Generator_Inner();
IEnumerable<uint> Generator_Inner()
{
var randomBytes = new byte[4];
while (true)
{
random.NextBytes(randomBytes);
yield return BitConverter.ToUInt32(randomBytes, 0) % maxValue;
}
}
}
}
public static Func<uint, IEnumerable<uint>> GetGenerator(this System.Security.Cryptography.RNGCryptoServiceProvider random)
{
if (random is null)
throw new ArgumentNullException(nameof(random));
return Generator_Inner;
IEnumerable<uint> Generator_Inner(uint maxValue)
{
var randomBytes = new byte[4];
while (true)
{
random.GetBytes(randomBytes);
yield return BitConverter.ToUInt32(randomBytes, 0) % maxValue;
}
}
}
一个更简单的版本，使用LINQ只用于非加密字符串:
private static readonly Random _random = new Random();
public static string RandomString(int length, string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890") =>
new string(_random.GenerateChars(charset).Take(length).ToArray());
public static IEnumerable<char> GenerateChars(this Random random, string charset)
{
if (charset is null) throw new ArgumentNullException(nameof(charset));
if (charset.Length == 0) throw new ArgumentException($"{nameof(charset)} must contain at least 1 character", nameof(charset));
return random.Generator(charset.Length).Select(r => charset[r]);
}
public static IEnumerable<int> Generator(this Random random, int maxValue)
{
if (random is null) throw new ArgumentNullException(nameof(random));
return Generator_Inner();
IEnumerable<int> Generator_Inner() { while (true) yield return random.Next(maxValue); }
}
public static string RandomString(int length)
{
const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var random = new Random();
return new string(Enumerable.Repeat(chars, length).Select(s => s[random.Next(s.Length)]).ToArray());
}
很可怕，我知道，但我就是忍不住:
namespace ConsoleApplication2
{
using System;
using System.Text.RegularExpressions;
class Program
{
static void Main(string[] args)
{
Random adomRng = new Random();
string rndString = string.Empty;
char c;
for (int i = 0; i < 8; i++)
{
while (!Regex.IsMatch((c=Convert.ToChar(adomRng.Next(48,128))).ToString(), "[A-Za-z0-9]"));
rndString += c;
}
Console.WriteLine(rndString + Environment.NewLine);
}
}
}
我听说LINQ是新的黑色，所以下面是我使用LINQ的尝试:
private static Random random = new Random();
public static string RandomString(int length)
{
const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
return new string(Enumerable.Repeat(chars, length)
.Select(s => s[random.Next(s.Length)]).ToArray());
}
(注意:Random类的使用使得它不适用于任何与安全性相关的事情，比如创建密码或令牌。如果你需要强随机数生成器，请使用RNGCryptoServiceProvider类。)
DTB解决方案的一个稍微干净的版本。
var chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
var random = new Random();
var list = Enumerable.Repeat(0, 8).Select(x=>chars[random.Next(chars.Length)]);
return string.Join("", list);
您的风格偏好可能会有所不同。
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