本文实例展示了C#自定义函数NetxtString实现生成随机字符串的方法，在进行C#项目开发中非常实用！分享给大家供大家参考。

一、生成随机字符串

关键代码如下：

/// <summary>/// 生成随机字符串/// </summary>/// <param name="random">Random</param>/// <param name="size">字符串长度</param>/// <param name="lowerCase">字符串是小写</param>/// <returns>随机字符串</returns>public static string NetxtString(this Random random, int size, bool lowerCase){ StringBuilder _builder = new StringBuilder(size); int _startChar = lowerCase ? 97 : 65;//65 = A / 97 = a for (int i = 0; i < size; i++) _builder.Append((char)(26 * random.NextDouble() + _startChar)); return _builder.ToString();}

测试代码如下：

static void Main(string[] args){ try { Random _random = new Random(); for (int i = 0; i < 10; i++) { Console.WriteLine(_random.NetxtString(4, false)); } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { Console.ReadLine(); }}

测试结果如下图所示：

二、根据指定字符生成随机字符串

关键代码如下：

/// <summary>/// 0~9 A~Z字符串/// </summary>public static string RandomString_09AZ = "0123456789ABCDEFGHIJKMLNOPQRSTUVWXYZ";/// <summary>/// 依据指定字符串来生成随机字符串/// </summary>/// <param name="random">Random</param>/// <param name="randomString">指定字符串</param>/// <param name="size">字符串长度</param>/// <param name="lowerCase">字符串是小写</param>/// <returns>随机字符串</returns>public static string NetxtString(this Random random, string randomString, int size, bool lowerCase){ string _nextString = string.Empty; if (random != null && !string.IsNullOrEmpty(randomString)) { StringBuilder _builder = new StringBuilder(size); int _maxCount = randomString.Length - 1; for (int i = 0; i < size; i++) { int _number = random.Next(0, _maxCount); _builder.Append(randomString[_number]); } _nextString = _builder.ToString(); } return lowerCase ? _nextString.ToLower() : _nextString.ToUpper();}

测试代码如下：

static void Main(string[] args){ try { Random _random = new Random(); string _ramdomString = RandomToolV2.RandomString_09AZ; for (int i = 0; i < 20; i++) { // Console.WriteLine(_random.NetxtString(4, false)); Console.WriteLine(_random.NetxtString(_ramdomString, 4, false)); } } catch (Exception ex) { Console.WriteLine(ex.Message); } finally { Console.ReadLine(); }}

代码运行效果如下图所示：

希望本文所述实例对大家的C#学习能够有所帮助！