C#自定义函数NetxtString生成随机字符串

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！