## 1、生成指定返回随机数 ``` /// <summary> /// 生成一个指定范围的随机整数，该随机数范围包括最小值，但不包括最大值 /// </summary> /// <param name="minNum">最小值</param> /// <param name="maxNum">最大值</param> public int GetRandomInt(int minNum, int maxNum) { return this._random.Next(minNum, maxNum); } ``` ## 用法 ``` RandomHelper r = new RandomHelper(); int k= r.GetRandomInt(111, 222);//返回111-222之间随机数 ``` ## 2、生成一个0.0到1.0的随机小数 ``` /// <summary> /// 生成一个0.0到1.0的随机小数 /// </summary> public double GetRandomDouble() { return this._random.NextDouble(); } ``` ## 用法 ``` RandomHelper r = new RandomHelper(); double k = r.GetRandomDouble();//返回0.275322388520149 ``` ## 3、多数组随机排序 ``` /// <summary> /// 对一个数组进行随机排序 /// </summary> /// <typeparam name="T">数组的类型</typeparam> /// <param name="arr">需要随机排序的数组</param> public void GetRandomArray<T>(T[] arr) { //对数组进行随机排序的算法:随机选择两个位置，将两个位置上的值交换 //交换的次数,这里使用数组的长度作为交换次数 int count = arr.Length; //开始交换 for (int i = 0; i < count; i++) { //生成两个随机数位置 int randomNum1 = GetRandomInt(0, arr.Length); int randomNum2 = GetRandomInt(0, arr.Length); //定义临时变量 T temp; //交换两个随机数位置的值 temp = arr[randomNum1]; arr[randomNum1] = arr[randomNum2]; arr[randomNum2] = temp; } } ``` ## 用法 ``` string[] sarr = { "1", "2", "3", "4", "5" }; RandomHelper r = new RandomHelper(); r.GetRandomArray(sarr);//对数组随机排序 foreach (string s in sarr) { Response.Write(s);//返回 51324 这里仅仅是用法举例，还有许多用法 } ``` ## 4、随机生成不重复字符串数字和字母混和 ``` public string GenerateCheckCode(int codeCount) { string str = string.Empty; long num2 = DateTime.Now.Ticks + this.rep; this.rep++; Random random = new Random(((int)(((ulong)num2) & 0xffffffffL)) | ((int)(num2 >> this.rep))); for (int i = 0; i < codeCount; i++) { char ch; int num = random.Next(); if ((num % 2) == 0) { ch = (char)(0x30 + ((ushort)(num % 10))); } else { ch = (char)(0x41 + ((ushort)(num % 0x1a))); } str = str + ch.ToString(); } return str; } ``` ## 用法 ``` RandomHelper r = new RandomHelper(); string k= r.GenerateCheckCode(5); Response.Write(k);//返回8JBTD ``` ## 5、随机生成不重复字符串（纯数字） ``` // 一：随机生成不重复数字字符串 private int rep = 0; public string GenerateCheckCodeNum(int codeCount) { string str = string.Empty; long num2 = DateTime.Now.Ticks + this.rep; this.rep++; Random random = new Random(((int)(((ulong)num2) & 0xffffffffL)) | ((int)(num2 >> this.rep))); for (int i = 0; i < codeCount; i++) { int num = random.Next(); str = str + ((char)(0x30 + ((ushort)(num % 10)))).ToString(); } return str; } ``` ## 用法 ``` RandomHelper r = new RandomHelper(); string k= r.GenerateCheckCodeNum(5); Response.Write(k);//返回 20447 ``` ## 6、从字符串里得到随机规定的字符数[不推荐用] ``` /// <summary> /// 从字符串里随机得到，规定个数的字符串. /// </summary> /// <param name="allChar"></param> /// <param name="CodeCount"></param> /// <returns></returns> private string GetRandomCode(string allChar, int CodeCount) { //string allChar = "1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,i,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z"; string[] allCharArray = allChar.Split(','); string RandomCode = ""; int temp = -1; Random rand = new Random(); for (int i = 0; i < CodeCount; i++) { if (temp != -1) { rand = new Random(temp * i * ((int)DateTime.Now.Ticks)); } int t = rand.Next(allCharArray.Length - 1); while (temp == t) { t = rand.Next(allCharArray.Length - 1); } temp = t; RandomCode += allCharArray[t]; } return RandomCode; } ``` ## 用法