学步园

using System;<br /> using System.Data;<br /> using System.Configuration;<br /> using System.Web;<br /> using System.Web.Security;<br /> using System.Web.UI;<br /> using System.Web.UI.WebControls;<br /> using System.Web.UI.WebControls.WebParts;<br /> using System.Web.UI.HtmlControls;<br /> /// <summary><br /> /// randomCode 的摘要说明<br /> /// </summary><br /> public class randomCode<br /> {<br /> public randomCode()<br /> {<br /> //<br /> // TODO: 在此处添加构造函数逻辑<br /> //<br /> }<br /> /// <summary><br /> /// 验证码<br /> /// </summary><br /> /// <param name="n">验证码的个数</param><br /> /// <returns>返回生成的随机数</returns><br /> public string RandomNum(int n) //<br /> {<br /> string strchar = "0,1,2,3,4,5,6,7,8,9,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,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";<br /> string[] VcArray = strchar.Split(',');<br /> string VNum = ""; //<br /> int temp = -1; //记录上次随机数值，尽量避免产生几个一样的随机数<br /> //采用一个简单的<span class='wp_keywordlink'><a href="http://www.xuebuyuan.com/category/%E7%AE%97%E6%B3%95" title="算法" target="_blank">算法</a></span>以保证生成随机数的不同<br /> Random rand = new Random();<br /> for (int i = 1; i < n + 1; i++)<br /> {<br /> if (temp != -1)<br /> {<br /> rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));<br /> }<br /> int t = rand.Next(61);<br /> if (temp != -1 && temp == t)<br /> {<br /> return RandomNum(n);<br /> }<br /> temp = t;<br /> VNum += VcArray[t];<br /> }<br /> return VNum;//返回生成的随机数<br /> }<br /> }</p> <p>