C#中实现验证码的参考代码-白红宇

C#中实现验证码的参考代码

阅读量：6157 次

发布时间：2019-06-21

本文共 3959 字，大约阅读时间需要 13 分钟。

生成验证码的方法

using System;using System.Collections;using System.Configuration;using System.Data;using System.Linq;using System.Web;using System.Web.Security;using System.Web.UI;using System.Drawing;using System.Drawing.Imaging;using System.IO;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Xml.Linq;public partial class YanZhengMa : System.Web.UI.Page{    protected void Page_Load(object sender, EventArgs e)    {        //  首先调用RndNum函数生成4位数字的验证码        string str_ValidateCode = RndNum(4);        //  然后把它保存在用于验证的Session里边        Session["imageCode"] = str_ValidateCode;        //调用CreateImage函数，把验证码绘制到图片中        CreateImage(str_ValidateCode);    }    private string RndNum(int VcodeNum)    {        string Vchar = "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";        string[] VcArray = Vchar.Split(new Char[] { ',' });        string VNum = "";        //int temp = -1;        Random rand = new Random();        for (int i = 1; i < VcodeNum + 1; i++)        {            int t = rand.Next(36);            VNum += VcArray[t];        }        return VNum;    }    //生成随机颜色    private Color GetRandomColor()    {        Random RandomNum_First = new Random((int)DateTime.Now.Ticks);        //  对于C#的随机数，没什么好说的        System.Threading.Thread.Sleep(RandomNum_First.Next(50));        Random RandomNum_Sencond = new Random((int)DateTime.Now.Ticks);        //  为了在白色背景上显示，尽量生成深色        int int_Red = RandomNum_First.Next(256);        int int_Green = RandomNum_Sencond.Next(256);        int int_Blue = (int_Red + int_Green > 400) ? 0 : 400 - int_Red - int_Green;        int_Blue = (int_Blue > 255) ? 255 : int_Blue;        return Color.FromArgb(int_Red, int_Green, int_Blue);    }    public void CreateImage(string str_ValidateCode)    {        int int_ImageWidth = str_ValidateCode.Length * 13;        Random newRandom = new Random();        //  图高20px        Bitmap theBitmap = new Bitmap(int_ImageWidth, 20);        Graphics theGraphics = Graphics.FromImage(theBitmap);        //  白色背景        theGraphics.Clear(Color.White);        //  灰色边框        theGraphics.DrawRectangle(new Pen(Color.LightGray, 1), 0, 0, int_ImageWidth - 1, 19);        //  10pt的字体        Font theFont = new Font("Arial", 10);        for (int int_index = 0; int_index < str_ValidateCode.Length; int_index++)        {            string str_char = str_ValidateCode.Substring(int_index, 1);            Brush newBrush = new SolidBrush(GetRandomColor());            Point thePos = new Point(int_index * 13 + 1 + newRandom.Next(3), 1 + newRandom.Next(3));            theGraphics.DrawString(str_char, theFont, newBrush, thePos);        }        //  将生成的图片发回客户端        MemoryStream ms = new MemoryStream();        theBitmap.Save(ms, ImageFormat.Jpeg);        Response.ClearContent(); //需要输出图象信息 要修改HTTP头         Response.ContentType = "image/Png";        Response.BinaryWrite(ms.ToArray());        theGraphics.Dispose();        theBitmap.Dispose();        Response.End();    }}

在前台调用的时候的部分代码