一个MVC4 下的验证码用法
先看一个核心验证码类(不用在意实现过程,直接copy就行),下面包含了两种验证码图片(原理一样),代码如下:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using System.Drawing.Imaging;
namespace TyMall.Util
{
public class Yzm : System.Web.UI.Page
{
#region 生成4个随机数
public string RandCode()
{
int CodeCount = 4;//生成4个随机数
string randomChar = "2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,J,K,L,M,N,P,Q,R,S,T,U,V,W,X,Y,Z";
randomChar = randomChar.Replace(",", "");
string RandomCode = "";
System.Threading.Thread.Sleep(3);
char[] allCharArray = randomChar.ToCharArray();
int n = allCharArray.Length;
System.Random random = new Random(~unchecked((int)DateTime.Now.Ticks));
for (int i = 0; i < CodeCount; i++)
{
int rnd = random.Next(0, n);
RandomCode += allCharArray[rnd];
}
return RandomCode;
}
#endregion
#region 验证码--方式1
/// <summary>
/// 验证码--方式1 创建验证码图片
/// </summary>
/// <param name="randomcode">验证码</param>
public byte[] CreateImage(string randomcode)
{
int randAngle = 40; //随机转动角度
int mapwidth = (int)(randomcode.Length * 18);
Bitmap map = new Bitmap(mapwidth, 24);//创建图片背景
Graphics graph = Graphics.FromImage(map);
graph.Clear(Color.White);//清除画面，填充背景
//graph.DrawRectangle(new Pen(Color.Silver, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框
Random rand = new Random();
//验证码旋转，防止机器识别
char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组
//文字距中
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
//定义颜色
Color[] c = { Color.Black, Color.Red, Color.Blue, Color.Green,
Color.Orange, Color.Brown, Color.DarkBlue };
//画图片的背景噪音线
for (int i = 0; i < 2; i++)
{
int x1 = rand.Next(10);
int x2 = rand.Next(map.Width - 10, map.Width);
int y1 = rand.Next(map.Height);
int y2 = rand.Next(map.Height);
graph.DrawLine(new Pen(c[rand.Next(7)]), x1, y1, x2, y2);
}
for (int i = 0; i < chars.Length; i++)
{
int cindex = rand.Next(7);
int findex = rand.Next(5);
Font f = new System.Drawing.Font("Arial", 18, System.Drawing.FontStyle.Regular);//字体样式(参数2为字体大小)
Brush b = new System.Drawing.SolidBrush(c[cindex]);
Point dot = new Point(12, 16);
float angle = rand.Next(-randAngle, randAngle);//转动的度数
graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置
graph.RotateTransform(angle);
graph.DrawString(chars[i].ToString(), f, b, 1, 1, format);
graph.RotateTransform(-angle);//转回去
graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置
}
//生成图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
MemoryStream stream = new MemoryStream();
map.Save(stream, ImageFormat.Jpeg);
graph.Dispose();
map.Dispose();
return stream.ToArray();
}
#endregion
#region 验证码--方式2
/// <summary>
/// 验证码--方式2
/// </summary>
/// <param name="chkCode">验证码</param>
/// <returns></returns>
public Byte[] CreateImage2(string chkCode)
{
//颜色列表，用于验证码、噪线、噪点
Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.Brown, Color.DarkBlue };
//字体列表，用于验证码
string[] font = { "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" };
Random rnd = new Random();
Bitmap bmp = new Bitmap(100, 40);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
//画噪线
for (int i = 0; i < 3; i++)
{
int x1 = rnd.Next(100);
int y1 = rnd.Next(40);
int x2 = rnd.Next(100);
int y2 = rnd.Next(40);
Color clr = color[rnd.Next(color.Length)];
g.DrawLine(new Pen(clr), x1, y1, x2, y2);
}
//画验证码字符串
for (int i = 0; i < chkCode.Length; i++)
{
string fnt = font[rnd.Next(font.Length)];
Font ft = new Font(fnt, 18);
Color clr = color[rnd.Next(color.Length)];
g.DrawString(chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 8, (float)8);
}
//画噪点
for (int i = 0; i < 20; i++)
{
int x = rnd.Next(bmp.Width);
int y = rnd.Next(bmp.Height);
Color clr = color[rnd.Next(color.Length)];
bmp.SetPixel(x, y, clr);
}
MemoryStream ms = new MemoryStream();
try
{
bmp.Save(ms, ImageFormat.Png);
return ms.ToArray();
}
finally
{
//显式释放资源
bmp.Dispose();
g.Dispose();
}
}
#endregion
}
}
然后需要在控制器中实现访问的方式(其实就是写一个action,把生成的image文件返回给view)
/// <summary>
/// 验证码,形状一
/// </summary>
/// <returns></returns>
public ActionResult Yzm()
{
TyMall.Util.Yzm sc = new TyMall.Util.Yzm();
string vVerificationCode = sc.RandCode();
Session["vcode"] = null;
Session("vcode", vVerificationCode.ToLower()); //Session中保存验证码
sc.CreateImage(vVerificationCode);
return File(sc.CreateImage(vVerificationCode), @"image/jpeg");
}
/// <summary>
///验证码,形状二
/// </summary>
/// <returns></returns>
public ActionResult Yzm2()
{
TyMall.Util.Yzm sc = new TyMall.Util.Yzm();
string vVerificationCode = sc.RandCode();
Session["vcode"] = null;
Session("vcode", vVerificationCode.ToLower()); //Session中保存验证码
sc.CreateImage(vVerificationCode);
return File(sc.CreateImage2(vVerificationCode), @"image/jpeg");
}
view中访问方式(就是image的最原始展示方式)
<img id="yzm" src="/控制器名称/yzm" /> <img id="yzm" src="/控制器名称/yzm2" />
生成如下:
OK 可以了