利用drawing做图形验证码

Question

如题，讨论一下，有过这方面经验的老大有空出来指点一下。

Answer 1

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.IO;
using System.Web.UI;namespace NewWeb
{
/// <summary>
/// ValidateCode 的摘要说明。
///校验码类：生成5位数字校验码图片。
/// </summary>
public class ValidateCode
{
private Bitmap ValidateImage;
private Graphics  g;
private int AreaWidth;
private int AreaHeight;
private int AreaFontSize;
private string AreaFamilyName; public ValidateCode()
{
init();
ValidateImage=new Bitmap(AreaWidth,AreaHeight,PixelFormat.Format24bppRgb);
g=Graphics.FromImage(ValidateImage);
} private void init()
{
this.AreaWidth=56;
this.AreaHeight=18;
this.AreaFontSize=11;
this.AreaFamilyName="Verdana";
} public void SetValidateStyle(int width,int height,string familyName,int fontSize)
{
this.AreaWidth=width;
this.AreaHeight=height;
this.AreaFamilyName=familyName;
this.AreaFontSize=fontSize;
} public void DrawValidateCode(Page e,string i)
{
g.FillRectangle(new LinearGradientBrush(new Point(0,0),new Point(AreaWidth,AreaHeight),Color.FromArgb(255,255,255,255),Color.FromArgb(255,255,255,255)),0,0,120,30);


//添加干扰色
Random r=new Random();
for(int j=0;j<80;j++)
{
Pen p=new Pen(Color.FromArgb(r.Next(0,255),r.Next(0,255),r.Next(0,255)));
int PointW=r.Next(0,AreaWidth);
int PointH=r.Next(0,AreaHeight);
g.DrawLine(p,PointW,PointH,PointW+1,PointH); }
g.DrawString(i,new Font(AreaFamilyName,AreaFontSize,FontStyle.Bold),new SolidBrush(Color.Black),new PointF(0,0));
g.Save();
MemoryStream ms=new MemoryStream();
ValidateImage.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
   
e.Response.ClearContent();
e.Response.ContentType="image/gif";
e.Response.BinaryWrite(ms.ToArray());
e.Response.End();
} public string  RandomBigString()
{
char[] s = new char[]{'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'};
string num = "";
Random r = new Random();
for(int i = 0; i < 5; i++)
{
num += s[r.Next(0, s.Length)].ToString(); 
}
return num;
} public string RandownSmaillString()
{
char[] s = new char[]{'1', '2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','I','J','K','L','M','N','P','Q','R','S','T','U','V','W','X','Y','Z'};
string num = "";
Random r = new Random();
for(int i = 0; i < 5; i++)
{
num += s[r.Next(0, s.Length)].ToString(); 
}
return num; } }
}

Answer 2

http://lijunming.cnblogs.com/articles/355052.html
http://lijunming.cnblogs.com/articles/358409.html转别人的~~看看有没有用

Answer 3

验证码？
http://www.mikecat.net/blogview.asp?logID=1259&cateID=1
NickLee.Web.UI.Capach...什么控件可以

Answer 4

http://blog.csdn.net/qqwwee_com/archive/2006/02/09/595607.aspx

Answer 5

http://blog.csdn.net/Qqwwee_Com/archive/2005/08/14/454335.aspx

Answer 6

webwait(webwei)的那段代码有用吗？ 我试着好像不行呢。谁可以告诉我。 给分

Answer 7

看看这个,生成验证码的，我一直用的，还有问题在找我
 Bitmap newBitmap = new Bitmap(86, 26, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
        Graphics g = Graphics.FromImage(newBitmap);
        Random r = new Random();
        g.Clear(Color.White);
        System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, 86, 26), Color.Red, Color.Blue, 1.2f, true);
        
        for (int i = 0; i < 25; i++)
        {
            int x1 = r.Next(newBitmap.Width);
            int x2 = r.Next(newBitmap.Width);
            int y1 = r.Next(newBitmap.Height);
            int y2 = r.Next(newBitmap.Height);
            g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
        }
        for (int i = 0; i < 100; i++)
        {
            int x = r.Next(newBitmap.Width);
            int y = r.Next(newBitmap.Height);
            newBitmap.SetPixel(x, y, Color.FromArgb(r.Next()));
        }
        string value = GenerateRandom(4);
        Font font = new Font("黑体", 14, System.Drawing.FontStyle.Bold);
        g.DrawString(value, font, brush,2, 2);
        g.DrawRectangle(new Pen(Color.Silver),0,0,85,25);
        //g.FillRectangle(new SolidBrush(Color.Green), 0, 12, 80, 1);
        System.IO.MemoryStream ms = new System.IO.MemoryStream();
        newBitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
        Response.ClearContent();
        Response.ContentType = "image/gif";
        Response.BinaryWrite(ms.ToArray());
    }
    private static char[] constant =
        {
            '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','
        };
    public static string GenerateRandom(int Length)
    {
        System.Text.StringBuilder newRandom = new System.Text.StringBuilder(47);
        Random rd = new Random();
        for (int i = 0; i < Length; i++)
        {
            newRandom.Append(constant[rd.Next(47)]);
        }
        return newRandom.ToString();
    }

Answer 8

上面的页面是validatecode.aspx
在你需要用的页面，比如登录，添加一个Image控件，它的ImageUrl＝'validatecode.aspx'，就可以了。
上面漏了一句
 string value = GenerateRandom(4);
这里添加一句 Session["code"] = value;
然后你需要验证的页面，比如Login.aspx需要输入验证码的textbox
if(TextBox1.Text==Session["code"].ToString())
{
  //成功.....
}

Answer 9

webwait(webwei)的那段代码有用吗？ 我试着好像不行呢。谁可以告诉我。 给分
====
1.显示验证码的页面：
....
if(!Page.IsPostBack)
{
this.TextCode.Text="";
ValidateCode myCode=new ValidateCode();
Session["Vcode"]=myCode.RandomBigString();//或者 RandownSmaillString();
this.Image1.ImageUrl="Vcode.aspx";
}
....2.输出图像的页面(Vcode.aspx)的Page_Load里：
ValidateCode myCode=new ValidateCode();
myCode.DrawValidateCode(this,Session["Vcode"].ToString());

Answer 10

甜葡萄：你好 http://community.csdn.net//Expert/TopicView2.asp?id=4734851&datebasetype=now你提供的这个验证码我 测试了 可以成功 但是 有时会提示索引越界 
另外 我 在页面添加textbox 也看不到 为何？请教如何解决？？谢谢 打扰了

Answer 11

TO：hooyke(红旗下的蛋) 
  我知道那个越界的问题 越界是因为你的constant 字符数组个数不匹配   “甜葡萄”的字符数组只给出了36个 所以你改为
  public static string GenerateRandom(int Length)
    {
        System.Text.StringBuilder newRandom = new System.Text.StringBuilder(36);
        Random rd = new Random();
        for (int i = 0; i < Length; i++)
        {
            newRandom.Append(constant[rd.Next(36)]);
        }
        return newRandom.ToString();
    }
就OK了使用IMAGE控件：“上面的页面是validatecode.aspx
在你需要用的页面，比如登录，添加一个Image控件，它的ImageUrl＝'validatecode.aspx'，就可以了。”