这篇文章主要介绍“如何使用.net生成验证码”，在日常操作中，相信很多人在如何使用.net生成验证码问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答”如何使用.net生成验证码”的疑惑有所帮助！接下来，请跟着小编一起来学习吧！
先给大家看看效果图：
页面代码：
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>验证码</title>
<script type="text/javascript">
//换一张
function change() {
var img = document.getElementById("ValidateCode");
img.src = img.src + '?';
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<th>
验证码
</th>
<td>
<asp:TextBox runat="server" ID="tbCheckCode" CssClass="Small" MaxLength="4"></asp:TextBox>
</td>
<td>
<img src="VerifyCode.aspx" id="ValidateCode" alt="换一张" onclick="javascript:change()" />
</td>
<td>
<a id="ChangeCode" href="#" onclick="javascript:change()">换一张</a>
</td>
</tr>
<tr>
<td>
<asp:Button runat="server" ID="LoginSubmit" OnClick="LoginSubmits" Text="登录" />
</td>
</tr>
</table>
</div>
</form>
</body>
</html>后台代码:
/// <summary>
/// 登录
/// </summary>
/// <param name="sender"></param>
protected void LoginSubmits(object sender, EventArgs e)
{
CheckLogin();
}
#region 私有方法
#region
public static Boolean IsNotNull(Object str)
{
return !IsNull(str);
}
public static Boolean IsNull(Object str)
{
return str == null;
}
public static void Show(System.Web.UI.Page page, string msg)
{
page.ClientScript.RegisterStartupScript(page.GetType(), "message",
"<script language='javascript' defer>alert('" + msg.ToString() + "');</script>");
}
#endregion
private void CheckLogin()
{
if (tbCheckCode.Text.Trim() == "")
{
Show(this, "验证码不能为空!");
return;
}
else
{
if (IsNotNull(Session["ValidateCheckCode"]))
{
if (tbCheckCode.Text.Trim() != Session["ValidateCheckCode"].ToString())
{
Show(this, "验证码填写不正确!");
tbCheckCode.Text = "";
return;
}
}
else
{
Show(this, "请刷新验证码！");
return;
}
}
}
#endregion
}
}生成验证码:
using System;
using System.Drawing;
using System.Text;
using System.Web;
namespace Web.TEXT
{
public partial class VerifyCode : System.Web.UI.Page
{
public Encoding GB = Encoding.GetEncoding("GB2312");
protected void Page_Load(object sender, EventArgs e)
{
VerifyCode v = new VerifyCode();
v.Length = this.length;
v.FontSize = this.fontSize;
v.Chaos = this.chaos;
v.BackgroundColor = this.backgroundColor;
v.ChaosColor = this.chaosColor;
v.CodeSerial = this.codeSerial;
v.Colors = this.colors;
v.Fonts = this.fonts;
v.Padding = this.padding;
string code = v.CreateVerifyCode(); //取随机码
v.CreateImageOnPage(code, this.Context); // 输出图片
Response.Cookies.Add(new HttpCookie("CheckCode", code.ToUpper())); // 使用Cookies取验证码的值
System.Web.HttpContext.Current.Session["ValidateCheckCode"] = code;
//return checkCode;
}
#region 验证码长度(默认4个验证码的长度)
private int length = 4;
public int Length
{
get { return length; }
set { length = value; }
}
#endregion
#region 验证码字体大小(为了显示扭曲效果，默认40像素，可以自行修改)
private int fontSize = 12;
public int FontSize
{
get { return fontSize; }
set { fontSize = value; }
}
#endregion
#region 边框补(默认1像素)
private int padding = 1;
public int Padding
{
get { return padding; }
set { padding = value; }
}
#endregion
#region 是否输出燥点(默认不输出)
private bool chaos = true;
public bool Chaos
{
get { return chaos; }
set { chaos = value; }
}
#endregion
#region 输出燥点的颜色(默认灰色)
private Color chaosColor = Color.LightGray;
public Color ChaosColor
{
get { return chaosColor; }
set { chaosColor = value; }
}
#endregion
#region 自定义背景色(默认白色)
private Color backgroundColor = Color.White;
public Color BackgroundColor
{
get { return backgroundColor; }
set { backgroundColor = value; }
}
#endregion
#region 自定义随机颜色数组
private Color[] colors =
{
Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown,
Color.DarkCyan, Color.Purple
};
public Color[] Colors
{
get { return colors; }
set { colors = value; }
}
#endregion
#region 自定义字体数组
private string[] fonts = {"Arial", "Georgia"};
public string[] Fonts
{
get { return fonts; }
set { fonts = value; }
}
#endregion
#region 自定义随机码字符串序列(使用逗号分隔)
private string codeSerial = "0,1,2,3,4,5,6,7,8,9";
// string codeSerial = "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 codeSerial = "殃,央,鸯,秧,杨,扬,佯,疡,羊,洋,阳,氧,仰,痒,养,样,漾,邀,腰,妖,瑶,摇,尧,遥,窑,谣,姚,咬,舀,药,要,耀,椰,噎,耶,爷,野,冶,也,页,掖,业,叶,曳,腋,夜,液,一,壹,医,揖,铱,依,伊,衣,颐,夷,遗,移,仪,胰,疑,沂,宜,姨,彝,椅,蚁,倚,已,乙,矣,以,艺,抑,易,邑,屹,亿,役,臆,逸,肄,疫,亦,裔,意,毅,忆,义,益,溢,诣,议,谊,译,异,翼,翌,绎,茵,荫,因,殷,音,阴,姻,吟,银,淫,寅,饮,尹,引,隐,印,英,樱,婴,鹰,应,缨,莹,萤,营,荧,蝇,迎,赢,盈,影,颖,硬,映,哟,拥,佣,臃,痈,庸,雍,踊,蛹,咏,泳,涌,永,恿,勇,用,幽,优,悠,忧,尤,由,邮,铀,犹,油,游,酉,有,友,右,佑,釉,诱,又,幼,迂,淤,于,盂,榆,虞,愚,舆,余,俞,逾,鱼,愉,渝,渔,隅,予,娱,雨,与,屿,禹,株,蛛,朱,猪,诸,诛,逐,竹,烛,煮,拄,瞩,嘱,主,著,柱,助,蛀,贮,铸,筑,住,注,祝,驻,抓,爪,拽,专,砖,转,撰,赚,篆,桩,庄,装,妆,撞,壮,状,椎,锥,追,赘,坠,缀,谆,准,捉,拙,卓,桌,琢,茁,酌,啄,着,灼,浊,兹,咨,资,姿,滋,淄,孜,紫,仔,籽,滓,子,自,渍,字,鬃,棕,踪,宗,综,总,纵,邹,走,奏,揍,租,足,卒,族,祖,诅,阻,组,钻,纂,嘴,醉,最,罪,尊,遵,昨,左,佐,柞,做,作,坐,座";
public string CodeSerial
{
get { return codeSerial; }
set { codeSerial = value; }
}
#endregion
//产生波形滤镜效果
#region 产生波形滤镜效果
private const double PI = 3.1415926535897932384626433832795;
private const double PI2 = 6.283185307179586476925286766559;
/**/
/// <summary>
/// 正弦曲线Wave扭曲图片（Edit By 51aspx.com）
/// </summary>
/// <param name="srcBmp">图片路径</param>
/// <param name="bXDir">如果扭曲则选择为True</param>
/// <param name="nMultValue">波形的幅度倍数，越大扭曲的程度越高，一般为3</param>
/// <param name="dPhase">波形的起始相位，取值区间[0-2*PI)</param>
/// <returns></returns>
public System.Drawing.Bitmap TwistImage(Bitmap srcBmp, bool bXDir, double dMultValue, double dPhase)
{
System.Drawing.Bitmap destBmp = new Bitmap(srcBmp.Width, srcBmp.Height);
// 将位图背景填充为白色
System.Drawing.Graphics graph = System.Drawing.Graphics.FromImage(destBmp);
graph.FillRectangle(new SolidBrush(System.Drawing.Color.White), 0, 0, destBmp.Width, destBmp.Height);
graph.Dispose();
double dBaseAxisLen = bXDir ? (double) destBmp.Height : (double) destBmp.Width;
for (int i = 0; i < destBmp.Width; i++)
{
for (int j = 0; j < destBmp.Height; j++)
{
double dx = 0;
dx = bXDir ? (PI2*(double) j)/dBaseAxisLen : (PI2*(double) i)/dBaseAxisLen;
dx += dPhase;
double dy = Math.Sin(dx);
// 取得当前点的颜色
int nOldX = 0, nOldY = 0;
nOldX = bXDir ? i + (int) (dy*dMultValue) : i;
nOldY = bXDir ? j : j + (int) (dy*dMultValue);
System.Drawing.Color color = srcBmp.GetPixel(i, j);
if (nOldX >= 0 && nOldX < destBmp.Width
&& nOldY >= 0 && nOldY < destBmp.Height)
{
destBmp.SetPixel(nOldX, nOldY, color);
}
}
}
return destBmp;
}
#endregion
#region 生成校验码图片
public Bitmap CreateImageCode(string code)
{
int fSize = FontSize;
int fWidth = fSize + Padding;
int imageWidth = (int) (code.Length*fWidth) + 4 + Padding*2;
int imageHeight = fSize*2 + Padding;
System.Drawing.Bitmap image = new System.Drawing.Bitmap(imageWidth, imageHeight);
Graphics g = Graphics.FromImage(image);
g.Clear(BackgroundColor);
Random rand = new Random();
//给背景添加随机生成的燥点
if (this.Chaos)
{
Pen pen = new Pen(ChaosColor, 0);
int c = Length*10;
for (int i = 0; i < c; i++)
{
int x = rand.Next(image.Width);
int y = rand.Next(image.Height);
g.DrawRectangle(pen, x, y, 1, 1);
}
}
int left = 0, top = 0, top1 = 1, top2 = 1;
int n1 = (imageHeight - FontSize - Padding*2);
int n2 = n1/4;
top1 = n2;
top2 = n2*2;
Font f;
Brush b;
int cindex, findex;
#region 随机字体和颜色的验证码字符
for (int i = 0; i < code.Length; i++)
{
cindex = rand.Next(Colors.Length - 1);
findex = rand.Next(Fonts.Length - 1);
f = new System.Drawing.Font(Fonts[findex], fSize, System.Drawing.FontStyle.Bold);
b = new System.Drawing.SolidBrush(Colors[cindex]);
if (i%2 == 1)
{
top = top2;
}
else
{
top = top1;
}
left = i*fWidth;
g.DrawString(code.Substring(i, 1), f, b, left, top);
}
//画一个边框 边框颜色为Color.Gainsboro
g.DrawRectangle(new Pen(Color.Gainsboro, 0), 0, 0, image.Width - 1, image.Height - 1);
g.Dispose();
//产生波形
//image = TwistImage(image, true, 8, 4);
return image;
}
#endregion
//将创建好的图片输出到页面
public void CreateImageOnPage(string code, HttpContext context)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
Bitmap image = this.CreateImageCode(code);
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.ClearContent();
context.Response.ContentType = "image/Jpeg";
context.Response.BinaryWrite(ms.GetBuffer());
ms.Close();
ms = null;
image.Dispose();
image = null;
}
#endregion
#region 生成随机字符码
public string CreateVerifyCode(int codeLen)
{
if (codeLen == 0)
{
codeLen = Length;
}
string[] arr = CodeSerial.Split(',');
string code = "";
int randValue = -1;
Random rand = new Random(unchecked((int) DateTime.Now.Ticks));
for (int i = 0; i < codeLen; i++)
{
randValue = rand.Next(0, arr.Length - 1);
code += arr[randValue];
}
return code;
}
public string CreateVerifyCode()
{
return CreateVerifyCode(0);
}
#endregion
}
}到此，关于“如何使用.net生成验证码”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注亿速云网站，小编会继续努力为大家带来更多实用的文章！
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