页面
using System; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Drawing; namespace AMPlatForm.Union.Online { public partial class ValiCode : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { DoImg(DoCode(5)); } /// <summary> /// 生成验证码表达式 /// </summary> /// <param name="num">验证码的长度</param> /// <returns>验证码表达式</returns> private string DoCode(int num) { //要从这个数组中随机取字符来生成验证码 string[] Codesource ={"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 code = ""; Random rd = new Random(); for (int i = 0; i < num; i++) { code += Codesource[rd.Next(0, Codesource.Length)]; } return code; } /// <summary> /// 生成图片 /// </summary> /// <param name="code">验证码表达式</param> private void DoImg(string code) { Random random = new Random(); Bitmap mypalette = new Bitmap(100, 30); Graphics gh = Graphics.FromImage(mypalette); using (gh) { Rectangle rc = new Rectangle(0, 0, 100, 30); //填充图片 gh.FillRectangle(new SolidBrush(Color.White), rc); for (int i = 0; i < 1; i++) { int x1 = random.Next(mypalette.Width); int x2 = random.Next(mypalette.Width); int y1 = random.Next(mypalette.Height); int y2 = random.Next(mypalette.Height); //在图片上随机画线条 gh.DrawLine(new Pen(Color.Blue), x1, y1, x2, y2); } gh.DrawString(code, new Font("宋体", 20), new SolidBrush(Color.Black), rc); for (int i = 1; i < 60; i++) { int x = random.Next(mypalette.Width); int y = random.Next(mypalette.Height); //在图片中填充随机颜色 mypalette.SetPixel(x, y, Color.FromArgb(random.Next())); } //将生成的图像保存到流中 mypalette.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); Session["ValiCode"] = code; //主要用来验证 } Response.Write(code); } } }
前端局部刷新
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm3.aspx.cs" Inherits="Test.WebForm3" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <fieldset> <legend>验证码测试</legend>请输入验证码：<asp:TextBox ID="valid" runat="server"></asp:TextBox> <img id="img" alt="" src="ValiCode.aspx" /> <a href="javascript:;" id="aImg">刷新验证码</a> <asp:Button ID="Button1" runat="server" Text="提交" onclick="Button1_Click" /> </fieldset> </div> </form> <script type="text/javascript" > var img = document.getElementById("img"); var alink = document.getElementById("aImg"); alink.onclick = function () { // img.setAttribute("src", "ValiCode.aspx?temp="+ (new Date().getTime().toString(36))); img.setAttribute("src", "ValiCode.aspx?temp=" + Math.ceil(Math.random()*1000)); } </script> </body> </html>
注意加参数
图片自己刷新
<body>
<form id="form1" runat="server">
<div>
<fieldset>
<legend>验证码测试</legend>请输入验证码：<asp:TextBox ID="valid" runat="server"></asp:TextBox>
<img id="img" style="cursor:pointer;" src="ValiCode.aspx" />
<asp:Button ID="Button1" runat="server" Text="提交" onclick="Button1_Click" />
</fieldset>
</div>
</form>
<script type="text/javascript" >
var img = document.getElementById("img");
img.onclick = function () {
// img.setAttribute("src", "ValiCode.aspx?temp="+ (new Date().getTime().toString(36)));
img.setAttribute("src", "ValiCode.aspx?temp=" + Math.ceil(Math.random() * 1000));
}
</script>
</body>