欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  后端开发

asp.net生成验证码(纯数字)

程序员文章站 2024-01-21 18:01:58
...
CheckCode.cs
using System; 
using System.Data; 
using System.Configuration; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Drawing; 
/// <summary> 
/// CheckCode 的摘要说明 
/// </summary> 
public class CheckCode 
{ 
public CheckCode() 
{ 
// 
// TODO: 在此处添加构造函数逻辑 
// 
} 
public static void DrawImage() 
{ 
CheckCode img = new CheckCode(); 
HttpContext.Current.Session["CheckCode"] = img.RndNum(4); 
img.checkCodes(HttpContext.Current.Session["CheckCode"].ToString()); 
} 
/// <summary> 
/// 生成验证图片 
/// </summary> 
/// <param name="checkCode">验证字符</param> 
private void checkCodes(string checkCode) 
{ 
int iwidth = (int)(checkCode.Length * 13); 
System.Drawing.Bitmap image = new System.Drawing.Bitmap(iwidth, 23); 
Graphics g = Graphics.FromImage(image); 
g.Clear(Color.White); 
//定义颜色 
Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple }; 
//定义字体 
string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" }; 
Random rand = new Random(); 
//随机输出噪点 
for (int i = 0; i < 50; i++) 
{ 
int x = rand.Next(image.Width); 
int y = rand.Next(image.Height); 
g.DrawRectangle(new Pen(Color.LightGray, 0), x, y, 1, 1); 
} 
//输出不同字体和颜色的验证码字符 
for (int i = 0; i < checkCode.Length; i++) 
{ 
int cindex = rand.Next(7); 
int findex = rand.Next(5); 
Font f = new System.Drawing.Font(font[findex], 10, System.Drawing.FontStyle.Bold); 
Brush b = new System.Drawing.SolidBrush(c[cindex]); 
int ii = 4; 
if ((i + 1) % 2 == 0) 
{ 
ii = 2; 
} 
g.DrawString(checkCode.Substring(i, 1), f, b, 3 + (i * 12), ii); 
} 
//画一个边框 
g.DrawRectangle(new Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height - 1); 
//输出到浏览器 
System.IO.MemoryStream ms = new System.IO.MemoryStream(); 
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); 
HttpContext.Current.Response.ClearContent(); 
//Response.ClearContent(); 
HttpContext.Current.Response.ContentType = "image/Jpeg"; 
HttpContext.Current.Response.BinaryWrite(ms.ToArray()); 
g.Dispose(); 
image.Dispose(); 
} 
/// <summary> 
/// 生成随机的字母 
/// </summary> 
/// <param name="VcodeNum">生成字母的个数</param> 
/// <returns>string</returns> 
private string RndNum(int VcodeNum) 
{ 
string Vchar = "0,1,2,3,4,5,6,7,8,9"; 
string[] VcArray = Vchar.Split(','); 
string VNum = ""; //由于字符串很短,就不用StringBuilder了 
int temp = -1; //记录上次随机数值,尽量避免生产几个一样的随机数 
//采用一个简单的算法以保证生成随机数的不同 
Random rand = new Random(); 
for (int i = 1; i < VcodeNum + 1; i++) 
{ 
if (temp != -1) 
{ 
rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks)); 
} 
int t = rand.Next(VcArray.Length); 
if (temp != -1 && temp == t) 
{ 
return RndNum(VcodeNum); 
} 
temp = t; 
VNum += VcArray[t]; 
} 
return VNum; 
} 
}

再建立一个引用类的页面checkCode.aspx前台不用写东西,后台引用我们创建的类的DrawImage()方法即可。

using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
public partial class checkCode : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
CheckCode.DrawImage(); 
} 
}

下面我们在需要验证码的页面引用checkCode.aspx页面即可。
前台

<asp:TextBox ID="Validator" runat="server" Width="150px" ></asp:TextBox> 
<img id="Img1" alt="看不清,请点击我!" onclick="this.src=this.src+'?'" src="checkCode.aspx" 
style="width: 73px; height: 22px" align="left" /> 
<asp:ImageButton ID="imgBtnLogin" runat="server" ImageUrl="~/Images/Login.GIF" 
OnClick="imgBtnLogin_Click" />

后台判断

protected void imgBtnLogin_Click(object sender, ImageClickEventArgs e) 
{ 
if(this.Validator.Text==Session["CheckCode"].ToString()) 
{ 
//。。。。 
} 
else 
{ 
Response.Write("<script>alert('验证码输入错误,请重新输入!');Location='MumberValidate.aspx'</script>"); 
return; 
} 
}

以上代码请根据实际情况作适当修改。

更多asp.net生成验证码(纯数字)相关文章请关注PHP中文网!

相关标签: 验证码