asp.net generate verification code (Chinese only)
- 2020-05-17 05:10:47
- OfStack
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.Text; // Add reference
using System.Drawing; // Add reference
/// <summary>
/// CheckCode_Ch Summary of
/// </summary>
public class CheckCode_Ch
{
public CheckCode_Ch()
{
//
// TODO: Add the constructor logic here
//
}
private static object[] CreateString()
{
// define 1 An array stores the constituent elements of the Chinese character encoding
string[] str = new string[16] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
Random ran = new Random(); // define 1 Random number objects
object[] bytes = new object[4];
for (int i = 0; i < 4; i++)
{
// Get location code number 1 position
int ran1 = ran.Next(11, 14);
string str1 = str[ran1].Trim();
// Get location code number 2 Bit and prevent data duplication
ran = new Random(ran1 * unchecked((int)DateTime.Now.Ticks) + i);
int ran2;
if (ran1 == 13)
{
ran2 = ran.Next(0, 7);
}
else
{
ran2 = ran.Next(0, 16);
}
string str2 = str[ran2].Trim();
// Get location code number 3 position
ran = new Random(ran2 * unchecked((int)DateTime.Now.Ticks) + i);
int ran3 = ran.Next(10, 16);
string str3 = str[ran3].Trim();
// Get location code number 4 position
ran = new Random(ran3 * unchecked((int)DateTime.Now.Ticks) + i);
int ran4;
if (ran3 == 10)
{
ran4 = ran.Next(1, 16);
}
else if (ran3 == 15)
{
ran4 = ran.Next(0, 15);
}
else
{
ran4 = ran.Next(0, 16);
}
string str4 = str[ran4].Trim();
// Define the byte variable store generated random Chinese character location code
byte byte1 = Convert.ToByte(str1 + str2, 16);
byte byte2 = Convert.ToByte(str3 + str4, 16);
byte[] stradd = new byte[] { byte1, byte2 };
// Puts the resulting Chinese character bytes into an array
bytes.SetValue(stradd, i);
}
return bytes;
}
private static string GetString()
{
Encoding gb = Encoding.GetEncoding("gb2312");
object[] bytes = CreateString();
// Chinese characters are decoded according to Chinese character bytes
string str1 = gb.GetString((byte[])Convert.ChangeType(bytes[0], typeof(byte[])));
string str2 = gb.GetString((byte[])Convert.ChangeType(bytes[1], typeof(byte[])));
string str3 = gb.GetString((byte[])Convert.ChangeType(bytes[2], typeof(byte[])));
string str4 = gb.GetString((byte[])Convert.ChangeType(bytes[3], typeof(byte[])));
string str = str1 + str2 + str3 + str4;
HttpContext.Current.Response.Cookies.Add(new HttpCookie("CheckCode", str));
return str;
}
public static void GraphicsImage()
{
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((GetString().Length * 22.5)), 22);
Graphics g = Graphics.FromImage(image); // Create a canvas
try
{
// Generative random generator
Random random = new Random();
// Empty the image background color
g.Clear(Color.White);
// Draw the background noise line of the picture
for (int i = 0; i < 1; i++)
{
int x1 = random.Next(image.Width);
int x2 = random.Next(image.Width);
int y1 = random.Next(image.Height);
int y2 = random.Next(image.Height);
g.DrawLine(new Pen(Color.Black), x1, y1, x2, y2);
}
Font font = new System.Drawing.Font("Couriew New", 12, System.Drawing.FontStyle.Bold);
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush
(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(GetString(), font, brush, 2, 2);
// Draw the foreground noise point of the picture
for (int i = 0; i < 50; i++)
{
int x = random.Next(image.Width);
int y = random.Next(image.Height);
image.SetPixel(x, y, Color.FromArgb(random.Next()));
}
// Draw the border line of the picture
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.ContentType = "image/Gif";
HttpContext.Current.Response.BinaryWrite(ms.ToArray());
}
catch (Exception ms)
{
HttpContext.Current.Response.Write(ms.Message);
}
}
}
Step 2: create a page that references the class library ChineseCheckCode.aspx.
using System;
using System.Collections;
using System.Configuration;
using System.Data;
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;
public partial class UserValidator_ChineseCheckCode : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
CheckCode_Ch.GraphicsImage(); // Call method generation 4 Bit character verification code
}
}
Step 3 refers to the captcha page
<asp:TextBox ID="Validator" runat="server" Width="150px" ></asp:TextBox>
<img id="Img1" alt=" Can't see, please click on me! " onclick="this.src=this.src+'?'" src="ChineseCheckCode.aspx"
style="width: 75px; height: 24px" align="left" />
<asp:ImageButton ID="imgBtnLogin" runat="server" ImageUrl="~/Images/Login.GIF"
OnClick="imgBtnLogin_Click" />
The background to judge
protected void imgBtnLogin_Click(object sender, ImageClickEventArgs e)
{
HttpCookie cookie = Request.Cookies["CheckCode"];
if (cookie.Value == this.Validator.Text.Trim())
{
// .
}
else
{
Response.Write("<script>alert(' Verification code input error, please re-enter! ');Location='ChineseCodeValidator.aspx'</script>");
return;
}
}
The above verification code generates 4 bits, please make appropriate modifications according to the situation.
Now it summarizes the verification code technology to generate pure Numbers, alphanumeric mixing, and pure Chinese characters. I hope it will be helpful to you.