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C#寫的較完美驗證碼通用類

編輯：C#入門知識

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace WebApplication1.驗證碼
{
/// <summary>
/// 完美隨機驗證碼 0.10
/// Verion:0.10
/// Description:隨機生成設定驗證碼，並隨機旋轉一定角度，字體顏色不同
/// </summary>
public class ValidateCode : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
string randomcode = this.CreateRandomCode(4);
Session["ValidateCode"] = randomcode;
//ViewState["ValidateCode"] = randomcode;
this.CreateImage(randomcode);
}
/// <summary>
/// 生成隨機碼
/// </summary>
/// <param name="length">隨機碼個數</param>
/// <returns></returns>
private string CreateRandomCode(int length)
{
int rand;
char code;
string randomcode = String.Empty;
//生成一定長度的驗證碼
System.Random random = new Random();
for(int i=0;i<length;i++)
{
rand = random.Next();
if(rand%3 == 0)
{
code = (char)(A + (char)(rand%26));
}
else
{
code = (char)(0 + (char)(rand%10));
}
randomcode += code.ToString();
}
return randomcode;
}
/// <summary>
/// 創建隨機碼圖片
/// </summary>
/// <param name="randomcode">隨機碼</param>
private void CreateImage(string randomcode)
{
int randAngle = 45; //隨機轉動角度
int mapwidth = (int)(randomcode.Length * 23);
Bitmap map = new Bitmap(mapwidth,28);//創建圖片背景
Graphics graph = Graphics.FromImage(map);
graph.Clear(Color.AliceBlue);//清除畫面，填充背景
graph.DrawRectangle(new Pen(Color.Black,0),0,0,map.Width-1,map.Height-1);//畫一個邊框
//graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式
Random rand = new Random();
//背景噪點生成
Pen blackPen = new Pen(Color.LightGray,0);
for (int i=0;i<50;i++)
{
int x = rand.Next(0,map.Width);
int y = rand.Next(0,map.Height);
graph.DrawRectangle(blackPen,x,y,1,1);
}
//驗證碼旋轉，防止機器識別
char[] chars = randomcode.ToCharArray();//拆散字符串成單字符數組
//文字距中
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
//定義顏色
Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
//定義字體
string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋體" };
for(int i=0;i<chars.Length;i++)
{
int cindex = rand.Next(7);
int findex = rand.Next(5);
Font f = new System.Drawing.Font(font[findex],13,System.Drawing.FontStyle.Bold);//字體樣式(參數2為字體大小)
Brush b = new System.Drawing.SolidBrush(c[cindex]);
Point dot = new Point(16,16);
//graph.DrawString(dot.X.ToString(),fontstyle,new SolidBrush(Color.Black),10,150);//測試X坐標顯示間距的
float angle = rand.Next(-randAngle,randAngle);//轉動的度數
graph.TranslateTransform(dot.X,dot.Y);//移動光標到指定位置
graph.RotateTransform(angle);
graph.DrawString(chars[i].ToString(),f,b,1,1,format);
//graph.DrawString(chars[i].ToString(),fontstyle,new SolidBrush(Color.Blue),1,1,format);
graph.RotateTransform(-angle);//轉回去
graph.TranslateTransform(2,-dot.Y);//移動光標到指定位置
}
//graph.DrawString(randomcode,fontstyle,new SolidBrush(Color.Blue),2,2); //標准隨機碼
//生成圖片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
map.Save(ms,System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/gif";
Response.BinaryWrite(ms.ToArray());
graph.Dispose();
map.Dispose();
}
#region Web 窗體設計器生成的代碼
override protected void OnInit(EventArgs e)
{
//
// CODEGEN:&n