驗證碼 － C＃winForm格式

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; namespace validateCode { public partial class Login : Form { //隨機碼的長度 private const int CODELENGTH = 6; //隨機碼 private String randomCode = ""; //隨機碼對應的圖片 public Login() { InitializeComponent(); updatePic(); } //更新驗證碼 private void updatePic() { randomCode = CreateRandomCode(CODELENGTH); CreateImage(randomCode); } private string CreateRandomCode(int length) { int rand; char code; string randomCode = String.Empty; //產生一定長度的驗證碼 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; } /// 建立隨機碼圖片 private void CreateImage(string randomCode) { try { int randAngle = 45; //隨機轉動角度 int mapwidth = (int)(randomCode.Length * 21); Bitmap map = new Bitmap(mapwidth, 28);//建立圖片背景 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(); //背景噪點產生 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();//拆散字串成單字元數組 //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 }; //定義字型 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);//字型樣式(參數2為字型大小) Brush b = new System.Drawing.SolidBrush(c[cindex]); Point dot = new Point(16, 16); float angle = rand.Next(-randAngle, randAngle);//轉動的度數 graph.TranslateTransform(dot.X, dot.Y);//移動游標到指定位置 graph.RotateTransform(angle); graph.DrawString(chars[i].ToString(), f, b, 1, 1, format); graph.RotateTransform(-angle);//轉回去 graph.TranslateTransform(2, -dot.Y);//移動游標到指定位置 } pbVerifyCode.Image = map; } catch (ArgumentException) { MessageBox.Show("建立圖片錯誤。"); } } private void btLogin_Click(object sender, EventArgs e) { if (randomCode.Equals(tbVerifyCode.Text.Trim())) { if (tbUserName.Text.Trim().Equals("stdManager") && tbPassword.Text.Trim().Equals("stdManager")) { MessageBox.Show("歡迎使用線上書城管理系統。"); } } else { MessageBox.Show("驗證碼錯誤,請重新輸入.","輸入錯誤"); updatePic(); tbVerifyCode.Text = ""; tbVerifyCode.Focus(); } } private void pbVerifyCode_Click(object sender, EventArgs e) { updatePic(); } private void btExit_Click(object sender, EventArgs e) { if (MessageBox.Show("確定退出嗎?", "退出", MessageBoxButtons.OKCancel, MessageBoxIcon.Exclamation) == DialogResult.OK) { Application.Exit(); } } } }