c#ペイント検証コードの詳細

1.PictureBoxスペースを使用し、ボタンを使用して認証コードをリフレッシュします.
2.まずCheckCode()メソッドを定義し、4を英語および数字で構成する文字列シーケンスを生成します.

 
  
private string CheckCode() 
  
        { 
  
            int number; 
  
            char code; 
  
            string checkCode = String.Empty; 
  
            Random random = new Random(); 
  
            for (int i = 0; i < 4; i++) 
  
            { 
  
                number=random.Next(); 
  
                if(number%2==0) 
  
                    code=(char)('0'+(char)(number%10)); 
  
                else 
  
                    code=(char)('A'+(char)(number%26)); 
  
                checkCode += " " + code.ToString(); 
  
            } 
  
            return checkCode; 
  
        } 
  
 
 

3.CodeImage()メソッドをカスタマイズし、CheckCode()メソッドで生成されたシーケンスをピクチャに変換して表示します.

 
  
        private void CodeImage(string checkCode) 
  
        { 
  
            if (checkCode == null || checkCode.Trim() == String.Empty) 
  
            { 
  
                return; 
  
            } 
  
            System.Drawing.Bitmap image=new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length*50.0)),50); 
  
            Graphics g=Graphics.FromImage(image); 
  
            try 
  
            { 
  
                Random random = new Random(); 
  
                g.Clear(Color.White); 
  
                for (int i = 0; i < 3; 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("Arial", 30, (System.Drawing.FontStyle.Bold)); 
  
                g.DrawString(checkCode, font, new SolidBrush(Color.Red), 2, 2); 
  
                for (int i = 0; i < 200; i++) 
  
                { 
  
                    int x = random.Next(image.Width); 
  
                    int y = random.Next(image.Height); 
  
                    image.SetPixel(x, y, Color.FromArgb(random.Next())); 
  
                } 
  
                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1); 
  
                this.pictureBox1.Width = image.Width; 
  
                this.pictureBox1.Height = image.Height; 
  
                this.pictureBox1.BackgroundImage = image; 
  
            } 
  
            catch 
  
            { 
  
 
  
            } 
  
        } 
  
 
 

4.

 
  
        private void Form1_Load(object sender, EventArgs e) 
  
        { 
  
            CodeImage(CheckCode()); 
  
        } 
  
        private void button1_Click(object sender, EventArgs e) 
  
        { 
  
            CodeImage(CheckCode()); 
  
        }