(C#加密)幻术-大踲无形

首先:我看下面的代码只是知道大概的原理核心算法还是不太清楚~~有清楚的麻烦回复下谢谢咯咯
--这也是看Msdn就是把在一个图片上隐藏数据

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

using System.Text; 

namespace Steganography
{
    /**//// <summary>
    /// Summary description for SteganographyForm.
    /// </summary>
    public class SteganographyForm : System.Windows.Forms.Form
    {
        private System.Windows.Forms.Button buttonHideMessage;
        private System.Windows.Forms.Panel panelOriginalImage;
        private System.Windows.Forms.TextBox textBoxOriginalMessage;
        private System.Windows.Forms.Panel panelModifiedImage;
        private System.Windows.Forms.GroupBox groupBox1;
        private System.Windows.Forms.GroupBox groupBox3;
        private System.Windows.Forms.GroupBox groupBox4;
        private System.Windows.Forms.Button buttonExtractMessage;
        private System.Windows.Forms.TextBox textBoxExtractedlMessage;
        private System.Windows.Forms.GroupBox groupBox2;

        /**//// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;

        public SteganographyForm()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();

            //
            // TODO: Add any constructor code after InitializeComponent call
            //
            try
            {
                //load original bitmap from a file
                bitmapOriginal = (Bitmap)Bitmap.FromFile(
                    @"..\..\katie_plaintext.jpg");

                //center to screen
                this.CenterToScreen( );
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "Error loading image. " + 
                    ex.Message );
            }
        }

        /**//// <summary>
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        Windows Form Designer generated code#region Windows Form Designer generated code
        /**//// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.buttonHideMessage = new System.Windows.Forms.Button();
            this.panelOriginalImage = new System.Windows.Forms.Panel();
            this.textBoxOriginalMessage = new System.Windows.Forms.TextBox();
            this.panelModifiedImage = new System.Windows.Forms.Panel();
            this.groupBox1 = new System.Windows.Forms.GroupBox();
            this.groupBox3 = new System.Windows.Forms.GroupBox();
            this.groupBox4 = new System.Windows.Forms.GroupBox();
            this.buttonExtractMessage = new System.Windows.Forms.Button();
            this.textBoxExtractedlMessage = new System.Windows.Forms.TextBox();
            this.groupBox2 = new System.Windows.Forms.GroupBox();
            this.SuspendLayout();
            // 
            // buttonHideMessage
            // 
            this.buttonHideMessage.Location = new System.Drawing.Point(10, 594);
            this.buttonHideMessage.Name = "buttonHideMessage";
            this.buttonHideMessage.Size = new System.Drawing.Size(144, 25);
            this.buttonHideMessage.TabIndex = 0;
            this.buttonHideMessage.Text = "Hide Message";
            this.buttonHideMessage.Click += new System.EventHandler(this.buttonHideMessage_Click);
            // 
            // panelOriginalImage
            // 
            this.panelOriginalImage.Location = new System.Drawing.Point(19, 26);
            this.panelOriginalImage.Name = "panelOriginalImage";
            this.panelOriginalImage.Size = new System.Drawing.Size(412, 521);
            this.panelOriginalImage.TabIndex = 0;
            // 
            // textBoxOriginalMessage
            // 
            this.textBoxOriginalMessage.Location = new System.Drawing.Point(182, 594);
            this.textBoxOriginalMessage.Name = "textBoxOriginalMessage";
            this.textBoxOriginalMessage.Size = new System.Drawing.Size(240, 21);
            this.textBoxOriginalMessage.TabIndex = 1;
            // 
            // panelModifiedImage
            // 
            this.panelModifiedImage.Location = new System.Drawing.Point(461, 26);
            this.panelModifiedImage.Name = "panelModifiedImage";
            this.panelModifiedImage.Size = new System.Drawing.Size(411, 521);
            this.panelModifiedImage.TabIndex = 0;
            // 
            // groupBox1
            // 
            this.groupBox1.Location = new System.Drawing.Point(163, 569);
            this.groupBox1.Name = "groupBox1";
            this.groupBox1.Size = new System.Drawing.Size(279, 60);
            this.groupBox1.TabIndex = 3;
            this.groupBox1.TabStop = false;
            this.groupBox1.Text = "Original Message";
            // 
            // groupBox3
            // 
            this.groupBox3.Location = new System.Drawing.Point(10, 9);
            this.groupBox3.Name = "groupBox3";
            this.groupBox3.Size = new System.Drawing.Size(432, 551);
            this.groupBox3.TabIndex = 3;
            this.groupBox3.TabStop = false;
            this.groupBox3.Text = "Original Image";
            // 
            // groupBox4
            // 
            this.groupBox4.Location = new System.Drawing.Point(451, 9);
            this.groupBox4.Name = "groupBox4";
            this.groupBox4.Size = new System.Drawing.Size(432, 551);
            this.groupBox4.TabIndex = 3;
            this.groupBox4.TabStop = false;
            this.groupBox4.Text = "Modified Image";
            // 
            // buttonExtractMessage
            // 
            this.buttonExtractMessage.Location = new System.Drawing.Point(451, 594);
            this.buttonExtractMessage.Name = "buttonExtractMessage";
            this.buttonExtractMessage.Size = new System.Drawing.Size(144, 25);
            this.buttonExtractMessage.TabIndex = 2;
            this.buttonExtractMessage.Text = "Extract Message";
            this.buttonExtractMessage.Click += new System.EventHandler(this.buttonExtractMessage_Click);
            // 
            // textBoxExtractedlMessage
            // 
            this.textBoxExtractedlMessage.Location = new System.Drawing.Point(624, 594);
            this.textBoxExtractedlMessage.Name = "textBoxExtractedlMessage";
            this.textBoxExtractedlMessage.ReadOnly = true;
            this.textBoxExtractedlMessage.Size = new System.Drawing.Size(240, 21);
            this.textBoxExtractedlMessage.TabIndex = 3;
            // 
            // groupBox2
            // 
            this.groupBox2.Location = new System.Drawing.Point(605, 569);
            this.groupBox2.Name = "groupBox2";
            this.groupBox2.Size = new System.Drawing.Size(278, 60);
            this.groupBox2.TabIndex = 3;
            this.groupBox2.TabStop = false;
            this.groupBox2.Text = "Extractedl Message";
            // 
            // SteganographyForm
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.ClientSize = new System.Drawing.Size(930, 672);
            this.Controls.Add(this.textBoxOriginalMessage);
            this.Controls.Add(this.buttonHideMessage);
            this.Controls.Add(this.panelModifiedImage);
            this.Controls.Add(this.groupBox1);
            this.Controls.Add(this.panelOriginalImage);
            this.Controls.Add(this.groupBox3);
            this.Controls.Add(this.groupBox4);
            this.Controls.Add(this.buttonExtractMessage);
            this.Controls.Add(this.textBoxExtractedlMessage);
            this.Controls.Add(this.groupBox2);
            this.Name = "SteganographyForm";
            this.Text = "Steganography";
            this.Paint += new System.Windows.Forms.PaintEventHandler(this.SteganographyForm_Paint);
            this.ResumeLayout(false);
            this.PerformLayout();

        }
        #endregion

        /**//// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new SteganographyForm());
        }

        private void SteganographyForm_Paint(
            object sender, 
            System.Windows.Forms.PaintEventArgs e)
        {
            try
            {
                //get Graphics object for painting original
                Graphics gPanelOriginal = 
                    Graphics.FromHwnd(
                        panelOriginalImage.Handle);

                //draw original bitmap into panel
                gPanelOriginal.DrawImage(
                    bitmapOriginal, new Point(0 ,0));

                //return if there is no modified image yet
                if (bitmapModified==null)
                    return;

                //get Graphics object for painting modified
                Graphics gPanelModified = 
                    Graphics.FromHwnd(
                        panelModifiedImage.Handle);

                //draw modified bitmap into panel
                gPanelModified.DrawImage(
                    bitmapModified, new Point(0 ,0));
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "Error drawing image." +
                    ex.Message);
                this.Close( );
            }
        }

        private void buttonHideMessage_Click(
            object sender, System.EventArgs e)
        {
            try
            {
                //show wait cursor
                this.Cursor = Cursors.WaitCursor;

                //start off with copy of original image
                bitmapModified = new Bitmap(
                    bitmapOriginal, 
                    bitmapOriginal.Width, 
                    bitmapOriginal.Height);

                //get original message to be hidden
                int numberbytes = 
                    (byte)textBoxOriginalMessage.Text.Length;
                byte[] bytesOriginal = new byte[numberbytes+1];
                bytesOriginal[0] = (byte)numberbytes;
                Encoding.UTF8.GetBytes(
                    textBoxOriginalMessage.Text,
                    0,
                    textBoxOriginalMessage.Text.Length,
                    bytesOriginal,
                    1);

                //set bits 1, 2, 3 of byte into LSB red
                //set bits 4, 5, 6 of byte into LSB green
                //set bits 7 and 8 of byte into LSB blue
                int byteCount = 0;//----一列一列搞定
                for (int i=0; i<bitmapOriginal.Width; i++)
                {
                    for (int j=0; j<bitmapOriginal.Height; j++)
                    {
                        if (bytesOriginal.Length==byteCount)
                            return;
                        //---返回当前循环的坐标点的颜色数据
                        Color clrPixelOriginal = 
                            bitmapOriginal.GetPixel(i, j);
                        //为基元整型类型、枚举类型和 boolean 类型预定义了二元 | 运算符。对于基元整型类型和枚举类型，| 计算操作数的按位“或”。
                        //--注意这里是对~~血迹之术-的实际应用中的变种
                        //--这里的算法还是不太清楚估计是-防止三元素重合成1点后产生的错位--如果大大们知道麻烦告诉我下
                        byte r = 
                            (byte)((clrPixelOriginal.R & ~0x7) |
                            (bytesOriginal[byteCount]>>0)&0x7);
                        byte g = 
                            (byte)((clrPixelOriginal.G & ~0x7) |
                            (bytesOriginal[byteCount]>>3)&0x7);
                        byte b = 
                            (byte)((clrPixelOriginal.B & ~0x3) |
                            (bytesOriginal[byteCount]>>6)&0x3);
                        byteCount++;

                        //set pixel to modified color
                        bitmapModified.SetPixel(
                            i, j, Color.FromArgb(r, g, b));
                    }

                   
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "Error hiding message." +
                    ex.Message);
            }
            finally
            {
                //show normal cursor
                this.Cursor = Cursors.Arrow;

                //repaint
                Invalidate();
            }
        }

        private void buttonExtractMessage_Click(
            object sender, System.EventArgs e)
        {
            //get bytes of message from modified image
            byte[] bytesExtracted = new byte [256+1];
            try
            {
                //show wait cursor, can be time-consuming
                this.Cursor = Cursors.WaitCursor;
                
                //get bits 1, 2, 3 of byte from LSB red
                //get bits 4, 5, 6 of byte from LSB green
                //get bits 7 and 8 of byte from LSB blue
                int byteCount = 0;
                for (int i=0; i<bitmapModified.Width; i++)
                {
                    for (int j=0; j<bitmapModified.Height; j++)
                    {
                        if (bytesExtracted.Length==byteCount)
                            return;

                        Color clrPixelModified = 
                            bitmapModified.GetPixel(i, j);
                        byte bits123 = 
                            (byte)((clrPixelModified.R&0x7)<<0);
                        byte bits456 = (
                            byte)((clrPixelModified.G&0x7)<<3);
                        byte bits78  = (
                            byte)((clrPixelModified.B&0x3)<<6);
                    
                        bytesExtracted[byteCount] = 
                            (byte)(bits78 |bits456 | bits123);
                        byteCount++;
                    }

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(
                    "Error extracting message." +
                    ex.Message);
            }
            finally
            {
                //show normal cursor
                this.Cursor = Cursors.Arrow;

                //get number of bytes from start of array
                int numberbytes = bytesExtracted[0];

                //get remaining bytes in array into string
                textBoxExtractedlMessage.Text =  
                    Encoding.UTF8.GetString(
                    bytesExtracted,
                    1,
                    numberbytes);
            }        
        }

        //shared private fields
        private Bitmap bitmapOriginal;
        private Bitmap bitmapModified;
    }
}