画板设计之 基于图片(pictureBox)的画笔实现

首先上图吧，这是个简单的画笔(签字笔，荧光笔，排笔)的实现，实现的原理很简单，在图片上面绘制,后面我将用WPF实现个完整的画板软件，基于微软的inkcanvas,功能涵盖设计一套画笔(纹理笔，荧光笔，排笔，魔法笔，蜡笔等)，对象的加载（图片，PDF以及音视频)，对象的基本操作(拉伸，移动，旋转)以及教育画板常用的基本操作，画板的导出(IWB.XML,PDF,IMAGE). 文章的更新将是不定期的，因为这个项目是我基于目前公司正在开发的QT版白板软件，用WPF技术重构的，所以时间上是有限的。

 

主要的代码:

 客户端代码其实就是一个PictureBox控件命名为: _drawcanvas

 后台代码:

 

using  System;
using  System.Drawing;
using  System.Collections;
using  System.ComponentModel;
using  System.Windows.Forms;
using  System.Drawing.Imaging;
using  System.Drawing.Drawing2D;
using  System.IO;
using  System.Collections.Generic;

namespace  drawCanvas {
    public  partial  class  Form1 : Form {
        public  Form1() {
            InitializeComponent();

            this ._drawcanvas.MouseDown += new  MouseEventHandler(_drawcanvas_MouseDown);
            this ._drawcanvas.MouseMove += new  MouseEventHandler(_drawcanvas_MouseMove);
            this ._drawcanvas.MouseUp += new  MouseEventHandler(_drawcanvas_MouseUp);

            this ._normalPen.Click += ( object  sender, EventArgs e) => this ._penType = PenType.k_pen;
            this ._hPen.Click += ( object  sender, EventArgs e) => this ._penType = PenType.k_hight_pen;
            this ._paipen.Click += ( object  sender, EventArgs e) => this ._penType = PenType.k_pai_pen;
        }


        void  _drawcanvas_MouseUp( object  sender, MouseEventArgs e) {
            this ._isPressed = false ;
            no_of_points = 0;
        }

        void  _drawcanvas_MouseMove( object  sender, MouseEventArgs e) {
            if  (_isPressed) {
                if  (no_of_points > 3) {
                    pt[0] = pt[1]; pt[1] = pt[2]; pt[2] = pt[3];
                    pt[3].setxy(e.X, e.Y);
                    double  temp = Math.Sqrt(Math.Pow(pt[2].x - pt[1].x, 2F) + Math.Pow(pt[2].y - pt[1].y, 2F));
                    int  interpol = System.Convert.ToInt32(temp);
                    bsp(pt[0], pt[1], pt[2], pt[3], interpol);
                    int  i;
                    Graphics g = this ._drawcanvas.CreateGraphics();

                    int  x, y;

                    g.SmoothingMode = SmoothingMode.AntiAlias;  //使绘图质量最高，即消除锯齿
                    g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                    g.CompositingQuality = CompositingQuality.HighQuality;

                    for  (i = 0; i <= interpol - 1; i++) {
                        x = System.Convert.ToInt32(splinex[i]);
                        y = System.Convert.ToInt32(spliney[i]);

                        switch  (_penType) {
                            case  PenType.k_pai_pen:
                                _penColor = Color.FromArgb(255, _penColor);
                                 g.DrawLine( new  Pen(_penColor, _penWidth), new  Point(x - 1, y), new  Point(x - 1 + _x_offset, y + _y_offset));
                                 g.DrawLine( new  Pen(_penColor, _penWidth), new  Point(x + 1, y), new  Point(x + 1 + _x_offset, y + _y_offset));
                                 g.DrawLine( new  Pen(_penColor, _penWidth), new  Point(x, y - 1), new  Point(x + _x_offset, y - 1 + _y_offset));
                                 g.DrawLine( new  Pen(_penColor, _penWidth), new  Point(x, y + 1), new  Point(x + _x_offset, y + 1 + _y_offset));
                                 break ;
                            case  PenType.k_pen:
                                 _penColor = Color.FromArgb(255, _penColor);
                                 g.DrawEllipse( new  Pen(_penColor, _penWidth), x - 1, y, _penWidth , _penWidth);
                                 g.DrawEllipse( new  Pen(_penColor, _penWidth), x + 1, y, _penWidth, _penWidth);
                                 g.DrawEllipse( new  Pen(_penColor, _penWidth), x, y - 1, _penWidth, _penWidth);
                                 g.DrawEllipse( new  Pen(_penColor, _penWidth), x, y + 1, _penWidth, _penWidth);
                                 break ;
                            case  PenType.k_hight_pen:
                                 _penColor = Color.FromArgb(80, _penColor.R, _penColor.G, _penColor.B);
                                 float  p = _penWidth + 8;
                                g.DrawEllipse( new  Pen(_penColor, p), x - 1, y, _penWidth , _penWidth);
                                g.DrawEllipse( new  Pen(_penColor, p), x + 1, y, _penWidth, _penWidth);
                                g.DrawEllipse( new  Pen(_penColor, p), x, y - 1, _penWidth, _penWidth);
                                g.DrawEllipse( new  Pen(_penColor, p), x, y + 1, _penWidth, _penWidth);
                                break ;

                        }

                    }
                }
                else  {
                    pt[no_of_points].setxy(e.X, e.Y);
                }

                no_of_points = no_of_points + 1;
            }
        }

        void  _drawcanvas_MouseDown( object  sender, MouseEventArgs e) {
            _isPressed = true ;

            no_of_points = 0;
            pt[no_of_points].setxy(e.X, e.Y);
            no_of_points = no_of_points + 1;

            //Graphics g = this._drawcanvas.CreateGraphics();
            //g.DrawLine(new Pen(_penColor, _penWidth), new Point(e.X,e.Y), new Point(e.X + _x_offset, e.Y + _y_offset));
        }

        private  Color _penColor = Color.Yellow;
        private  float  _penWidth = 2;
        private  bool  _isPressed = false ;
        private  int  _x_offset = 4;
        private  int  _y_offset = 20;
        private  PenType _penType = PenType.k_pen;

        public  double [] splinex = new  double [1001];
        public  double [] spliney = new  double [1001];
        public  point[] pt = new  point[6];
        public  int  no_of_points = 0;
        int [] a1 = new  int [12];
        int [] b1 = new  int [12];

        public  struct  point {
            public  int  x;
            public  int  y;

            public  void  setxy( int  i, int  j) {
                x = i;
                y = j;
            }
        }
        // calculating the values using the algorithm
        public  void  bsp(point p1, point p2, point p3, point p4, int  divisions) {
            double [] a = new  double [5];
            double [] b = new  double [5];
            a[0] = (-p1.x + 3 * p2.x - 3 * p3.x + p4.x) / 6.0;
            a[1] = (3 * p1.x - 6 * p2.x + 3 * p3.x) / 6.0;
            a[2] = (-3 * p1.x + 3 * p3.x) / 6.0;
            a[3] = (p1.x + 4 * p2.x + p3.x) / 6.0;
            b[0] = (-p1.y + 3 * p2.y - 3 * p3.y + p4.y) / 6.0;
            b[1] = (3 * p1.y - 6 * p2.y + 3 * p3.y) / 6.0;
            b[2] = (-3 * p1.y + 3 * p3.y) / 6.0;
            b[3] = (p1.y + 4 * p2.y + p3.y) / 6.0;

            splinex[0] = a[3];
            spliney[0] = b[3];

            int  i;
            for  (i = 1; i <= divisions - 1; i++) {
                float  t = System.Convert.ToSingle(i) / System.Convert.ToSingle(divisions);
                splinex[i] = (a[2] + t * (a[1] + t * a[0])) * t + a[3];
                spliney[i] = (b[2] + t * (b[1] + t * b[0])) * t + b[3];


            }
        }

        private  void  button1_Click( object  sender, EventArgs e) {
            ColorDialog dlg = new  ColorDialog();
            if  (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK) {
                _penColor = dlg.Color;
            }
        }

    }

    public  enum  PenType {
        k_pen = 0x1,
        k_hight_pen = 0x2,
        k_pai_pen
    }
}

　　

 demo下载