结果如图所示：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 交互式绘图1
{
enum GraphType
{ empty, free, line, rectangle,ellipse,polygon,bezier,closedcurve}
public partial class Form1 : Form
{
Bitmap myBitmap;
Graphics myGraphics,myPicGraphics;
GraphType myGraphType;
Pen myPen, myTrackPen, myOutlinePen;
bool startDraw=false;
Point startPt, PrevPt, P2, P3, EndPt;
Point TrackPt;
int besizerPtNum;
List<Point> myCurvePts = new List<Point>();
public Form1()
{
InitializeComponent();
myBitmap = new Bitmap(pictureBox1.Width, pictureBox1.Height);
myGraphics = Graphics.FromImage(myBitmap);
myPicGraphics = this.pictureBox1.CreateGraphics();
myGraphType = GraphType.empty;
myPen = new Pen(Color.Black, 3);
myTrackPen = new Pen(myPen.Color, myPen.Width);
myTrackPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dot;
myOutlinePen = new Pen(Color.Red, 1);
myOutlinePen.DashStyle = DashStyle.Dash;
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
//myGraphics.DrawRectangle(Pens.Red, e.X - 1, e.Y - 1, 3, 3);
if (myGraphType == GraphType.free)
{
startDraw = true;
startPt = e.Location;
}
if (myGraphType == GraphType.line)
{
startDraw = true;
startPt = e.Location;
TrackPt = startPt;
}
if (myGraphType == GraphType.rectangle)
{
startDraw = true;
startPt = e.Location;
TrackPt = startPt;
}
if (myGraphType == GraphType.ellipse)
{
startDraw = true;
startPt = e.Location;
TrackPt = startPt;
}
if (myGraphType == GraphType.polygon)
{
if (startDraw == false)
{
startDraw = true;
startPt = e.Location;
TrackPt = startPt;
PrevPt = startPt;
}
else
{
if (e.Clicks == 1)
{
myGraphics.DrawLine(myPen, PrevPt, e.Location);
PrevPt = e.Location;
}
if (e.Clicks == 2)
{
startDraw = false;
myGraphics.DrawLine(myPen, e.Location,startPt );
}
}
}
if (myGraphType == GraphType.bezier)
{
if (startDraw == false)
{
startDraw = true;
startPt = e.Location;
TrackPt = startPt;
PrevPt = startPt;
besizerPtNum = 1;
}
else
{
if (e.Clicks == 1)
{
if (besizerPtNum == 1)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myGraphics.DrawLine(myOutlinePen, startPt, e.Location);
P2 = e.Location;
PrevPt = P2;
TrackPt = P2;
besizerPtNum = 2;
}
else if (besizerPtNum == 2)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myGraphics.DrawLine(myOutlinePen, P2, e.Location);
P3 = e.Location;
PrevPt = P3;
TrackPt = P3;
besizerPtNum = 3;
}
else if (besizerPtNum == 3)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myGraphics.DrawLine(myOutlinePen, P3, e.Location);
EndPt = e.Location;
myGraphics.DrawBezier(myPen, startPt, P2, P3, EndPt);
besizerPtNum = 1;
startPt = EndPt;
PrevPt = startPt;
TrackPt = startPt;
}
}
if (e.Clicks == 2)
{
startDraw = false;
}
}
}
if (myGraphType == GraphType.closedcurve)
{
if (startDraw == false)
{
startDraw = true;
//myCurvePts.Clear();
myCurvePts.Add(e.Location);
PrevPt = e.Location;
TrackPt = e.Location;
}
else
{
if (e.Clicks == 1)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myGraphics.DrawLine(myOutlinePen, PrevPt, e.Location);
myCurvePts.Add(e.Location);
PrevPt = e.Location;
TrackPt = e.Location;
}
if (e.Clicks == 2)
{
startDraw = false;
myGraphics.DrawClosedCurve(myPen, myCurvePts.ToArray());
//myGraphics.DrawCurve(myPen, myCurvePts.ToArray());
myCurvePts.Clear();
}
}
}
myPicGraphics.DrawImage(myBitmap, 0, 0);
}
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (startDraw)
{
if (myGraphType == GraphType.closedcurve)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myTrackPen.Color = myPen.Color;
myPicGraphics.DrawLine(myTrackPen, PrevPt, e.Location);
TrackPt = e.Location;
}
if (myGraphType == GraphType.bezier)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myTrackPen.Color = myPen.Color;
myPicGraphics.DrawLine(myTrackPen, PrevPt, e.Location);
TrackPt = e.Location;
}
if (myGraphType == GraphType.polygon)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, PrevPt, TrackPt);
myTrackPen.Color = myPen.Color;
myPicGraphics.DrawLine(myTrackPen, PrevPt, e.Location);
TrackPt = e.Location;
}
if (myGraphType == GraphType.free)
{
myGraphics.DrawLine(myPen, startPt, e.Location);
startPt = e.Location;
}
if (myGraphType == GraphType.line)
{
myTrackPen.Color = pictureBox1.BackColor;
myPicGraphics.DrawLine(myTrackPen, startPt, TrackPt);
myTrackPen.Color = myPen.Color;
myPicGraphics.DrawLine(myTrackPen, startPt, e.Location);
TrackPt = e.Location;
}
if (myGraphType == GraphType.rectangle)
{
myTrackPen.Color = pictureBox1.BackColor;
if (startPt.X <= TrackPt.X && startPt.Y <= TrackPt.Y)
myPicGraphics.DrawRectangle(myTrackPen, startPt.X, startPt.Y,
Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
if(startPt.X <= TrackPt.X && startPt.Y > TrackPt.Y)
myPicGraphics.DrawRectangle(myTrackPen, startPt.X, TrackPt.Y,
Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
if (startPt.X > TrackPt.X && startPt.Y <= TrackPt.Y)
myPicGraphics.DrawRectangle(myTrackPen, TrackPt.X, startPt.Y,
Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
if (startPt.X > TrackPt.X && startPt.Y > TrackPt.Y)
myPicGraphics.DrawRectangle(myTrackPen, TrackPt.X, TrackPt.Y,
Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
myTrackPen.Color = myPen.Color;
if (startPt.X <= e.X && startPt.Y <= e.Y)
myPicGraphics.DrawRectangle(myTrackPen, startPt.X, startPt.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X <= e.X && startPt.Y > e.Y)
myPicGraphics.DrawRectangle(myTrackPen, startPt.X, e.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X > e.X && startPt.Y <= e.Y)
myPicGraphics.DrawRectangle(myTrackPen, e.X, startPt.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X > e.X && startPt.Y > e.Y)
myPicGraphics.DrawRectangle(myTrackPen, e.X, e.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
TrackPt = e.Location;
}
//if (myGraphType == GraphType.ellipse)
//{
// myTrackPen.Color = pictureBox1.BackColor;
// if (startPt.X <= TrackPt.X && startPt.Y <= TrackPt.Y)
// myPicGraphics.DrawEllipse(myTrackPen, startPt.X, startPt.Y,
// Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
// if (startPt.X <= TrackPt.X && startPt.Y > TrackPt.Y)
// myPicGraphics.DrawEllipse(myTrackPen, startPt.X, TrackPt.Y,
// Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
// if (startPt.X > TrackPt.X && startPt.Y <= TrackPt.Y)
// myPicGraphics.DrawEllipse(myTrackPen, TrackPt.X, startPt.Y,
// Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
// if (startPt.X > TrackPt.X && startPt.Y > TrackPt.Y)
// myPicGraphics.DrawEllipse(myTrackPen, TrackPt.X, TrackPt.Y,
// Math.Abs(TrackPt.X - startPt.X), Math.Abs(TrackPt.Y - startPt.Y));
// myTrackPen.Color = myPen.Color;
// if (startPt.X <= e.X && startPt.Y <= e.Y)
// myPicGraphics.DrawEllipse(myTrackPen, startPt.X, startPt.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X <= e.X && startPt.Y > e.Y)
// myPicGraphics.DrawEllipse(myTrackPen, startPt.X, e.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X > e.X && startPt.Y <= e.Y)
// myPicGraphics.DrawEllipse(myTrackPen, e.X, startPt.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X > e.X && startPt.Y > e.Y)
// myPicGraphics.DrawEllipse(myTrackPen, e.X, e.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// TrackPt = e.Location;
//}
myPicGraphics.DrawImage(myBitmap, 0,0);
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
if (myGraphType == GraphType.free)
{
startDraw = false;
}
if (myGraphType == GraphType.line)
{
startDraw = false;
EndPt = e.Location;
myGraphics.DrawLine(myPen, startPt, EndPt);
}
if (myGraphType == GraphType.rectangle)
{
startDraw = false;
if (startPt.X <= e.X && startPt.Y <= e.Y)
myGraphics.DrawRectangle(myPen, startPt.X, startPt.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X <= e.X && startPt.Y > e.Y)
myGraphics.DrawRectangle(myPen, startPt.X, e.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X > e.X && startPt.Y <= e.Y)
myGraphics.DrawRectangle(myPen, e.X, startPt.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
if (startPt.X > e.X && startPt.Y > e.Y)
myGraphics.DrawRectangle(myPen, e.X, e.Y,
Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
}
//if (myGraphType == GraphType.ellipse)
//{
// startDraw = false;
// if (startPt.X <= e.X && startPt.Y <= e.Y)
// myGraphics.DrawEllipse(myPen, startPt.X, startPt.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X <= e.X && startPt.Y > e.Y)
// myGraphics.DrawEllipse(myPen, startPt.X, e.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X > e.X && startPt.Y <= e.Y)
// myGraphics.DrawEllipse(myPen, e.X, startPt.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
// if (startPt.X > e.X && startPt.Y > e.Y)
// myGraphics.DrawEllipse(myPen, e.X, e.Y,
// Math.Abs(e.X - startPt.X), Math.Abs(e.Y - startPt.Y));
//}
myPicGraphics.DrawImage(myBitmap, 0, 0);
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawImage(myBitmap, 0, 0);
}
private void 自由画线ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.free;
}
private void 直线ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.line;
}
private void 矩形ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.rectangle;
}
private void 椭圆ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.ellipse;
}
private void 多边形ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.polygon;
}
private void bezier曲线ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.bezier;
}
private void 闭合曲线ToolStripMenuItem_Click(object sender, EventArgs e)
{
myGraphType = GraphType.closedcurve;
}
}
}