人机交互

using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text;

using System.Windows.Forms;

namespace test_RJJH1 {

public partial class Form1 : Form {

public Form1() {

InitializeComponent(); }

int startX; int startY; Graphics g;

bool isDragging = false; Point startP; Point lastP;

private void Form1_MouseDown(object sender, MouseEventArgs e) {

startX = e.X; startY = e.Y;

isDragging = true; startP.X = e.X; startP.Y = e.Y; lastP.X = -1; lastP.Y = -1;

this.Capture = true;

}

private void Form1_Load(object sender, EventArgs e) {

this.StartPosition = FormStartPosition.CenterScreen; this.BackColor = Color.Snow; startP = new Point(); lastP = new Point();

}

private void Form1_MouseUp(object sender, MouseEventArgs e) {

g = this.CreateGraphics();

Pen p = new Pen(Color.Red, 4);

g.DrawLine(p, startX, startY, e.X, e.Y); isDragging = false ; }

private void Form1_MouseMove(object sender, MouseEventArgs e) {

if (isDragging) {

Point p1; Point p2;

if (lastP.X != -1) {

p1 = PointToScreen(startP); p2 = PointToScreen(lastP);

ControlPaint.DrawReversibleLine(p1, p2, Color.Red); }

lastP.X = e.X; lastP.Y = e.Y;

p1 = PointToScreen(startP); p2 = PointToScreen(lastP);

}

} } }

ControlPaint.DrawReversibleLine(p1, p2, Color.Red);