我正在尝试创建一个记录鼠标点击的程序，在这些点之间绘制线条，并在一些计算后通过按钮调用显示一些圆圈。我的问题是我可以显示线条或圆圈，但不能同时显示两者。
我知道有些东西重叠了，但我对Java很新，我不知道如何修复它。这是代码：
package fempack;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import java.lang.Math;
public class MainFem extends JPanel {
final DrawPoints Npoints = new DrawPoints();
final DrawLines Nline = new DrawLines();
private static final long serialVersionUID = 1L;
private MouseHandler mouseHandler = new MouseHandler();
private Point p1 = new Point(100, 100);
public int Xpoint[][] = new int[500][30];
public int Ypoint[][] = new int[500][30];
private double Xmpoint[][] = new double[500][1000]; // [i γραμμή][συντεταγμένη Χ]
private double Ympoint[][] = new double[500][1000];
private double Vec[][][] = new double[500][2][500]; // [i γραμμή][0,1][0α 1β]
private double dist[] = new double[10000];
private boolean drawing;
private int c1;
private int c2;
public MainFem() {
this.addMouseListener(mouseHandler);
this.addMouseMotionListener(mouseHandler);
}
// -------------- Draw by clicking -----------------------
private class MouseHandler extends MouseAdapter {
@Override
public void mousePressed(MouseEvent e) {
if(SwingUtilities.isRightMouseButton(e)){
drawing=false;
c2++;
}
if(SwingUtilities.isLeftMouseButton(e)){
p1 = e.getPoint();
Xpoint[c1][c2] = p1.x;
Ypoint[c1][c2] = p1.y;
if (c1 > 3) {
for (int j = 0; j<c2+1; j++){
for (int i = 0; i<c1; i++){
if ((Math.abs(Xpoint[i][j]-Xpoint[c1][c2]) < 10) && (Math.abs(Ypoint[i][j]-Ypoint[c1][c2]) < 10)) {
Xpoint[c1][c2] = Xpoint[i][j];
Ypoint[c1][c2] = Ypoint[i][j];
System.out.println(Xpoint[i][j]);
}
}
}
}
if (drawing == true){
Nline.addLine(Xpoint[c1][c2], Ypoint[c1][c2], Xpoint[c1-1][c2], Ypoint[c1-1][c2]);
}
c1++;
drawing = true;
}
}
}
// ---------------- Create Mesh Points --------------------------
public void createmesh() {
int mdi = 0;
for (int j = 0; j<=c2; j++){
for (int i = 0; i<c1-1; i++){
// Υπολογισμός a και b συνιστωσών της εξίσωσης της γραμμής
Vec[i][0][mdi] = (Ypoint[i+1][j] - Ypoint[i][j])/(Xpoint[i+1][j] - Xpoint[i][j]);
Vec[i][1][mdi] = Ypoint[i][j] - Xpoint[i][j]*Vec[i][1][mdi];
// Υπολογισμός μέτρου διανύσματος
dist[mdi] = Math.sqrt(Math.pow(Xpoint[i][j] - Xpoint[i+1][j], 2) + Math.pow(Ypoint[i][j] - Ypoint[i+1][j], 2) );
// Υπολογισμός ενδιάμεσον σημείων
int nkom = 3;
double xa = Xpoint[i][j];
double ya = Ypoint[i][j];
for (int ii = 0; ii <nkom; ii++) {
double a = Vec[i][0][mdi];
double b = Vec[i][1][mdi];
Xmpoint[i][ii] = (-((2*a)*(b - ya) - 2*xa) + Math.sqrt(Math.abs(Math.pow(((2*a)*(b - ya) - 2*xa), 2) - 4*(1 + a*a)*(xa*xa + Math.pow((b - ya),2) - Math.pow(dist[mdi]/nkom,2)))))/(2 + 2*a*a);
Ympoint[i][ii] = a*Xmpoint[i][ii] + b;
double xm11 = Xmpoint[i][ii];
double ym11 = Ympoint[i][ii];
int xm1 = (int) xm11;
int ym1 = (int) ym11;
Npoints.addPoint(xm1, ym1);
System.out.println("i:" + ym11 + "...ii:" + ym1 );
xa = Xmpoint[i][ii];
ya = Ympoint[i][ii];
}
mdi++;
}
}
}
//------------------------- Display ---------------------------
private void display() {
JFrame f = new JFrame("LinePanel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setPreferredSize(new Dimension(500, 600));
f.setLocationRelativeTo(null);
f.add(Npoints);
f.add(Nline);
JPanel buttonsPanel = new JPanel();
//-----------------Complete---------------
JButton dcomp = new JButton("Complete");
buttonsPanel.add(dcomp);
dcomp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
createmesh();
}
});
//------------------Clean-------------------
JButton clearButton = new JButton("Clear");
buttonsPanel.setBorder(BorderFactory.createLineBorder(Color.black));
buttonsPanel.setPreferredSize(new Dimension(500, 100));
f.add(buttonsPanel, BorderLayout.SOUTH);
buttonsPanel.add(clearButton);
clearButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Nline.clearLines();
}
});
f.pack();
f.setVisible(true);
f.add(this);
}
//---------------------------------------------------------
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new MainFem().display();
}
});
}
}
绘制线条的类：
package fempack;
import java.awt.Graphics;
import java.util.LinkedList;
import javax.swing.JPanel;
public class DrawLines extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
public DrawLines() {
}
private static class Line{
final int x1;
final int y1;
final int x2;
final int y2;
public Line(int x1, int y1, int x2, int y2) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
}
private final LinkedList<Line> lines = new LinkedList<Line>();
public void addLine(int x1, int x2, int x3, int x4) {
lines.add(new Line(x1,x2,x3,x4));
repaint();
}
public void clearLines() {
lines.clear();
repaint();
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Line line : lines) {
// System.out.println(line);
g.drawLine(line.x1, line.y1, line.x2, line.y2);
}
}
}
绘制圆圈的课程：
package fempack;
import java.awt.Graphics;
import javax.swing.JPanel;
import java.util.LinkedList;
public class DrawPoints extends JPanel {
private static final long serialVersionUID = 1L;
public DrawPoints() {
}
private static class Point {
final int x;
final int y;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
}
private final LinkedList<Point> points = new LinkedList<Point>();
public void addPoint(int x, int y) {
points.add(new Point(x,y));
// System.out.println(x);
repaint();
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Point point : points) {
// System.out.println(point);
g.drawOval(point.x, point.y, 5, 5);
}
}
}
答案 0 :(得分：0)
这是我在createmesh（）中添加点的解决方案。我没有修改你从鼠标位置得到的点的任何处理。我只是试图重构和清理你的代码。
现在DrawLine和DrawPoint不再是JPanel，它们只是保存你给它们的数据并绘制到你在public void draw(Graphics g)方法中传递给它们的Graphics-Object，它在DrawPanel-Class中的paint上调用。 DrawPanel继承自JPanel并覆盖void PaintComponent(Graphics g);来实现这一点（感谢MadProgrammer;）。 DrawPanel还使用MouseEvents将鼠标位置放入DrawLines-和DrawPoints-对象中。
MainWindow继承自JFrame并且是MainWindow。它创建所有GUI元素，并在必要时调用DrawPanel。
主窗口：
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class MainWindow extends JFrame {
private static final long serialVersionUID = 6755417048009930291L;
// begin gui components
JButton clearButton = null;
JButton dcomp = null;
JPanel buttonsPanel = null;
DrawPanel drawPanel = null;
// end gui components
public MainWindow(){
// Add ButtonPanel
add(getDrawPanel(), BorderLayout.CENTER);
add(getButtonPanel(), BorderLayout.SOUTH);
// Add Buttons
getButtonPanel().add(getDcomp());
getButtonPanel().add(getClearButton());
addMouseListener(getDrawPanel());
}
// begin getters and setters for gui components
private DrawPanel getDrawPanel(){
if(drawPanel == null){
drawPanel = new DrawPanel();
drawPanel.setVisible(true);
}
return drawPanel;
}
private JPanel getButtonPanel() {
if(buttonsPanel == null){
buttonsPanel = new JPanel();
buttonsPanel.setBorder(BorderFactory.createLineBorder(Color.black));
buttonsPanel.setPreferredSize(new Dimension(500, 100));
}
return buttonsPanel;
}
private JButton getClearButton() {
if(clearButton == null){
clearButton = new JButton("Clear");
clearButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
getDrawPanel().clearLines();
}
});
}
return clearButton;
}
private JButton getDcomp() {
if(dcomp == null){
dcomp = new JButton("Complete");
dcomp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
getDrawPanel().createmesh();
getDrawPanel().repaint();
}
});
}
return dcomp;
}
// end begin getters and setters for gui components
//as always program entry-point
public static void main(String[] args) {
MainWindow wnd = new MainWindow();
wnd.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
wnd.setPreferredSize(new Dimension(500, 600));
wnd.setLocationRelativeTo(null);
wnd.pack();
wnd.setVisible(true);
}
}
DrawPanel：
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class DrawPanel extends JPanel implements MouseListener {
private static final long serialVersionUID = -7726303639184194659L;
// begin members
private DrawLines dlines;
private DrawPoints dpoints;
// dont know what these members do
private Point p1 = new Point(100, 100);
public int Xpoint[][] = new int[500][30];
public int Ypoint[][] = new int[500][30];
private double Xmpoint[][] = new double[500][1000]; // [i
// γραμμή][συντεταγμένη
// Χ]
private double Ympoint[][] = new double[500][1000];
private double Vec[][][] = new double[500][2][500]; // [i γραμμή][0,1][0α
// 1β]
private double dist[] = new double[10000];
private boolean drawing;
private int c1;
private int c2;
// end members
public DrawPanel() {
dlines = new DrawLines();
dpoints = new DrawPoints();
addMouseListener(this);
}
// begin class logic
public void clearLines(){
dlines.clearLines();
repaint();
}
// dont know what this does
public void createmesh() {
int mdi = 0;
for (int j = 0; j <= c2; j++) {
for (int i = 0; i < c1 - 1; i++) {
// Υπολογισμός a και b συνιστωσών της εξίσωσης της γραμμής
Vec[i][0][mdi] = (Ypoint[i + 1][j] - Ypoint[i][j])
/ (Xpoint[i + 1][j] - Xpoint[i][j]);
Vec[i][1][mdi] = Ypoint[i][j] - Xpoint[i][j] * Vec[i][1][mdi];
// Υπολογισμός μέτρου διανύσματος
dist[mdi] = Math.sqrt(Math.pow(Xpoint[i][j] - Xpoint[i + 1][j],
2) + Math.pow(Ypoint[i][j] - Ypoint[i + 1][j], 2));
// Υπολογισμός ενδιάμεσον σημείων
int nkom = 3;
double xa = Xpoint[i][j];
double ya = Ypoint[i][j];
for (int ii = 0; ii < nkom; ii++) {
double a = Vec[i][0][mdi];
double b = Vec[i][1][mdi];
Xmpoint[i][ii] = (-((2 * a) * (b - ya) - 2 * xa) + Math
.sqrt(Math.abs(Math.pow(
((2 * a) * (b - ya) - 2 * xa), 2)
- 4
* (1 + a * a)
* (xa * xa + Math.pow((b - ya), 2) - Math
.pow(dist[mdi] / nkom, 2)))))
/ (2 + 2 * a * a);
Ympoint[i][ii] = a * Xmpoint[i][ii] + b;
double xm11 = Xmpoint[i][ii];
double ym11 = Ympoint[i][ii];
int xm1 = (int) xm11;
int ym1 = (int) ym11;
dpoints.addPoint(xm1, ym1);
System.out.println("i:" + ym11 + "...ii:" + ym1);
xa = Xmpoint[i][ii];
ya = Ympoint[i][ii];
}
mdi++;
}
}
}
// end class logic
// begin MouseListener implementation
@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mousePressed(MouseEvent e) {
if (SwingUtilities.isRightMouseButton(e)) {
drawing = false;
c2++;
}
if (SwingUtilities.isLeftMouseButton(e)) {
p1 = e.getPoint();
Xpoint[c1][c2] = p1.x;
Ypoint[c1][c2] = p1.y;
if (c1 > 3) {
for (int j = 0; j < c2 + 1; j++) {
for (int i = 0; i < c1; i++) {
if ((Math.abs(Xpoint[i][j] - Xpoint[c1][c2]) < 10)
&& (Math.abs(Ypoint[i][j] - Ypoint[c1][c2]) < 10)) {
Xpoint[c1][c2] = Xpoint[i][j];
Ypoint[c1][c2] = Ypoint[i][j];
System.out.println(Xpoint[i][j]);
}
}
}
}
if (drawing == true) {
dlines.addLine(Xpoint[c1][c2], Ypoint[c1][c2],
Xpoint[c1 - 1][c2], Ypoint[c1 - 1][c2]);
}
c1++;
drawing = true;
repaint();
}
}
@Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
// end MouseListener implementation
// beging PAINTING
@Override
protected void paintComponent(Graphics g) {
System.out.println("paintComponent");
super.paintComponent(g);
dlines.draw(g);
dpoints.draw(g);
}
// end PAINTING
}
DrawPoints：
import java.awt.Graphics;
import java.util.LinkedList;
public class DrawPoints {
public DrawPoints() {
}
private static class Point {
final int x;
final int y;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
}
private final LinkedList<Point> points = new LinkedList<Point>();
public void addPoint(int x, int y) {
points.add(new Point(x, y));
}
public void draw(Graphics g){
for (Point point : points) {
g.drawOval(point.x, point.y, 5, 5);
}
}
}
DrawLines：
import java.awt.Graphics;
import java.util.LinkedList;
public class DrawLines{
public DrawLines() {
}
private static class Line {
final int x1;
final int y1;
final int x2;
final int y2;
public Line(int x1, int y1, int x2, int y2) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
}
private final LinkedList<Line> lines = new LinkedList<Line>();
public void addLine(int x1, int x2, int x3, int x4) {
lines.add(new Line(x1, x2, x3, x4));
}
public void clearLines() {
lines.clear();
}
public void draw(Graphics g){
for (Line line : lines) {
g.drawLine(line.x1, line.y1, line.x2, line.y2);
}
}
}
我觉得处理这样的事情是一个好主意。你想在Panel上绘制一些东西，然后将它传递给保存数据的对象，让它们绘制到它们的公共 canvas ，就像我在DrawPoints-和DrawLines中使用void draw(Graphics g)方法一样-class。
我希望这会对你有所帮助。 如果有什么不清楚，可以随意询问。