我正在创建一个 map 程序，它应该能够添加地铁、学校等地点。
我可以打开一张 map 图片，并且我的窗口应该调整大小以适合该图像。现在我不希望能够向 map (我的三角形)添加类似的图钉。问题是我无法让它工作。我有一个 MouseAdapter，它应该收集我的 X 和 Y 并将我的三角形放在 map 上。它不起作用，我不明白为什么..当我创建MapPanel时，我什至硬编码了一个三角形，该三角形显示出来，但它总是最终出现在 map 的顶部中心..即使当我创建时更改 x 和 y 的值..
这是我的主程序
package inlupp2_prog2;
import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import java.awt.*;
import java.awt.event.*;
import java.io.File;
import java.util.*;
public class MapProgram extends JFrame {
JComboBox place;
MapPanel mp = null;
JTextField searchField;
JButton searchButton, hideButton, deletePlaceButton, whatIsHere, hideCat, newCat, delCat;
JFileChooser jfc = new JFileChooser(".");
boolean changed = false;
MapProgram(){
super("inlupp2 av Filip Blom (fibl7163)");
//FILEMENU TOPP
JMenuBar fileBar = new JMenuBar();
setJMenuBar(fileBar);
JMenu archive = new JMenu("File");
fileBar.add(archive);
JMenuItem open = new JMenuItem("Open");
archive.add(open);
open.addActionListener(new OpenLis());
JMenuItem save = new JMenuItem("Save");
archive.add(save);
//ACTIONLISTENER
JMenuItem close = new JMenuItem("Close");
archive.add(close);
close.addActionListener(new CloseLis());
//valmeny TOPP
JPanel north = new JPanel();
add(north, BorderLayout.NORTH);
north.add(new JLabel("New"));
String[] places = { "NamedPlace", "DescribedPlace" };
place = new JComboBox(places);
north.add(place);
//ACTIONLISTENER
searchField = new JTextField("search", 10);
north.add(searchField);
//ACTIONLISTERNER
searchButton = new JButton("Search");
north.add(searchButton);
//ACTIONLISTENER
hideButton = new JButton("Hide places");
north.add(hideButton);
//ACTIONLISTER
deletePlaceButton = new JButton("Delete places");
north.add(deletePlaceButton);
//ACTIONLISTERN
whatIsHere = new JButton("What is here?");
north.add(whatIsHere);
//ACTIONLISTER
//kategorier ÖST
JPanel east = new JPanel();
add(east, BorderLayout.EAST);
east.add(new JLabel("Categories"));
//SCROLLPANE
hideCat = new JButton("Hide category");
east.add(hideCat);
//ACTIONLISTER
newCat = new JButton("New category");
east.add(newCat);
//ACTIONLISTERN
delCat = new JButton("Delete category");
east.add(delCat);
//ACTIONLISTER
BoxLayout eastLayout = new BoxLayout(east, BoxLayout.Y_AXIS);
east.setLayout(eastLayout);
addWindowListener(new CloseLis());
setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
setSize(800,300);
setVisible(true);
setLocationRelativeTo(null);
setResizable(false);
}
class MouseLis extends MouseAdapter{
public void MouseClicked(MouseEvent mev){
int x = mev.getX();
int y = mev.getY();
Place p = new Place(x,y);
mp.add(p);
mp.repaint();
mp.validate();
}
}
class OpenLis implements ActionListener{
public void actionPerformed(ActionEvent ave){
int answer = jfc.showOpenDialog(MapProgram.this);
if(answer != JFileChooser.APPROVE_OPTION){
return;
}
File file = jfc.getSelectedFile();
String filename = file.getAbsolutePath();
if(mp != null){
remove(mp);
}
mp = new MapPanel(filename);
add(mp, BorderLayout.CENTER);
// mp.add(new Place(500,500));
pack();
validate();
repaint();
mp.addMouseListener(new MouseLis());
}
}
class CloseLis extends WindowAdapter implements ActionListener{
public void closeSave(){
if(changed){
int answer = JOptionPane.showConfirmDialog(null,"You have unsaved changes...\nYou Still want to close this program?", "WARNING", JOptionPane.YES_NO_OPTION);
// int answer = JOptionPane.showConfirmDialog(MapProgram.this, "You have unsaved changes...\nYou Still want to close this program?");
if(answer==0){
System.exit(0);
}
}
System.exit(0);
}
public void windowClosing(WindowEvent wev){
closeSave();
}
public void actionPerformed(ActionEvent ave){
closeSave();
}
}
public static void main(String[] args){
new MapProgram();
}
}
这是我创建三角形的类
package inlupp2_prog2;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class Place extends JComponent {
public Place(int x, int y){
setBounds(x,y,50,50);
Dimension d = new Dimension(50, 50);
setPreferredSize(d);
setMaximumSize(d);
setMinimumSize(d);
}
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLACK);
int[] xes = {0,25,50};
int[] yes = {0,50,0};
g.fillPolygon(xes, yes, 3);
}
}
这是我的 map 面板
package inlupp2_prog2;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
public class MapPanel extends JPanel{
private ImageIcon map;
public MapPanel(String filename){
map = new ImageIcon(filename);
int w = map.getIconWidth();
int h = map.getIconHeight();
Dimension d = new Dimension(w,h);
setPreferredSize(d);
setMaximumSize(d);
setMinimumSize(d);
}
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(map.getImage(), 0, 0, getWidth(), getHeight(), this);
}
}
最佳答案
class MouseLis extends MouseAdapter{
public void MouseClicked(MouseEvent mev){
int x = mev.getX();
int y = mev.getY();
Place p = new Place(x,y);
mp.add(p);
mp.repaint();
mp.validate();
}
}
请注意mouseClicked != MouseClicked。经验教训:始终在重写方法时使用@Override，因为这会显示错误:
class MouseLis extends MouseAdapter{
@Override
public void MouseClicked(MouseEvent mev){
int x = mev.getX();
int y = mev.getY();
Place p = new Place(x,y);
mp.add(p);
mp.repaint();
mp.validate();
}
}
注意:我是如何发现你的错误的？通过使用您的代码并在其中添加 println ，包括:
public void MouseClicked(MouseEvent mev) {
System.out.println("" + mev.getPoint());
int x = mev.getX();
int y = mev.getY();
Place p = new Place(x, y); //!!
p.setBorder(BorderFactory.createLineBorder(Color.red)); //!!
mp.add(p);
mp.repaint();
mp.validate();
}
这个家伙从来没有打印出来，所以它让我开始寻找它不起作用的原因。另外，将来请考虑创建并发布 Minimal, Complete, and Verifiable Example Program 。我们不想看到您的整个程序，而是您应该将代码压缩为仍然可以编译的最小代码，没有与您的问题无关的额外代码，但仍然演示您的问题。您很可能通过简单地尝试隔离和暴露错误来自行解决问题。
关于java - 无法在我的图片上画出三角形，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/29827261/