我使用绘画组件和 2D 图形在 JPanel 上绘制线条，但 JPanel 的背景设置为网格，当用户输入某些尺寸时绘制该网格。单击按钮时如何清除 JPanel 上绘制的线条，但使用绘制的网格线再次重新生成新面板？对于清除按钮的操作事件方法，我尝试使用 repaint()、removeAll() 并创建 JPanel 的新实例，但这些似乎都不起作用。
以下是具有主面板和按钮功能的类的代码:
package floorplan;
/**
*
* @author xodkx
*/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.GridLayout;
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;
import javax.swing.JRadioButton;
import javax.swing.SwingUtilities;
public class FloorPlan extends JFrame
{
private JPanel backPanel = new JPanel();
private JPanel toolsPanel = new JPanel();
private JFrame chooseFurniture;
private JFrame chooseFixture;
private JFrame chooseFramework;
private JButton furnitureButton = new JButton();
private JButton fixturesButton = new JButton();
private JButton frameworkButton = new JButton();
private JButton deleteButton = new JButton();
private JButton saveButton = new JButton();
private JButton clearButton = new JButton();
private JButton closeButton = new JButton();
private JRadioButton wall = new JRadioButton("Wall");
private JRadioButton door = new JRadioButton("Door");
private JRadioButton window = new JRadioButton("Window");
Floor floor = new Floor();
public FloorPlan()
{
super("Floor Plan Generator");
createWindow();
buttonFunctions();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setVisible(true);
}
private void createWindow()
{
backPanel.setLayout(new BorderLayout());
backPanel.setBorder(BorderFactory.createEmptyBorder(200, 200, 200, 200));
GridLayout panelLayout = new GridLayout();
frameworkButton.setText("Framework");
fixturesButton.setText("Fixtures");
furnitureButton.setText("Furniture");
deleteButton.setText("Delete");
saveButton.setText("Save");
clearButton.setText("Clear");
add(backPanel, BorderLayout.CENTER);
backPanel.add(toolsPanel, BorderLayout.NORTH);
backPanel.add(floor, BorderLayout.CENTER);
backPanel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
toolsPanel.add(frameworkButton);
toolsPanel.add(fixturesButton);
toolsPanel.add(furnitureButton);
toolsPanel.add(deleteButton);
toolsPanel.add(saveButton);
toolsPanel.add(clearButton);
add(backPanel);
}
private void buttonFunctions()
{
frameworkButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(final ActionEvent e)
{
chooseFramework = new JFrame("Pick A Framework");
chooseFramework.setSize(250,250);
chooseFramework.setLayout(new GridLayout(4,1));
chooseFramework.add(wall);
chooseFramework.add(door);
chooseFramework.add(window);
chooseFramework.add(closeButton);
closeButton.setText("Close");
wall.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
floor.setFramework(Framework.WALL);
}});
door.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
floor.setColor(Color.RED);
floor.setFramework(Framework.DOOR);
}});
window.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
floor.setColor(Color.BLUE);
floor.setFramework(Framework.WALL);
}});
closeButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
chooseFramework.setVisible(false);
}
});
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
chooseFramework.setVisible(true);
}
});
furnitureButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(final ActionEvent e)
{
chooseFurniture = new JFrame("Pick Furniture to add");
chooseFurniture.setSize(250,250);
chooseFurniture.setLayout(new GridLayout(4,1));
chooseFurniture.add(closeButton);
closeButton.setText("Close");
closeButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
chooseFurniture.setVisible(false);
}
});
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
chooseFurniture.setVisible(true);
}
});
fixturesButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(final ActionEvent e)
{
chooseFixture = new JFrame("Pick Furniture to add");
chooseFixture.setSize(250,250);
chooseFixture.setLayout(new GridLayout(4,1));
chooseFixture.add(closeButton);
closeButton.setText("Close");
closeButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
chooseFixture.setVisible(false);
}
});
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
chooseFixture.setVisible(true);
}
});
**clearButton.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(final ActionEvent e)
{
**//THIS IS WHERE I WANT TO CLEAR THE JPANEL WHEN THIS BUTTON IS CLICKED**
}
});**
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
FloorPlan floorPlan = new FloorPlan();
}
});
}
}
这是执行所有图形操作并绘制到 JPanel 上的类
package floorplan;
/**
*
* @author xodkx
*/
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.awt.event.MouseListener;
public class Floor extends JPanel implements MouseListener, MouseMotionListener
{
private static final int WIDTH = Integer.parseInt(JOptionPane.showInputDialog("Please
enter the width of your room"));
private static final int LENGTH = Integer.parseInt(JOptionPane.showInputDialog("Please
enter the width of your room"));
private static final Color BACKGROUND = Color.WHITE;
private static final Color INITIAL_COLOUR = Color.BLACK;
private static final Framework INITIAL_FRAMEWORK = Framework.WALL;
private MouseState state = MouseState.IDLE;
private Framework frameworkType = INITIAL_FRAMEWORK;
private Color colour = INITIAL_COLOUR;
private Point start = null;
private Point end = null;
private Point startpt = null;
private Point endpt = null;
private BufferedImage bufImage = null;
public Floor()
{
setPreferredSize(new Dimension(LENGTH,WIDTH));
setBackground(Color.white);
setBorder(BorderFactory.createLineBorder (Color.black, 5));
this.addMouseListener(this);
this.addMouseMotionListener(this);
}
public void setColor(Color color)
{
colour = color;
}
public void setFramework(Framework framework)
{
frameworkType = framework;
}
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
if(bufImage == null)
{
int h = this.getHeight();
int w = this.getWidth();
bufImage = (BufferedImage)this.createImage(h,w);
Graphics2D gc = bufImage.createGraphics();
gc.setColor(BACKGROUND);
gc.fillRect(0, 0, w, h);
}
g2.drawImage(bufImage,null,0,0);
drawGrid(g2);
if(state == MouseState.DRAGGING)
{
createComponent(g2);
}
}
public void drawGrid(Graphics g2)
{
int gridDivisions = 20;
int divisionSize = WIDTH/gridDivisions;
int grid = WIDTH*LENGTH;
g2.setColor(Color.lightGray);
for(int i=1; i<grid; i++)
{
int x = i * divisionSize;
g2.drawLine(x,0,x,getSize().height);
}
for(int i=1; i<grid; i++)
{
int y = i*divisionSize;
g2.drawLine(0,y,getSize().width,y);
}
}
public void createComponent(Graphics2D g2)
{
g2.setColor(colour);
switch (frameworkType)
{
case WALL:
g2.setStroke(new BasicStroke(5));
g2.drawLine(start.x, start.y, end.x,end.y);
break;
case DOOR:
g2.setStroke(new BasicStroke(5));
g2.drawLine(start.x, start.y, end.x,end.y);
break;
case WINDOW:
g2.setStroke(new BasicStroke(5));
g2.drawLine(start.x, start.y, end.x,end.y);
break;
default:
g2.drawString("test", 10, 20);
break;
}
}
@Override
public void mousePressed(MouseEvent e)
{
state = MouseState.DRAGGING;
start = e.getPoint();
end = start;
}
@Override
public void mouseDragged(MouseEvent e)
{
state = MouseState.DRAGGING;
end = e.getPoint();
this.repaint();
}
@Override
public void mouseReleased(MouseEvent e)
{
end = e.getPoint();
if(state == MouseState.DRAGGING)
{
state = MouseState.IDLE;
createComponent(bufImage.createGraphics());
this.repaint();
}
}
@Override
public void mouseClicked(MouseEvent e)
{
}
@Override
public void mouseEntered(MouseEvent e)
{
}
@Override
public void mouseExited(MouseEvent e)
{
}
@Override
public void mouseMoved(MouseEvent e)
{
}
}
最佳答案
目前尚不清楚您想要如何合并显示网格的逻辑。这是一个如何切换它的示例，仅供您引用。在Floor类中添加boolean标志来控制是否显示网格。然后在Floor.paintComponent()中根据该boolean标志的值绘制网格。更改标志的值应该会触发重新绘制。然后，更改 FloorPlan 类中此标志的值，以响应操作或某些其他程序逻辑。这是一个简单的实现，当单击 clear 按钮时切换网格:
楼层等级:
private boolean displayGrid = true;
public boolean isDisplayGrid() {
return displayGrid;
}
public void setDisplayGrid(boolean displayGrid) {
this.displayGrid = displayGrid;
repaint();
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
...
if (displayGrid)
drawGrid(g2);
}
平面图类:
clearButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(final ActionEvent e) {
floor.setDisplayGrid(!floor.isDisplayGrid());
}
});
编辑:
看来我完全误解了你的问题。如果我理解正确的话，您想在单击按钮时清除绘图。看起来所有的绘图都是在 Floor 类中的 bufImage 上完成的。只需重置此图像即可，即:
楼层等级:
public void clear() {
bufImage.flush();
bufImage = null;
repaint();
}
平面图类:
clearButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(final ActionEvent e) {
floor.clear();
}
});
关于java - 如何清除 Jpanel 但保留网格线？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14691733/