【发布时间】：2014-09-08 08:41:25
【问题描述】：
我是 Java swing 桌面图形应用程序的新手，我遇到了一个问题，请建议我需要选择一些矩形并用我们是否有任何预定义的概念来填充矩形，如果有的话，请建议我开始一个绘图
import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
@SuppressWarnings("serial")
public class Exam extends JPanel implements MouseMotionListener {
private static final int recW = 50;
private static final int MAX = 100;
private Rectangle[] rect = new Rectangle[MAX];
private int numOfRecs = 0;
private int currentSquareIndex = -1;
private Point startPoint = new Point();
private Point currentPoint = new Point();
private int x, y, width, height;
private Stroke dashedStroke = new BasicStroke(0.0f, BasicStroke.CAP_ROUND,
BasicStroke.CAP_SQUARE, 5.0f, new float[] { 5f, 5f, 5f, 5f }, 5.0f);
ArrayList list = new ArrayList();
public Exam() {
addRect(50, 50);
addRect(100, 50);
addRect(150, 50);
addRect(200, 50);
addRect(250, 50);
addRect(300, 50);
addRect(350, 50);
addRect(400, 50);
addRect(450, 50);
addRect(500, 50);
//
addRect(50, 100);
addRect(100, 100);
addRect(150, 100);
addRect(200, 100);
addRect(250, 100);
addRect(300, 100);
addRect(350, 100);
addRect(400, 100);
addRect(450, 100);
addRect(500, 100);
//
addRect(50, 150);
addRect(100, 150);
addRect(150, 150);
addRect(200, 150);
addRect(250, 150);
addRect(300, 150);
addRect(350, 150);
addRect(400, 150);
addRect(450, 150);
addRect(500, 150);
//
addRect(50, 200);
addRect(100, 200);
addRect(150, 200);
addRect(200, 200);
addRect(250, 200);
addRect(300, 200);
addRect(350, 200);
addRect(400, 200);
addRect(450, 200);
addRect(500, 200);
addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent evt) {
startPoint = evt.getPoint();
}
public void mouseReleased(MouseEvent e) {
System.out.println(" mouseReleased is " + e.getX() + " y i s "
+ e.getY());
Graphics g = getGraphics();
Graphics2D g2 = (Graphics2D) g;
g2.setComposite(AlphaComposite.SrcOver.derive(0.8f));
Color myColour = new Color(255, 0, 0);
g.setColor(myColour);
x = Math.min(startPoint.x, currentPoint.x);
y = Math.min(startPoint.y, currentPoint.y);
width = Math.abs(startPoint.x - currentPoint.x);
height = Math.abs(startPoint.y - currentPoint.y);
rect[numOfRecs] = new Rectangle(x, y, width, height);
// System.out.println("list size is:"+list.size());
Rectangle ggg=new Rectangle(x, y, width, height);
for(Rectangle rect3d: rect){
if(ggg.intersects(rect3d)){
g2.fill(rect3d);
}
else
System.out.println("doesn't contains");
}
repaint();
}
});
addMouseMotionListener(this);
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (int i = 0; i < numOfRecs; i++) {
((Graphics2D) g).draw(rect[i]);
list.add(rect[i]);
}
x = Math.min(startPoint.x, currentPoint.x);
y = Math.min(startPoint.y, currentPoint.y);
width = Math.abs(startPoint.x - currentPoint.x);
height = Math.abs(startPoint.y - currentPoint.y);
((Graphics2D) g).setStroke(dashedStroke);
g.setColor(Color.BLACK);
g.drawRect(x, y, width, height);
// Rectangle dashedRec=new Rectangle(x, y, width, height);
}
public void addRect(int x, int y) {
if (numOfRecs < MAX) {
rect[numOfRecs] = new Rectangle(x, y, recW, recW);
currentSquareIndex = numOfRecs;
numOfRecs++;
repaint();
}
}
@Override
public void mouseMoved(MouseEvent event) {
}
@Override
public void mouseDragged(MouseEvent event) {
currentPoint = event.getPoint();
repaint();
}
public static void main(String[] args) {
JFrame jFrame = new JFrame();
jFrame.setTitle("");
jFrame.setSize(600, 300);
Container cPane = jFrame.getContentPane();
cPane.add(new Exam());
jFrame.setVisible(true);
}
}
【问题讨论】：
-
欢迎来到 Stack Overflow。请阅读Stack Overflow: How to ask 和Jon Skeet's Question Checklist，了解如何提出一个好的问题，从而产生好的有用的答案。
-
请向我们展示您的尝试，一些代码，也许还有一个 jsfiddle
-
MouseMotionListener 对 mousePressed/Clicked 没有反应
-
我已经粘贴了一些代码，请检查一次并建议我完成矩形的选择
-
鼠标拖动与鼠标右移监听相关
标签： java swing graphics mouselistener mousemotionlistener