Java 我想一次拖动一个对象,但这段代码一次拖动两个对象
我想一次拖动一个对象,但这段代码一次拖动两个对象Java 我想一次拖动一个对象,但这段代码一次拖动两个对象,java,drag-and-drop,applet,awt,mouse,Java,Drag And Drop,Applet,Awt,Mouse,我想一次拖动一个对象,但这段代码一次拖动两个对象 package javaPgm; import java.applet.*; import java.awt.*; import java.awt.event.*; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import javax.swing.*; import javax.swing.ImageIcon; import java.awt.Colo
package javaPgm;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.*;
import javax.swing.ImageIcon;
import java.awt.Color;
import java.awt.Graphics.*;
public class Drag extends Applet
implements MouseListener, MouseMotionListener {
int width, height;
int x, y; // coordinates of upper left corner of the box
int mx, my; // the most recently recorded mouse coordinates
boolean isMouseDraggingBox = false;
public void init() {
width = getSize().width;
height = getSize().height;
x = width/2 - 20;
y = height/2 - 20;
addMouseListener( this );
addMouseMotionListener( this );
}
public void mouseEntered( MouseEvent e ) { }
public void mouseExited( MouseEvent e ) { }
public void mouseClicked( MouseEvent e ) { }
public void mousePressed( MouseEvent e ) {
mx = e.getX();
my = e.getY();
if ( x < mx && mx < x+40 && y < my && my < y+40 ) {
isMouseDraggingBox = true;
}
e.consume();// consumes the current event
}
public void mouseReleased( MouseEvent e ) {
isMouseDraggingBox = false;
e.consume();
}
public void mouseMoved( MouseEvent e ) { }
public void mouseDragged( MouseEvent e ) {
if ( isMouseDraggingBox ) {
int new_mx = e.getX();
int new_my = e.getY();
x += new_mx - mx;
y += new_my - my;
mx = new_mx;
my = new_my;
repaint();
e.consume();
}
}
public void paint( Graphics g ) {
g.drawRect( 20, 40, 50, 85 );
g.drawString("circle",20 , 38);
Font f = new Font("TimesRoman", Font.PLAIN, 20);// to set font style and size
g.setFont(f);
g.drawString("RED=Positive charge", 175, 188);// to write a text
g.drawString("BLUE=negative charge", 199, 210);
g.drawRect(100,140,60,85);
g.setColor(Color.red);
g.fillOval(x,y,15,15);
g.setColor(Color.blue);
g.fillOval(x-110,y-135,15,15);
setBackground(Color.yellow);
for(int i=0;i<=950;i+=30){// to draw horizontal and vertical lines
g.setColor(Color.orange);
g.drawLine(i,0,i,950);
}
for(int j=0;j<=950;j+=30){
g.drawLine(0, j, 950, j);
}
}
}
packagejavapgm;
导入java.applet.*;
导入java.awt.*;
导入java.awt.event.*;
导入java.awt.event.ItemEvent;
导入java.awt.event.ItemListener;
导入javax.swing.*;
导入javax.swing.ImageIcon;
导入java.awt.Color;
导入java.awt.Graphics.*;
公共类拖动扩展小程序
实现MouseListener、MouseMotionListener{
int宽度、高度;
int x,y;//框左上角的坐标
int mx,my;//最近记录的鼠标坐标
布尔值isMouseDraggingBox=false;
公共void init(){
宽度=getSize().width;
高度=getSize()。高度;
x=宽度/2-20;
y=高度/2-20;
addMouseListener(这个);
addMouseMotionListener(此);
}
公共无效mouseenterned(MouseEvent e){}
公共无效mouseExited(MouseEvent e){}
公共无效mouseClicked(MouseEvent e){}
公共无效鼠标按下(MouseEvent e){
mx=e.getX();
my=e.getY();
如果(x 对于(inti=0;i来说,您需要做的第一件事是找出“对象”之间的区别
接下来你需要的是用一种方便的方法来引用这个对象。你可以使用数组,但我很懒,更喜欢使用列表
一旦你有了这两样东西,绘制框就只需要在列表中循环,然后确定单击了哪个对象就基本上变成了相同的过程
为此,我将一个java.awt.Rectangle
包装在一个自定义的Box
类周围,该类还维护颜色信息,这使得管理变得更加容易,因为Rectangle
有一些非常有用的方法,并且可以很容易地绘制
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JApplet;
import javax.swing.JPanel;
public class WhatADag extends JApplet {
@Override
public void init() {
add(new DragPane());
}
public class DragPane extends JPanel {
private List<Box> boxes;
public DragPane() {
boxes = new ArrayList<>(25);
boxes.add(new Box(0, 0, 50, 50, Color.RED));
boxes.add(new Box(150, 150, 50, 50, Color.BLUE));
MouseAdapter handler = new MouseAdapter() {
private Box hitBox;
private Point offset;
@Override
public void mousePressed(MouseEvent e) {
Point mp = e.getPoint();
for (Box box : boxes) {
if (box.getBounds().contains(mp)) {
hitBox = box;
offset = new Point();
offset.x = mp.x - box.getBounds().x;
offset.y = mp.y - box.getBounds().y;
}
}
}
@Override
public void mouseReleased(MouseEvent e) {
hitBox = null;
}
@Override
public void mouseDragged(MouseEvent e) {
if (hitBox != null) {
Point mp = e.getPoint();
Rectangle bounds = hitBox.getBounds();
bounds.x = mp.x - offset.x;
bounds.y = mp.y - offset.y;
repaint();
}
}
};
addMouseListener(handler);
addMouseMotionListener(handler);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
for (Box rect : boxes) {
g2d.setColor(rect.getColor());
g2d.fill(rect.getBounds());
}
g2d.dispose();
}
}
public class Box {
private Color color;
private Rectangle rectangle;
public Box(int x, int y, int width, int height, Color color) {
rectangle = new Rectangle(x, y, width, height);
setColor(color);
}
public void setColor(Color color) {
this.color = color;
}
public Color getColor() {
return color;
}
public Rectangle getBounds() {
return rectangle;
}
}
}
导入java.awt.Color;
导入java.awt.Dimension;
导入java.awt.Graphics;
导入java.awt.Graphics2D;
导入java.awt.Point;
导入java.awt.Rectangle;
导入java.awt.event.MouseAdapter;
导入java.awt.event.MouseEvent;
导入java.util.ArrayList;
导入java.util.List;
导入javax.swing.JApplet;
导入javax.swing.JPanel;
公共类WhatADag扩展JApplet{
@凌驾
公共void init(){
添加(新的DragPane());
}
公共类DragPane扩展了JPanel{
专用列表框;
公共拖缆机(){
框=新阵列列表(25);
添加(新框(0,0,50,50,颜色.红色));
框。添加(新框(150、150、50、50,颜色。蓝色));
MouseAdapter handler=新的MouseAdapter(){
私人信箱;
专用点偏移;
@凌驾
公共无效鼠标按下(MouseEvent e){
点mp=e.getPoint();
用于(盒子:盒子){
if(box.getBounds()包含(mp)){
hitBox=box;
偏移=新点();
offset.x=mp.x-box.getBounds().x;
offset.y=mp.y-box.getBounds().y;
}
}
}
@凌驾
公共无效MouseEvent(MouseEvent e){
hitBox=null;
}
@凌驾
公共无效鼠标标记(鼠标事件e){
if(hitBox!=null){
点mp=e.getPoint();
矩形边界=hitBox.getBounds();
bounds.x=mp.x-offset.x;
bounds.y=mp.y-offset.y;
重新油漆();
}
}
};
addMouseListener(handler);
addMouseMotionListener(处理程序);
}
@凌驾
公共维度getPreferredSize(){
返回新维度(200200);
}
@凌驾
受保护组件(图形g){
超级组件(g);
Graphics2D g2d=(Graphics2D)g.create();
用于(长方体矩形:长方体){
g2d.setColor(rect.getColor());
填充(rect.getBounds());
}
g2d.dispose();
}
}
公共类箱{
私人色彩;
私有矩形;
公共框(整数x、整数y、整数宽度、整数高度、颜色){
矩形=新矩形(x、y、宽度、高度);
设置颜色(颜色);
}
公共空间设置颜色(颜色){
这个颜色=颜色;
}
公共颜色getColor(){
返回颜色;
}
公共矩形getBounds(){
返回直肠