Java 如何拖动对象
我想拖动一个框,我想我的鼠标光标是我在拖动矩形时在矩形中单击的位置。我尝试了这段代码,当我尝试拖动时,我得到了一堆错误Java 如何拖动对象,java,applet,cursor,drag,Java,Applet,Cursor,Drag,我想拖动一个框,我想我的鼠标光标是我在拖动矩形时在矩形中单击的位置。我尝试了这段代码,当我尝试拖动时,我得到了一堆错误 import objectdraw.*; import java.awt.*; public class TouchWindow extends WindowController { private FilledRect a; private boolean b; private Location c; private int x;
import objectdraw.*;
import java.awt.*;
public class TouchWindow extends WindowController
{
private FilledRect a;
private boolean b;
private Location c;
private int x;
private int y;
public void begin()
{
b=false;
a=new FilledRect(0,0,50,50,canvas);
}
public void onMouseClick(Location pt)
{
if(a.contains(pt))
{
b=true;
pt=c;
}
}
public void onMouseDrag(Location pt2)
{
if(b==true)
{
x=(int)c.getX()-(int)pt2.getX();
y=(int)c.getY()-(int)pt2.getY();
a.move(x,y);
}
}
}
嗯,这里有一个例子,虽然不是小程序,但它可以非常简单地移植
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ShapeMover {
public ShapeMover() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Shape Mover");
initComponents(frame);
frame.pack();
frame.setVisible(true);
}
public static void main(String s[]) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new ShapeMover();
}
});
}
private void initComponents(JFrame frame) {
frame.getContentPane().add(new DragPanel());
}
}
class DragPanel extends JPanel {
Rectangle rect = new Rectangle(0, 0, 100, 50);
int preX, preY;
boolean isFirstTime = true;
Rectangle area;
boolean pressOut = false;
private Dimension dim = new Dimension(400, 300);
public DragPanel() {
setBackground(Color.white);
addMouseMotionListener(new MyMouseAdapter());
addMouseListener(new MyMouseAdapter());
}
@Override
public Dimension getPreferredSize() {
return dim;
}
@Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
if (isFirstTime) {
area = new Rectangle(dim);
rect.setLocation(50, 50);
isFirstTime = false;
}
g2d.setColor(Color.black);
g2d.fill(rect);
}
boolean checkRect() {
if (area == null) {
return false;
}
if (area.contains(rect.x, rect.y, rect.getWidth(), rect.getHeight())) {
return true;
}
int new_x = rect.x;
int new_y = rect.y;
if ((rect.x + rect.getWidth()) > area.getWidth()) {
new_x = (int) area.getWidth() - (int) (rect.getWidth() - 1);
}
if (rect.x < 0) {
new_x = -1;
}
if ((rect.y + rect.getHeight()) > area.getHeight()) {
new_y = (int) area.getHeight() - (int) (rect.getHeight() - 1);
}
if (rect.y < 0) {
new_y = -1;
}
rect.setLocation(new_x, new_y);
return false;
}
private class MyMouseAdapter extends MouseAdapter {
@Override
public void mousePressed(MouseEvent e) {
preX = rect.x - e.getX();
preY = rect.y - e.getY();
if (rect.contains(e.getX(), e.getY())) {
updateLocation(e);
} else {
pressOut = true;
}
}
@Override
public void mouseDragged(MouseEvent e) {
if (!pressOut) {
updateLocation(e);
} else {
}
}
@Override
public void mouseReleased(MouseEvent e) {
if (rect.contains(e.getX(), e.getY())) {
updateLocation(e);
} else {
pressOut = false;
}
}
public void updateLocation(MouseEvent e) {
rect.setLocation(preX + e.getX(), preY + e.getY());
checkRect();
repaint();
}
}
}
导入java.awt.Color;
导入java.awt.Dimension;
导入java.awt.Graphics;
导入java.awt.Graphics2D;
导入java.awt.Rectangle;
导入java.awt.event.MouseAdapter;
导入java.awt.event.MouseEvent;
导入javax.swing.JFrame;
导入javax.swing.JPanel;
导入javax.swing.SwingUtilities;
公共类ShapeMover{
公共ShapeMover(){
JFrame=新JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle(“形状移动器”);
初始组件(框架);
frame.pack();
frame.setVisible(true);
}
公共静态void main(字符串s[]{
SwingUtilities.invokeLater(新的Runnable(){
@凌驾
公开募捐{
新的ShapeMover();
}
});
}
私有组件(JFrame){
frame.getContentPane().add(新的DragPanel());
}
}
类DragPanel扩展了JPanel{
矩形rect=新矩形(0,0,100,50);
intprex,猎物;
布尔值isFirstTime=true;
矩形区域;
布尔值pressOut=false;
私有维度dim=新维度(400300);
公共绘图板(){
挫折地面(颜色:白色);
addMouseMotionListener(新的MyMouseAdapter());
addMouseListener(新的MyMouseAdapter());
}
@凌驾
公共维度getPreferredSize(){
返回暗淡;
}
@凌驾
公共组件(图形g){
超级组件(g);
Graphics2D g2d=(Graphics2D)g;
如果(是第一次){
面积=新矩形(尺寸);
直肠定位(50,50);
isFirstTime=false;
}
g2d.setColor(Color.black);
g2d.填充(矩形);
}
布尔checkRect(){
如果(面积==null){
返回false;
}
if(area.contains(rect.x,rect.y,rect.getWidth(),rect.getHeight())){
返回true;
}
int new_x=rect.x;
int new_y=rect.y;
如果((rect.x+rect.getWidth())>area.getWidth()){
new_x=(int)area.getWidth()-(int)(rect.getWidth()-1);
}
if(矩形x<0){
新的_x=-1;
}
如果((rect.y+rect.getHeight())>area.getHeight()){
new_y=(int)area.getHeight()-(int)(rect.getHeight()-1);
}
if(矩形y<0){
新的y=-1;
}
矩形设置位置(新x,新y);
返回false;
}
私有类MyMouseAdapter扩展了MouseAdapter{
@凌驾
公共无效鼠标按下(MouseEvent e){
preX=rect.x-e.getX();
preY=rect.y-e.getY();
if(rect.contains(e.getX(),e.getY()){
更新位置(e);
}否则{
pressOut=true;
}
}
@凌驾
公共无效鼠标标记(鼠标事件e){
如果(!按出){
更新位置(e);
}否则{
}
}
@凌驾
公共无效MouseEvent(MouseEvent e){
if(rect.contains(e.getX(),e.getY()){
更新位置(e);
}否则{
按出=假;
}
}
public void updateLocation(MouseEvent e){
直肠定位(preX+e.getX(),preY+e.getY());
checkRect();
重新油漆();
}
}
}
+1用于边界检查;也可以看到这个相关的+1,谢谢你,但这并不是很好,边界检查是硬编码的,只看到现在它改变了:P。。。你也有一个很好的例子。