仿淘宝图片放大（java GUI实现）

全图为原图的缩小

图片并非真的放大（图片真正意义上的放大会失真），而是截取原图的一部分显示

放大后的图片可拖动

 

package come.wang.picture1;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import javax.swing.JFrame;

public class MagnifyPicture {

 /**

  * 方法的用途:仿淘宝图片放大

  *

  * @param args

  */

 private JFrame frame;

 private TuPian panel1;

 

 private TuPian2 panel2;

 private String imageAddrs = "images\\1.jpg";

 public MagnifyPicture() {

  super();

  frame = new JFrame("图片放大");

  frame.setBounds(300, 200, 900, 600);

  frame.setVisible(true);

  int panel1Width = 300;

  // imageAddrs 图片路径、600，宽、400，高、panel1Width小图宽，小图高是根据原图计算出来的。

  panel2 = new TuPian2(400, 300);

  panel1 = new TuPian(imageAddrs, panel1Width, panel2);

  panel1.setLocation(20, 20);

  panel2.setLocation(320, 20);

  frame.setLayout(null);

  frame.add(panel1);

  frame.add(panel2);

  frame.validate();

  frame.repaint();

  frame.addWindowListener(new WindowAdapter() {

   public void windowClosing(WindowEvent arg0) {

    System.exit(0);

   }

  });

 }

 public static void main(String[] args) {

  new MagnifyPicture();

 }

}

 

package come.wang.picture1;

import java.awt.Cursor;

import java.awt.Graphics;

import java.awt.Image;

import java.awt.Point;

import java.awt.Toolkit;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseMotionListener;

import javax.swing.BorderFactory;

import javax.swing.ImageIcon;

import javax.swing.JPanel;

public class TuPian extends JPanel implements MouseMotionListener {

 private static final long serialVersionUID = 1L;

 protected ImageIcon icon;

 private int size1 = 300;

 private TuPian2 panel2 ;

 private JPanel filedPanel ;

 private Image image ;

 //构造函数的参数：str 图片的路径，size1 面板的宽，高根据图片比例计算得来

 // panel2 显示放大图片面板

 public TuPian(final String str,final int size1,final TuPian2 panel2) {

  super();

  icon = new ImageIcon(str);

  image = icon.getImage();

  panel2.createImage(str);

  panel2.setSourceSize(size1);

  

  this.size1 = size1;

  this.setSize(size1, size1 * image.getHeight(null) / image.getWidth(null));

  

  this.panel2 = panel2;

  filedPanel = new JPanel();

  int fpw = this.getWidth()*panel2.getWidth()/image.getWidth(null);

  int fph = this.getHeight()*panel2.getHeight()/image.getHeight(null);

  filedPanel.setSize(fpw,fph);

  filedPanel.setOpaque(false);

  filedPanel.setBorder(BorderFactory.createEtchedBorder());

  filedPanel.setVisible(false);

  this.setLayout(null);

  this.add(filedPanel);

  //自定义鼠标样式

  Toolkit kit = Toolkit.getDefaultToolkit();   

  Image img = kit.getImage("images\\1.png");

  Cursor dynamiteCuror = kit.createCustomCursor(img, new Point(10,10),"dynamite stick") ;     

  setCursor(dynamiteCuror);

  //自定义鼠标样式

  

  this.addMouseMotionListener(this);

  this.addMouseListener(new MouseAdapter(){

   public void mouseEntered(MouseEvent e) {

    panel2.setVisible(true);

    panel2.createImage(str);

    panel2.setSourceSize(size1);

    

   }

   public void mouseExited(MouseEvent e) {

    filedPanel.setVisible(false);

   

   }

  });

  setOpaque(false);//设置panel为透明的。显示图片是不闪动

 }

 

 protected void paintComponent(Graphics g) {

  super.paintComponent(g);

  // 图片缩放到panel大小

  g.drawImage(image, 0, 0, size1, size1* image.getHeight(null)

    / image.getWidth(null), null);

  this.repaint();

 }

 public void mouseDragged(MouseEvent e) {

 }

 public void mouseMoved(MouseEvent e) {

  Point point = this.getMousePosition();

 // System.out.println("X:"+point.getX()+"Y:"+point.getY());

  int xx = (int)point.getX();

  int yy = (int)point.getY();

  int xxx = xx-filedPanel.getWidth()/2;

  int yyy = yy-filedPanel.getHeight()/2;

  //处理边界

  xxx = xxx<=0?0:xxx;

  yyy = yyy<=0?0:yyy;

  xxx = xxx>=this.getWidth()-filedPanel.getWidth()?this.getWidth()-filedPanel.getWidth():xxx;

  yyy = yyy>=this.getHeight()-filedPanel.getHeight()?this.getHeight()-filedPanel.getHeight():yyy;

  filedPanel.setVisible(true);

  filedPanel.setLocation(xxx,yyy );

  

  panel2.changeImage(xx,yy);

 }

 

 

}

 

package come.wang.picture1;

import java.awt.Graphics;

import java.awt.Image;

import java.awt.Point;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseMotionAdapter;

import javax.swing.ImageIcon;

import javax.swing.JPanel;

public class TuPian2 extends JPanel {

 private static final long serialVersionUID = 1L;

 protected ImageIcon icon;

 private int w = 200;// 放大面板的宽

 private int h = 200;// 放大面板的高

 private int sourceSize = 300;// 小图面板的宽

 private int XX;// 截图起始点x

 private int YY;// 截图起始点y

 private Image image;

 private int[] begin;//拖动图片起始点

 private int[] end;//拖动图片终点

 public void createImage(String str) {

  icon = new ImageIcon(str);

  image = icon.getImage();

 }

 public void setSourceSize(int sourceSize) {

  this.sourceSize = sourceSize;

 }

 public TuPian2(int w, int h) {// 初始化时候后需要两个参数：宽和高

  super();

  this.w = w;

  this.h = h;

  begin = new int[2];

  end = new int[2];

  // 根据图片的比例设置面板大小

  // h = (w* image.getHeight(null))/ image.getWidth(null);

  this.setSize(w, h);

  setOpaque(false);//设置panel透明

  setVisible(false);

  addMouseMotionListener(new MouseMotionAdapter() {

   public void mouseDragged(MouseEvent arg0) {

    Point  movePoint = getMousePosition();

    if(movePoint!=null){

     end[0] = (int) movePoint.getX();

     end[1] = (int) movePoint.getY();

     int changeX = end[0] - begin[0];

     int changeY = end[1] - begin[1];

     //此函数每调用一次，此次鼠标的结束位置，作为下一次鼠标的开始位置

     begin[0]=end[0];

     begin[1]=end[1];

     

     // 计算移动方向

     XX = changeX < 0 ? XX - changeX : changeX > 0 ? XX = XX

       - changeX : XX;

     YY = changeY < 0 ? YY - changeY : changeY > 0 ? YY = YY

       - changeY : YY;

     drawImage();

    }

   }

  });

  addMouseListener(new MouseAdapter() {

   public void mousePressed(MouseEvent arg0) {

    Point point = getMousePosition();

    begin[0] = (int) point.getX();

    begin[1] = (int) point.getY();

   }

   

  });

 }

 protected void paintComponent(Graphics g) {

  super.paintComponent(g);

  g.drawImage(image, 0, 0, w, h, this.XX, this.YY, this.XX + w, this.YY

    + h, null);

 }

 public void changeImage(int XX, int YY) {

  // 按比例计算出鼠标“在”实际图像上的位置

  int xx2 = (XX * image.getWidth(null)) / sourceSize;

  int yy2 = (YY * image.getWidth(null)) / sourceSize;

  // 计算截图起始角，使得放大的图片以鼠标为中心

  this.XX = xx2 - w / 2;

  this.YY = yy2 - h / 2;

  drawImage();

 }

 public void drawImage() {

  // 处理边界

  this.YY = this.YY < 0 ? 0 : this.YY;

  this.XX = this.XX < 0 ? 0 : this.XX;

  this.XX = this.XX > image.getWidth(null) - w ? image.getWidth(null) - w

    : this.XX;

  this.YY = this.YY > image.getHeight(null) - h ? image.getHeight(null)

    - h : this.YY;

  // 根据计算参数，绘制放大后的图片（实际是取得图片的部分显示，不是真的放大，小面板上的图片是原图片的缩小）

  this.paintComponent(super.getGraphics());

 }

}

运行效果：