import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.CropImageFilter;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.ImageProducer;
import java.io.File;
import javax.swing.*;
public class vicePic implements ActionListener {
    JLabel imgLable;
    JFrame mainJframe;
    Container con;
    JTextField fileFiled;
    JButton openBtn,cutBtn;
    JPanel pane;
    JScrollPane spanel;
    ImageIcon img;
    public vicePic(){
        mainJframe=new JFrame("图形显示比例");
        con=mainJframe.getContentPane();
        pane=new JPanel();
        pane.setLayout(new FlowLayout());
        openBtn=new JButton("打开文件");
        openBtn.addActionListener(this);
        cutBtn=new JButton("剪切图片");
        cutBtn.addActionListener(this);
        fileFiled=new JTextField();
        fileFiled.setColumns(20);
        pane.add(fileFiled);
        pane.add(openBtn);
        pane.add(cutBtn);
        imgLable =new JLabel();
        spanel=new JScrollPane(imgLable);
        con.add(pane,BorderLayout.NORTH);
        con.add(spanel,BorderLayout.CENTER);
        mainJframe.setSize(800, 800);
        mainJframe.setVisible(true);
        mainJframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        }
    @Override
    public void actionPerformed(ActionEvent e) {
        String cmd=e.getActionCommand();
        ImageFilter cropFilter;
        Image croppedImage;
        ImageProducer produer;
        if(cmd.equals("打开文件")){
        try{
            JFileChooser chooser=new JFileChooser();
            if(chooser.showOpenDialog(mainJframe)==JFileChooser.APPROVE_OPTION){
                File tempfile=chooser.getSelectedFile();
                fileFiled.setText(tempfile.toString());
                img=new ImageIcon(fileFiled.getText());
                imgLable.setIcon(img);      
                }http://www.huiyi8.com/jiaoben/
        }catch(Exception el){
            JOptionPane.showMessageDialog(mainJframe, "图品无法显示");

        }
        }
        if(cmd.equals("剪切图片")){
            cropFilter=new CropImageFilter(100, 100, 200, 200);
            produer=new FilteredImageSource(img.getImage().getSource(), cropFilter);
            croppedImage=Toolkit.getDefaultToolkit().createImage(produer);
            imgLable.setIcon(new ImageIcon(croppedImage));
            }
    }
    public static void main(String[] args){
        new vicePic();
    }

}