我的摇摆应用程序中的边框布局出了什么问题?

时间:2011-09-22 17:57:55

标签: java swing layout

我有一个简单的应用程序,我想在可滚动面板中显示一个大图像。我正在使用http://today.java.net/pub/a/today/2007/03/27/navigable-image-panel.html

中的NavigableImagePanel

首先是我得到的结果 - Rotate and Resize

图像目前是顶部按钮附近的一个非常小的面板。这是BorderLayout.CENTER

NavigableImagePanel的代码:

http://pastebin.com/1wHRwMJU

和我的OpenImage.java代码:

import java.awt.*;
import java.awt.event.*;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;


public class OpenImage extends JFrame implements ActionListener{
/**
 * 
 */
private static final long serialVersionUID = 9066218264791891436L;
Image img;

public OpenImage() throws IOException{
    super("Resize and Rotate");

    setDefaultCloseOperation(EXIT_ON_CLOSE);
    BorderLayout grid = new BorderLayout(); 

    //this.setLayout(grid);
    setSize(900,700);
    setVisible(true);   


    //Row 1 holds some important buttons 
    //FlowLayout layout1 = new FlowLayout();
    //MigLayout mig = new MigLayout();
    JPanel row1 = new JPanel();
    //LayoutManager grid = new BoxLayout(row1, BoxLayout.X_AXIS);
    //row1.setLayout(grid);
    //row1.setLayout(BorderLayout.NORTH);
    //row1.setMaximumSize(new Dimension(100,100));
    BorderLayout border = new BorderLayout();
    //row1.setPreferredSize(new Dimension(0, 400));

    JButton open = new JButton ("Open");
    open.addActionListener(this);
    JButton rotate = new JButton("Rotate");
    rotate.addActionListener(this);
    JButton resize = new JButton("Resize");
    resize.addActionListener(this);
    JButton exit = new JButton ("Exit"); 
    exit.addActionListener(this);
    row1.add(open);
    row1.add(rotate);
    row1.add(resize);
    row1.add(exit);




    //This section has a workable picture panel, but it is too large. 
    //ImagePanel imagepanel = new ImagePanel();
    BorderLayout grid1 = new BorderLayout();
    Container cp = getContentPane();
    cp.setLayout(grid1);

    //add(row1);

    //JScrollPane row2 = new JScrollPane(imagepanel, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);


    BufferedImage img = ImageIO.read(new File("/home/adam/snow.jpg"));

    NavigableImagePanel imagepanel = new NavigableImagePanel(img);

    JPanel row2 = new JPanel();
    row2.add(imagepanel);
    //row2.repaint();
    JButton save = new JButton("Save");
    JPanel row3 = new JPanel();
    row3.add(save);

    cp.add(BorderLayout.NORTH, row1);
    cp.add(BorderLayout.CENTER, row2);
    cp.add(BorderLayout.SOUTH, row3);


}




public void actionPerformed(ActionEvent e) {
    String command = e.getActionCommand();
    if (command == "Exit"){
        System.exit(0);
    }
    if (command == "Open"){
        JFileChooser chooser = new JFileChooser();
        int returnVal = chooser.showOpenDialog(this);


    }
}



//This method below is now being deprecat


public static void main(String [] args){
    try {
        //UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
        UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");
    } catch (UnsupportedLookAndFeelException ex) {
        ex.printStackTrace();
    } catch (IllegalAccessException ex) {
        ex.printStackTrace();
    } catch (InstantiationException ex) {
        ex.printStackTrace();
    } catch (ClassNotFoundException ex) {
        ex.printStackTrace();
    }
    UIManager.put("swing.boldMetal", Boolean.FALSE);
    try {
        JFrame frame = new OpenImage();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

}

1 个答案:

答案 0 :(得分:5)

  1. 您在此处发布的代码错过了大量Java导入,无法在此处看到从Swing包导入的任何Java,并导入Image
  2. setVisible(true);必须是构造函数中的最后一行代码。
  3. 在所有情况下,setBackground()都可以帮助您找到任何问题。
  4. 在所有情况下,尝试使用pack()代替setSize(900,700);
  5. 由于我设置imagepanel.setPreferredSize(new Dimension(600, 400));,错误JComponents必须返回首选尺寸,然后pack()才能正常工作。
  6. 不知道从哪里获得此代码,因此几乎没有例外情况可以正常工作。
  7. 只是清理无用的混乱
  8. enter image description here

    来自代码

    import java.awt.BorderLayout;
    import java.awt.Color;
    import java.awt.Dimension;
    import java.awt.FlowLayout;
    import java.awt.Image;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import javax.swing.*;
    import javax.swing.border.LineBorder;
    
    public class OpenImage extends JFrame implements ActionListener {
    
        private static final long serialVersionUID = 9066218264791891436L;
        private Image img;
    
        public OpenImage() {
            super("Resize and Rotate");
    
            JButton open = new JButton("Open");
            open.addActionListener(this);
            JButton rotate = new JButton("Rotate");
            rotate.addActionListener(this);
            JButton resize = new JButton("Resize");
            resize.addActionListener(this);
            JButton exit = new JButton("Exit");
            exit.addActionListener(this);
    
            JPanel row1 = new JPanel();
            row1.setBackground(Color.red);
            row1.setLayout(new FlowLayout());
            row1.setBorder(new LineBorder(Color.black, 1));
            row1.add(open);
            row1.add(rotate);
            row1.add(resize);
            row1.add(exit);
    
            JPanel imagepanel = new JPanel();
            imagepanel.setLayout(new BorderLayout());
            imagepanel.setBackground(Color.blue);
            imagepanel.setBorder(new LineBorder(Color.black, 1));
            imagepanel.setPreferredSize(new Dimension(600, 400));
    
            JPanel row2 = new JPanel();
            row2.setLayout(new BorderLayout(10, 10));
            row2.setBorder(new LineBorder(Color.black, 1));
            row2.add(imagepanel, BorderLayout.CENTER);
            row2.setBackground(Color.red);
            JButton save = new JButton("Save");
    
            JPanel row3 = new JPanel();
            row3.setBorder(new LineBorder(Color.black, 1));
            row3.setBackground(Color.green);
            row3.setLayout(new FlowLayout());
            row3.add(save);
    
            setDefaultCloseOperation(EXIT_ON_CLOSE);
            setLayout(new BorderLayout(10, 10));
            add(BorderLayout.NORTH, row1);
            add(BorderLayout.CENTER, row2);
            add(BorderLayout.SOUTH, row3);
            pack();
            setVisible(true);
        }
    
        public void actionPerformed(ActionEvent e) {
            String command = e.getActionCommand();
            if (command == "Exit") {
                System.exit(0);
            }
            if (command == "Open") {
                JFileChooser chooser = new JFileChooser();
                int returnVal = chooser.showOpenDialog(this);
            }
        }
    
        public static void main(String[] args) {
          SwingUtilities.invokeLater(new Runnable() {
    
                @Override
                public void run() {
                    OpenImage openImage = new OpenImage();
                }
            });
        }
    }