java setLayout(null) 的错误
........
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
try
{
MainFrameTest frame = new MainFrameTest();
frame.setVisible(true);
} catch (Exception e)
{
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public MainFrameTest()
{
BackGroundPanel background_panel = new BackGroundPanel(1144, 712);
this.initComponents();
// this.initDate();
// setSize(1024, 789);
Toolkit toolkit = getToolkit(); // 不懂啊？怎么不是 new 呢？
Dimension dimension = toolkit.getScreenSize();
int screenHeight = dimension.height;
int screenWidth = dimension.width;
int frameHeight = this.getHeight();
int frameWidth = this.getWidth();
this.setLocation((screenWidth - frameWidth) / 2,
(screenHeight - frameHeight) / 2);
this.setComponentsPosition();
}.......
//////////////////////////////////////////////////////
private void setBackgroundSize()
{
int frameWidth = this.getWidth();
int frameHeight = this.getHeight();
int modifyFrameHeight = frameHeight - menuBar.getHeight() - 30;
//System.out.println("frameWdith = " + frameWidth);
//System.out.println("frameWidth = " + frameWidth);
//System.out.println("modifyFrameHeight = " + modifyFrameHeight);
background_panel.setBounds(0, 0, frameWidth, modifyFrameHeight);
}
private void initDate()
{
}
private void setComponentsPosition()
{
Component[] component = fastPanel.getComponents();
background_panel.setLayout(null);
fastPanel.add(background_panel, new Integer(Integer.MAX_VALUE)); // 将背景面板添加到原来的fastPanel面板上
this.setBackgroundSize();
for (int i = 0; i < component.length; i++)
{
fastPanel.remove(component[i]);
background_panel.add(component[i]);
component[i].setBounds(component[i].getX(), component[i].getY(),
component[i].WIDTH, component[i].getHeight());
}
}
////////////////////////////////////////////////////////////////////////////////
package com.MainFrame;
import java.awt.Graphics;
import javax.swing.ImageIcon;
import java.awt.Image;
import java.net.URL;
import javax.swing.JPanel;
public class BackGroundPanel extends JPanel
{
int height;
int width;
Image image;
public BackGroundPanel(int w, int h)
{
URL url = BackGroundPanel.class.getResource("/res/背景.jpg");
image = new ImageIcon(url).getImage();
this.initComponents(); // 调用类中的方法
this.height = h;
this.width = w;
}
public void setWidth(int w)
{
this.width = w;
}
public int getWidth()
{
return this.width;
}
public void setHeight(int h)
{
this.height = h;
}
public int getHeight()
{
return this.height;
}
protected void paintComponent(Graphics g) // 与paintComponent的区别
{
super.paintComponent(g);
Graphics g2 = (Graphics)g;
g2.drawImage(image, 0, 0, width, height, this);
}
private void initComponents()
{
setLayout(new java.awt.BorderLayout()); // 这个是神马意思呢
//this.paintComponent()
}
}
////////////////////////////////////////////////////////////////////////////////
package com.swtdesigner;
/*
public class SwingResourceManager
{
}
*/
import java.awt.Image;
import java.awt.Toolkit;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Iterator;
import javax.swing.ImageIcon;
/**
* Utility class for managing resources such as colors, fonts, images, etc.
*
* This class may be freely distributed as part of any application or plugin.
* <p>
* Copyright (c) 2003 - 2004, Instantiations, Inc. <br>All Rights Reserved
*
* @author scheglov_ke
*/
public class SwingResourceManager {
/**
* Maps image names to images
*/
private static HashMap<String, Image> m_ClassImageMap = new HashMap<String, Image>();
/**
* Returns an image encoded by the specified input stream
* @param is InputStream The input stream encoding the image data
* @return Image The image encoded by the specified input stream
*/
private static Image getImage(InputStream is) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte buf[] = new byte[1024 * 4];
while (true) {
int n = is.read(buf);
if (n == -1)
break;
baos.write(buf, 0, n);
}
baos.close();
return Toolkit.getDefaultToolkit().createImage(baos.toByteArray());
} catch (Throwable e) {
return null;
}
}
/**
* Returns an image stored in the file at the specified path relative to the specified class
* @param clazz Class The class relative to which to find the image
* @param path String The path to the image file
* @return Image The image stored in the file at the specified path
*/
public static Image getImage(Class<?> clazz, String path) {
String key = clazz.getName() + '|' + path;
Image image = m_ClassImageMap.get(key);
if (image == null) {
if ((path.length() > 0) && (path.charAt(0) == '/')) {
String newPath = path.substring(1, path.length());
image = getImage(new BufferedInputStream(clazz.getClassLoader().getResourceAsStream(newPath)));
} else {
image = getImage(clazz.getResourceAsStream(path));
}
m_ClassImageMap.put(key, image);
}
return image;
}
/**
* Returns an image stored in the file at the specified path
* @param path String The path to the image file
* @return Image The image stored in the file at the specified path
*/
public static Image getImage(String path) {
return getImage("default", path); //$NON-NLS-1$
}
/**
* Returns an image stored in the file at the specified path
* @param section String The storage section in the cache
* @param path String The path to the image file
* @return Image The image stored in the file at the specified path
*/
public static Image getImage(String section, String path) {
String key = section + '|' + SwingResourceManager.class.getName() + '|' + path;
Image image = m_ClassImageMap.get(key);
if (image == null) {
try {
FileInputStream fis = new FileInputStream(path);
image = getImage(fis);
m_ClassImageMap.put(key, image);
fis.close();
} catch (IOException e) {
return null;
}
}
return image;
}
/**
* Clear cached images in specified section
* @param section the section do clear
*/
public static void clearImages(String section) {
for (Iterator<String> I = m_ClassImageMap.keySet().iterator(); I.hasNext();) {
String key = I.next();
if (!key.startsWith(section + '|'))
continue;
Image image = m_ClassImageMap.get(key);
image.flush();
I.remove();
}
}
/**
* Returns an icon stored in the file at the specified path relative to the specified class
* @param clazz Class The class relative to which to find the icon
* @param path String The path to the icon file
* @return Icon The icon stored in the file at the specified path
*/
public static ImageIcon getIcon(Class<?> clazz, String path) {
return getIcon(getImage(clazz, path));
}
/**
* Returns an icon stored in the file at the specified path
* @param path String The path to the icon file
* @return Icon The icon stored in the file at the specified path
*/
public static ImageIcon getIcon(String path) {
return getIcon("default", path); //$NON-NLS-1$
}
/**
* Returns an icon stored in the file at the specified path
* @param section String The storage section in the cache
* @param path String The path to the icon file
* @return Icon The icon stored in the file at the specified path
*/
public static ImageIcon getIcon(String section, String path) {
return getIcon(getImage(section, path));
}
/**
* Returns an icon based on the specified image
* @param image Image The original image
* @return Icon The icon based on the image
*/
public static ImageIcon getIcon(Image image) {
if (image == null)
return null;
return new ImageIcon(image);
}
}
