JPanel,JFrame 设置背景图片？？？

Question

JButton JLabel 上能只设置图片，不要文字
方法是
  setText()方法

Answer 1

和jButton1.setIcon(new ImageIcon(new java.net.URL("file:///D:/Documents and Settings/My Documents/18.gif")));

Answer 2

重载paint()方法，我以前贴过怎么写

Answer 3

能够加载背景图了
但是出现新问题，加了背景图后，原先定位在JFrame上的控件不能显示，比如JButton JLabel----JButton要在上面点击一下才能显示出来，为什么？？

Answer 4

请看代码：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class applet3  extends JFrame 
{
Image img1;
MediaTracker mt;
Container contentPanel=this.getContentPane();public applet3() {
this.setSize(400,300);
this.setResizable(false);
this.setLocation(this.getToolkit().getScreenSize().width/2-this.getWidth()/2,this.getToolkit().getScreenSize().height/2-this.getHeight()/2);


img1=this.getToolkit().getImage("1.jpg");
mt=new MediaTracker(this);
mt.addImage(img1,0);
ImageIcon icon=new ImageIcon("4.jpg");
contentPanel.setLayout(null);
  JButton button=new JButton(icon);
  JLabel label=new JLabel(icon);
  button.setBounds(0,0,80,30);
  label.setBounds(90,90,80,50);
  contentPanel.add(label);
  contentPanel.add(button);

this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
this.setVisible(true);
}public void paint(Graphics g) {
 super.paint(g);
          g.drawImage(img1,0,0,this.getWidth(),this.getHeight(),this);
    
}public static void main(String args[]) {
    new applet3();
}
}出现的效果是：先看到两个控件button label，然后出现背景图片，背景图片将控件覆盖，就只能看见背景图片？？？不知道怎么解决，还请大虾门多帮忙！！~~~

Answer 5

paint()里顺序写反了，应该是
public void paint(Graphics g) {
          g.drawImage(img1,0,0,this.getWidth(),this.getHeight(),this);
          super.paint(g);
}
而且我建议你重载JPanel而不是JFrame，因为JFrame的paint()可能比较复杂，如果其中又重写了背景，那你的drawimage就给覆盖回去了，而JPanel我做过，没有问题

Answer 6

谢谢  Apocalypse(逍遥思辨) 拉~！解决了
代码如下：
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;public class JPanelTemp extends JFrame
{
public JPanelTemp()
{
Container con=this.getContentPane();
con.setLayout(null);
ImagePanel panelTemp=new ImagePanel("chess.jpg");
panelTemp.setBounds(100,0,600,500);
con.add(panelTemp);
this.addWindowListener (new WindowAdapter(){
public void windowClosing(WindowEvent e){
dispose();
System.exit(0);
}
});
}

public static void main(String args[])
{
System.out.println("Starting App");
JPanelTemp f = new JPanelTemp();
f.setBounds(0,0,800,600);
f.show();
}
}class ImagePanel extends JPanel implements ActionListener
{
    private String strPicName;
    ImageIcon white=new ImageIcon("white.jpg");
    public ImagePanel(String strName)
    {
        strPicName = strName;
     this.setLayout(null);
     
     JButton button=new JButton(white);
     //JLabel label=new JLabel();
     button.setBounds(0,0,30,20);
     button.setFocusPainted(false); 
    button.setBorderPainted(false); 
    button.setContentAreaFilled(false); 
    button.setMargin(new Insets(0,0,0,0));
     //label.setBounds(120,80,80,50);
     //label.addActionListener(this);
     add(button);
     //add(label);
    }
    
    public void paintComponent(Graphics g)
    {
        loadPic(strPicName,g);
    }
    
      public void loadPic(String picName,Graphics g)
     {
          ImageIcon img=new ImageIcon(picName);
          int pWidth=this.getWidth();
          int pHeight=this.getHeight();
          int mWidth=img.getIconWidth() ;
          int mHeight=img.getIconHeight() ;
          int x,y;
          int width,height;
          if((mWidth<=pWidth)&&(mHeight<=pHeight)){
             x=(pWidth-mWidth)/2;    y=(pHeight-mHeight)/2;
             width=mWidth;   height=mHeight;
          }else {
             width=pWidth;   height=pHeight;
            float widthScale=(float)pWidth/(float)mWidth;            float heightScale=(float)pHeight/(float)mHeight;
            if(widthScale<heightScale)
                height=(int)(mHeight*widthScale);
            else
                width=(int)(mWidth*heightScale);
             x=(pWidth-width)/2;
             y=(pHeight-height)/2;
          }
         //statusBar.setText("文件:"+ this +"    大小:"+mWidth+"X"+mHeight);
         g.clearRect(0,0,pWidth,pHeight);
         g.drawImage(img.getImage(),x,y,width,height,this);
    }
    public void actionPerformed(ActionEvent e)
    {
     //if(e.getSource()==label)
    {
    
    }
    }
}