Question

JAVA设置左上角图标 和 背景色都不显示

public class FirstTry extends JFrame implements ActionListener{

private static final long serialVersionUID = 1L;

FirstTry.DrawCompent drawCompent = new DrawCompent();

private Toolkit kit = Toolkit.getDefaultToolkit();

private Image img = kit.getImage("ico2.gif");

public FirstTry(){
setTitle("WO");

setIconImage(img);

add(drawCompent);

setVisible(true);
setSize(300,300);
}

/** Draw the paint **/
private class DrawCompent extends JComponent{
public void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g;

double leftX = 100;
double leftY = 100;
double rightX = 200;
double rightY = 150;

Rectangle2D rect = new Rectangle2D.Double(leftX, leftY, rightX, rightY);
g2.setPaint(Color.blue);
g2.draw(rect);
DrawCompent drawCompent = new DrawCompent();
drawCompent.setBackground(SystemColor.window);

}

}

public static void main(String args[]){

FirstTry firstTry = new FirstTry();
firstTry.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e){
System.exit(0);

}

});

}

}

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Rectangle2D;

import javax.swing.*;



public class FirstTry extends JFrame{
   
    private static final long serialVersionUID = 1L;

    FirstTry.DrawCompent drawCompent = new DrawCompent();
    
    private Toolkit kit  = Toolkit.getDefaultToolkit();
    
    private Image img =  kit.getImage("D:\\眼泪知道\\图\\jpg小图标\\png-0001.jpg");//我这里设置得行啊   注意你的路径搞对没？
    
    public  FirstTry(){
        setTitle("WO");
    
        setIconImage(img);

        add(drawCompent);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//用这种方法关闭 资源
        setVisible(true);
        setSize(300,300);
        getContentPane().setBackground(Color.red);
    }

/** Draw the paint **/
    private class DrawCompent extends JComponent{
        public void paintComponent(Graphics g){
            Graphics2D g2 = (Graphics2D) g;
            
            int leftX = 100;
            int leftY = 100;
            int rightX = 200;
            int rightY = 150;
            
           // Rectangle2D rect = new Rectangle2D.Double(leftX, leftY, rightX, rightY);
            g2.setPaint(Color.blue);
            g2.fillRect(leftX,leftY, rightX, rightY);//绘制填充矩形  如果你真的想设置背景色 可以使用 setBackColor()
            DrawCompent drawCompent = new DrawCompent();
            drawCompent.setBackground(SystemColor.window);
            
        }
        
    }
    
    public static void main(String args[]){
        
        FirstTry firstTry = new FirstTry();
        //这里用这种方法关闭虚拟机不提倡   
//        firstTry.addWindowListener(new WindowAdapter() {
//            
//            public void windowClosing(WindowEvent e){
//                System.exit(0);
//                
//            }
//        
//        });
        
    }


    
}

追问

我是直接放在和java文件一个包下面的 不是用“xx.gif”吗？
g2.setBacground()是设置绘图的背景色吧，有办法设置整个窗口的背景色嘛？
谢谢了

追答

文件要放到工程目录下吧 ！ 你的意思是这种效果吗？

追问

是的刚运行了下发现了 0 0 然后用绝对路径也能显示图标了
只是头疼不知道相对路径怎么写- - 这个一直搞的头晕