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所以我有一个带有多个 JButtons 的绘图程序,我知道如何将该按钮与单击该按钮的动作相关联的唯一方法是执行类似 if (e.ActionCommand().equals("Label of the button here" ); 如果标签匹配,我知道我有正确的操作。但这是我的问题。我正在尝试将我的 JButtons 更改为图像,所以不是首先使用 JButton = new JButton("Hello"); 我正在尝试首先有 JButton = new JButton(new ImageIcon("c:/.....")) 然后有图像,这可行。但是我的问题是,在此之后我不知道如何引用按钮让它真正做点什么。谢谢!!!

import javax.imageio.ImageIO;
     import javax.swing.*;
     import javax.swing.border.Border;
     import javax.swing.border.LineBorder;

     import java.awt.*;
     import java.awt.event.*;
     import java.awt.image.BufferedImage;
     import java.io.File;
     import java.io.IOException;
     import java.util.*;


     public class PaintProgram extends JPanel implements MouseListener,ActionListener
     {
public static int stroke, eraser = 0;
private int xX1, yY1 , xX2, yY2, choice ;

public static void main(String [] args)
{
    new PaintProgram();
}

PaintProgram()
{


    JFrame frame = new JFrame("Paint Program");
    frame.setSize(1200, 800);
    frame.setBackground(Color.WHITE);
    frame.getContentPane().add(this);


    JMenuBar menuBar = new JMenuBar();
    frame.setJMenuBar(menuBar);
    JMenu help = new JMenu("Help");
    menuBar.add(help);
    JMenuItem about = new JMenuItem("About");
    help.add(about);
    about.addActionListener(this);



    JButton button1 = new JButton("Clear");
    button1.addActionListener(this);
    JButton color = new JButton("Color");
    color.addActionListener(this);
    JButton erase = new JButton("Erase?");
    erase.addActionListener(this);
    JButton button2 = new JButton("Empty Rect");
    button2.addActionListener(this);
    JButton button3 = new JButton("Filled oval");
    button3.addActionListener(this);
    JButton button4 = new JButton("Filled Rect");
    button4.addActionListener(this);
    JButton button5 = new JButton("Empty oval");
    button5.addActionListener(this);
    JButton button6 = new JButton("Line");
    button6.addActionListener(this);
    JRadioButton thin = new JRadioButton("Thin Line");
    thin.addActionListener(this);
    JRadioButton medium = new JRadioButton("Medium Line");
    medium.addActionListener(this);
    JRadioButton thick = new JRadioButton("Thick Line");
    thick.addActionListener(this);


    ButtonGroup lineOption = new ButtonGroup( );
    lineOption.add(thin);
    lineOption.add(medium);
    lineOption.add(thick);

   this.add(button1); 
   this.add(color);
   this.add(erase);
   this.add(button2);
   this.add(button3);
   this.add(button4);
   this.add(button5);
   this.add(button6);
   this.add(thin);
   this.add(medium);
   this.add(thick);
   addMouseListener(this);
   frame.setVisible(true);
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);



}

public void paintComponent(Graphics g)
{ 
     super.paintComponent(g);  
     Graphics2D g2 = (Graphics2D)g;
     if(grid == null){
        int w = this.getWidth();
        int h = this.getHeight();
        grid = (BufferedImage)(this.createImage(w,h));
        gc = grid.createGraphics();
        gc.setColor(Color.BLUE);
     }

     g2.drawImage(grid, null, 0, 0);
     check();
}
BufferedImage grid;
Graphics2D gc;


public void draw()
{
    Graphics2D g = (Graphics2D)getGraphics();
     int w = xX2 - xX1;
        if (w<0)
        w = w *(-1);

   int h = yY2-yY1;
        if (h<0)
        h=  h*(-1);

     switch(choice)
    {
        case 1:
            check();
            gc.drawRect(xX1, yY1, w, h);
            repaint();
            break;

        case 2:
            check();
            gc.drawOval(xX1, yY1, w, h);
            repaint();
            break;

        case 3:
            check();
            gc.drawRect(xX1, yY1, w, h);
            gc.fillRect(xX1, yY1, w, h);
            repaint();
            break;

        case 4:
            check();
            gc.drawOval(xX1, yY1, w, h);
            gc.fillOval(xX1, yY1, w, h);
            repaint();
            break;  

        case 5:

            if (stroke == 0)
            gc.setStroke(new BasicStroke (1));
            if (stroke == 1)
            gc.setStroke(new BasicStroke (3));
            if (stroke == 2)
            gc.setStroke(new BasicStroke (6));
            gc.drawLine(xX1, yY1, xX2, yY2);
            repaint();
            break;

        case 6:
            repaint();
            Color temp = gc.getColor();
            gc.setColor(Color.WHITE);
            gc.fillRect(0, 0, getWidth(), getHeight());
            gc.setColor(temp);
            repaint();
            break;   

        case 7:

            if (eraser == 1)
            {
                gc.clearRect(xX1, yY1, w, h);
            }
            else
            {

            }
            break;
    }
}

public void check()
{
    if (xX1 > xX2)
    {
        int z = 0;
        z = xX1;
        xX1 = xX2;
        xX2 =z;
    }
    if (yY1 > yY2)
    {
        int z = 0;
        z = yY1;
        yY1 = yY2;
        yY2 = z;
    }
}




public void actionPerformed(ActionEvent e)
{

if (e.getActionCommand().equals("Color"))
{
     Color bgColor
     = JColorChooser.showDialog(this,"Choose Background Color", getBackground());
   if (bgColor != null)
     gc.setColor(bgColor);
}


if (e.getActionCommand().equals("About"))
{
    System.out.println("About Has Been Pressed");
    JFrame about = new JFrame("About");
    about.setSize(300, 300);
    JButton picture = new JButton(new ImageIcon("C:/Users/TehRobot/Desktop/Logo.png"));
    about.add(picture);
    about.setVisible(true);
}

if (e.getActionCommand().equals("Empty Rect")) 
{         
  System.out.println("Empty Rectangle Has Been Selected~");
   choice = 1;

  }

if (e.getActionCommand().equals("Empty oval")) 
{         
 System.out.println("Empty Oval Has Been Selected!");
   choice = 2;
  }


if (e.getActionCommand().equals("Filled Rect"))
{         
  System.out.println("Filled Rectangle Has Been Selected");
   choice = 3;
  }


if (e.getActionCommand().equals("Filled oval")) 
{         
 System.out.println("Filled Oval Has Been Selected");
   choice = 4;
  }


if (e.getActionCommand().equals("Line"))
{
    System.out.println("Draw Line Has Been Selected");
    choice = 5;
}

if (e.getActionCommand().equals("Thin Line"))
{
    stroke = 0;
}

if (e.getActionCommand().equals("Medium Line"))
{
    stroke = 1;
}

if (e.getActionCommand().equals("Thick Line"))
{
    stroke = 2;
}

if(e.getActionCommand().equals("Erase?"))
{
    eraser = 1;
    choice = 7;
}

if (e.getActionCommand().equals("Clear"))
{         
    System.out.println("Clear All The Things!!!");
    choice = 6;
    draw();
}


 }

 public void mouseExited(MouseEvent evt){}
 public void mouseEntered(MouseEvent evt){}
 public void mouseClicked(MouseEvent evt){}
 public void mousePressed(MouseEvent evt)
 {

     xX1 = evt.getX();
     yY1= evt.getY();



   }
 public void mouseReleased(MouseEvent evt)
 {
     xX2 =evt.getX();
     yY2=evt.getY();
     draw();
     eraser = 0;
   }
4

3 回答 3

3

我会使用 ActionListener 并将事件注册到您的按钮,例如:

  yourButton.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent event)
    {// your logic here;
    }});

同样,这里是了解事件侦听器如何工作的一个很好的链接http://download.oracle.com/javase/tutorial/uiswing/events/index.html您尝试处理事件的方式使您的代码难以阅读和难以维护。

于 2011-09-28T20:46:44.050 回答
2

你有几种可能性:

  • 保持监听器代码不变,并调用setActionCommand每个按钮
  • 使用e.getSource()并测试源是button1还是button2等。
  • 为每个按钮使用一个单独的侦听器,如 Bartzilla 所示

最后一种方法通常是最好的方法,因为每个按钮都应该做一些与其他按钮不同的事情。为所有按钮使用一种巨大的方法,并带有很多if语句,这不是很干净。

此外,命名您的按钮fillOvalButtondrawLineButton等将使代码比使用 button1、button2 等更清晰。

于 2011-09-28T20:54:41.750 回答
0

如果你想在 JButton 上有一个 ImageIcon 和一种识别它的方法:

JButton b = new JButton(ImageIcon i, String name);

然后使用

JButton c = (JButton) e.getSource();
if (c.getText()).equals(name);

那是伪代码,但希望它有所帮助

于 2011-09-28T20:58:23.487 回答