java中对话框例子的讲解

源代码参考：

package optionDialog;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Component;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.geom.Rectangle2D;

import java.util.Date;

import javax.swing.*;

public class OptionDialog {

public static void main(String[] args) {

OptionDialogFrame odf=new OptionDialogFrame();

odf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

odf.setVisible(true);

odf.setTitle("OptionDialogFrame");

}

}

class OptionDialogFrame extends JFrame{

private ButtonPanel typePanel;

private ButtonPanel messageTypePanel;

private ButtonPanel messagePanel;

private ButtonPanel confirmPanel;

private ButtonPanel optionsPanel;

private ButtonPanel inputPanel;

private String messageString = "Message";

private Icon messageIcon = newImageIcon("blue-ball.gif");

private Object messageObject = new Date();

private Component messageComponent = newSampleComponent();

public OptionDialogFrame(){

JPanel gridPanel=new JPanel();

gridPanel.setLayout(new GridLayout(2,3));

typePanel=newButtonPanel("Type","Message","Confirm","Option","Input");

messageTypePanel=new ButtonPanel("MessageType","ERROR_MESSAGE","INFORMATION_MESSAGE","WATNING_MESSAGE","QUESTION_MESSAGE","PLAIN_MESSAGE");

messagePanel=newButtonPanel("Message","String","Icon","Component","Other","Object[]");

confirmPanel=newButtonPanel("Confirm","DEFAULT_OPTION","YES_NO_OPTION","YES_NO_CANCEL_OPTION","OK_CANCEL_OPTION");

optionsPanel=newButtonPanel("Option","String[]","Icon[]","Object[]");

inputPanel=new ButtonPanel("Input","Text field","Combobox");

gridPanel.add(typePanel);

gridPanel.add(messageTypePanel);

gridPanel.add(messagePanel);

gridPanel.add(confirmPanel);

gridPanel.add(optionsPanel);

gridPanel.add(inputPanel);

JPanel showPanel=new JPanel();

JButton showButton=new JButton("Show");

showButton.addActionListener(new ShowAction());

showPanel.add(showButton);

add(gridPanel,BorderLayout.CENTER);

add(showPanel,BorderLayout.SOUTH);

pack();

}

  public Object getMessage()

  {

     Strings = messagePanel.getSelection();

     if(s.equals("String")) return messageString;

     elseif (s.equals("Icon")) return messageIcon;

     elseif (s.equals("Component")) return messageComponent;

     elseif (s.equals("Object[]")) return new Object[] { messageString,messageIcon,

         messageComponent, messageObject };

     elseif (s.equals("Other")) return messageObject;

     elsereturn null;

  }

 

  public Object[] getOptions()

  {

     Strings = optionsPanel.getSelection();

     if(s.equals("String[]")) return new String[] { "Yellow", "Blue","Red" };

     elseif (s.equals("Icon[]")) return new Icon[] { newImageIcon("yellow-ball.gif"),

          newImageIcon("blue-ball.gif"), new ImageIcon("red-ball.gif") };

     elseif (s.equals("Object[]")) return new Object[] { messageString,messageIcon,

         messageComponent, messageObject };

     elsereturn null;

  }

 

  public int getType(ButtonPanel panel)

  {

     Strings = panel.getSelection();

    try

    {

       returnJOptionPane.class.getField(s).getInt(null);

    }

     catch(Exception e)

    {

       return -1;

    }

  }

 

  private class ShowAction implementsActionListener

  {

     publicvoid actionPerformed(ActionEvent event)

    {

       if (typePanel.getSelection().equals("Confirm"))JOptionPane.showConfirmDialog(

            OptionDialogFrame.this, getMessage(), "Title",getType(confirmPanel),

            getType(messageTypePanel));

       else if(typePanel.getSelection().equals("Input"))

       {

          if(inputPanel.getSelection().equals("Text field"))JOptionPane.showInputDialog(

              OptionDialogFrame.this, getMessage(), "Title",getType(messageTypePanel));

          elseJOptionPane.showInputDialog(OptionDialogFrame.this, getMessage(),"Title",

              getType(messageTypePanel), null, new String[] {"Yellow", "Blue", "Red" },

              "Blue");

       }

       else if(typePanel.getSelection().equals("Message"))JOptionPane.showMessageDialog(

            OptionDialogFrame.this, getMessage(), "Title",getType(messageTypePanel));

       else if(typePanel.getSelection().equals("Option"))JOptionPane.showOptionDialog(

            OptionDialogFrame.this, getMessage(), "Title",getType(confirmPanel),

            getType(messageTypePanel), null, getOptions(),getOptions()[0]);

    }

  }

}

class SampleComponent extends JComponent

{

  public void paintComponent(Graphicsg)

  {

    Graphics2D g2 = (Graphics2D) g;

    Rectangle2D rect = new Rectangle2D.Double(0, 0,getWidth() - 1, getHeight() - 1);

    g2.setPaint(Color.YELLOW);

    g2.fill(rect);

    g2.setPaint(Color.BLUE);

    g2.draw(rect);

  }

  public Dimension getPreferredSize()

  {

     returnnew Dimension(10, 10);

  }

}

class ButtonPanel extends JPanel{

private ButtonGroup group;

public ButtonPanel(String title,String... options){

setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(),title));

//设置单个面板内的组件垂直

setLayout(new BoxLayout(this,BoxLayout.Y_AXIS));

group=new ButtonGroup();

for (String option: options) {

JRadioButton b=new JRadioButton(option);

b.setActionCommand(option);

add(b);

group.add(b);

b.setSelected(option==options[0]);

}

}

public String getSelection(){

return group.getSelection().getActionCommand();

}

}