dialogwindow.java

支持图形化界面GUI工具 有关JAVA 容器 监听类和 布局管理器的例子

import java.awt.*;
import java.awt.event.*;

public class DialogWindow extends Frame 
			  implements ActionListener {
   
    private SimpleDialog dialog;
    private TextArea textArea;
    String newline;

    public DialogWindow() {
        textArea = new TextArea(5, 40);
        textArea.setEditable(false);
        add("Center", textArea);
        Button button = new Button("打开对话框");
	    button.addActionListener(this);
        add("South", button);
		addWindowListener(new WindowAdapter() {
	    	public void windowClosing(WindowEvent e) {
		   		System.exit(0);
			}
		});

		newline = System.getProperty("line.separator");//获取行分隔符。
    }

    //响应点击"打开对话框"按钮。
    public void actionPerformed(ActionEvent event) {
        if (dialog == null) {
            dialog = new SimpleDialog(this, "A Simple Dialog");
        }
        dialog.setVisible(true);
    }

    //设置文本区textArea的内容 。
    public void setText(String text) {
        textArea.append(text + newline);
    }

    
    public static void main(String args[]) {
        DialogWindow window = new DialogWindow();
 
        window.setTitle("DialogWindow Application");
        window.pack();
        window.setVisible(true);
    }
}

//实现一个简单对话框的类。
class SimpleDialog extends Dialog implements ActionListener {
    TextField field;
    DialogWindow parent;
    Button setButton;

    SimpleDialog(Frame dw, String title) {
        super(dw, title, false);
        parent = (DialogWindow)dw;

        //创建标签与文本域。
	    Panel p1 = new Panel();
        Label label = new Label("请随意输入文字:");
        p1.add(label);
        field = new TextField(20);
	    field.addActionListener(this);  //响应用户回车操作。
	    p1.add(field);
        add("Center", p1);
       
        //创建两个按钮.
        Panel p2 = new Panel();
        p2.setLayout(new FlowLayout(FlowLayout.RIGHT));
        Button b = new Button("Cancel");
	    b.addActionListener(this);
        setButton = new Button("Set");
	    setButton.addActionListener(this);
        p2.add(b);
        p2.add(setButton);
        add("South", p2);

	//将对话框设置为最佳大小。
	    pack();
    }

    //响应点击两个按钮和文本域回车操作。
    public void actionPerformed(ActionEvent event) {
	    Object source = event.getSource();
        if ( (source == setButton)
           | (source == field)) {
            parent.setText(field.getText());
        }
        field.selectAll();
        setVisible(false);
    }
}