成员函数GetDocument()的作用是()
A.获取视图类指针
B.获取文档类指针
C.获取框架窗口指针
D.获取对话框指针
A.获取视图类指针
B.获取文档类指针
C.获取框架窗口指针
D.获取对话框指针
第1题
A.getDocument()
B.getApplets()
C.getApplet(String name)
D.getAppletList()
第2题
import java.awt.*;
import java.awt.event*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
public class java3
{
public static void main(String[]args)
{
TextTestFrame. frame=new TextTestFrame():
frame.setDefauhCloseOperation(JFrame.EXIT_
0N_CLOSE);
frame.show();
}
}
class TextTestFrame. extends JFrame
{
public TextTestFrame()
{
setTitle("java3"):
setSize(DEFAULT_WIDTH,DEFAULT_
HElGHT);
Container contentPane=getContentPane();
DocumentListener listener=new DoeumentListen-
er();
JPanel panel=new JPanel();
hourField=new JTextField("12",3);
panel.add(hourField);
hourField.getDocument().addDocumentListener
(this);
minuteField=new JTextField("00",3):
panel.add(minuteField);
minuteField.getDocument().addDocumentListener
(listener);
contentPane.add(panel,BorderLayout.S()UTH);
clock=new ClockPanel();
contentPane.add(clock,BorderLayout.CEN-
TER);
}
public void setClock()
{
try
{
int hours
=Integer.parseInt(hourField.getText().trim
()):
int minutes
=Integer.parseInt(minuteField.getText().trim
());
clock.setTime(hours,minutes);
}
catch(NumberFormatExcepfion e){}
}
public static final int DEFAULT_WIDTH=300;
public static final int DEFAULT_HEIGHT
=300;
private J TextField hourField;
private JTextField minuteField;
private ClockPanel clock;
private class clockFieldListener extends Docu-
mentListener
{
public void insertUpdate(DocumentEvent e){ set-
Clock();}
public void removeUpdate(DocumentEvent e){
setClock();}
public void changedUpdate(DocumentEvent e){}
}
}
class ClockPanel extends JPanel
{
pubhc void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphies2D g2=(Graphics2D)g;
Ellipse2D circle
=new Ellipse2D.Double(0,0,2* RADIUS,2
*RADIUS);
g2.draw(circle);
double hourAngle
=Math.toRadians(90-360*minutes/(12
*60));
drawHand(92,hourAngle,HOUR_HAND_
LENGTH);
double minuteAngle
=Math.toRadians(90-360*minutes/60);
drawHand(g2,minuteAngle,MINUTE_HAND_
LENGTH):
}
punic void drawHand(Graphics2D g2,
double angle,double handLength)
{
Point2D end=new Point2D.Double(
RADIUS+handLength*Math.cos(angle),
RADIUS-handLength*Math.sin(angle));
Point2D center=new Point2D.Double(RADIUS,
RADIUS):
g2.draw(new Line2D.Double(center,end));
}
public void setTime(int h,int m)
{
minutes=h*60+m;
repaint();
}
private double minutes=0;
private double RADIUS=100;
private double MINUTE_HAND_LENGTH=
0.8*RADIUS;
private double HOUR_HAND_LENGTH=0.6
*RADIUS:
}
第7题
A、是否相对父组件在垂直方向上居中
B、是否相对父组件水平方向上居中
C、是否相对父组件在水平和垂直方向上均居中
D、是否相对某一平级组件在水平和垂直方向上均居中
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