该代码画了一个按钮
Button(“ok”)创建了一个有显示“ok”的按钮
Button()是构造函数
按钮属于容器
第1题:
下列程序在Frame中设定BorderLayout布局管理器,选择正确的语句填入程序的横线处。 import java.awt.*; public class ex43 extends Frame { public static void main(String[] args) { ex43 bj = new ex43("BorderLayout"); ______ obj.add("North", new Button("North")); obj.add("South", new Button("Sourth")); obj.add("East", new Button ("East")); obj.add("West", new Button ("West")); obj. add ("Center", new Button ( "Center" ) ); obj.pack(); obj. setVisible (true); } public ex43(String str) { super (str); } }
A.obj.setLayout(new BorderLayout());
B.setLayout(new Borderkayout());
C.setLayout(BorderLayout());
D.obj.setLayout(BorderLayout());
第2题:
下面程序代码,让用户输入想显示的.gif文件名,之后将这个图像文件加载到内存并显示。请勿改动原有代码,在下画线处填人适当浯句,将程序补充完整。
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class test20_2 extends Applet implements ActionListener {
Label promptLbl=new Label(“请输入欲显示的图像文件名:”);
TextField inputTfd=new TextField20( );
Button getlmageBtn=new Button(“显示图像”);
Image mylmage;
public void init( ) {
add(promptLbl);
add(inputTfd);
add(getlmageBtn);
inputTfd.setText(””);
getlmageBtn.addActionListener(this);
}
public void paint(Graphics g) {
if(mylmage!=null)
g.______(mylmage,10,100,this);
}
public void actionPerformed(ActionEvent ae) {
if(ae.getSource( )==_______) {
String str=inputTfd.getText( ).trim( );
if(!(str.substring(Math.max(0,str.length( )-4)).equals(".gif")))
str=str.trim( )+".gif";
mylmage=getlmage(getDocumentBase( ),str);
repaint( );
}
}
}
第3题:
以下程序中,当用户单击“移动”按钮以后,就可以使用方向键控制屏幕上句子的移动,单击“停止”按钮,则句子不再随着方向键移动。运行结果如下图所示
注意:请勿改动其他已有语句内容,仅在横线处填入适当语句。
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Example2_8 extends Applet implements KeyListener
{
public void keyTyped(KeyEvent e) {}
public void keyReleased(KeyEvent e) {}
Button button;
Button stopButton;
Label out;
int x,y;
public void _______ ()
{
button = new Button("移动");
button.addActionListener(new AddMoveListener(this));
stopButton = new Button("停止移动");
stopButton.addActionListener(new RemoveListener(this));
stopButton.setEnabled(false);
out = new nabel("按下按钮以后我可以随方向键移动");
add(button);
add(stopButton);
add (out);
}
public void start()
{
super, start ();
}
public void keyPressed(KeyEvent e)
{
x=out.getBounds().x;
y=out.getBounds().y;
if(e.getKeyCode()==KeyEvent.VK_UP)
{
y=y-2;
if(y<=0) y=0;
out. setLocation (x, y);
}
else if(e.getKeyCode()==KeyEvent.VK_DOWN)
{
y=y+2;
if (y>=300) y=300;
out. setLocation (x, y);
}
else if(e.getKeyCode()==KeyEvent.VK_LEFT)
{
x=x-2;
if(x<=0) x=0;
out. setLocation (x, y);
}
else if(e.getKeyCode()==KeyEvent.VK_RiGHT)
{
第4题:
下面程序构造了一个Swing Applet,在下画线处填入正确的代码。
import javax.swing.*;
import java.awt.*;
public class SwingApplet extends ______ {
JLabel 1=new JLabel("This is a Swing Applet.");
public void init() {
Container contentPane=getContentPane();
contentPane.add(1);
}
}
第5题:
import java.awt.*; import java.applet.*; public class ButtonDemo extends Applet{ public void init() { Button pushBotton=new Button(“ok”); Button downBotton=new Button(“Yes”); add(pushBotton); add(downBotton); } } 根据以上代码,下列结束正确的是()
第6题:
What will be the appearance of an applet with the following init() method? public void init() { add(new Button("hello")); }
第7题:
Given the following code, which code fragments, when inserted at the indicated location, will succeed in making the program display a button spanning the whole window area?() import java.awt.*; public class Q1e65 { public static void main(String args[]) { Window win = new Frame(); Button but = new Button("button"); // insert code fragment here win.setSize(200, 200); win.setVisible(true); } }
第8题:
import java.awt.*; public class Test extends Frame { public Test() { add(new Label(“Hello”) ); add(new TextField(“Hello”) ); add(new Button(“Hello”) ); pack(); show(); } public static void main(String args) { new Test (); } } What is the result? ()
第9题:
该代码画了一个按钮
Button(“ok”)创建了一个有显示“ok”的按钮
Button()是构造函数
按钮属于容器
第10题:
该代码画了一个按钮
Button(ok)创建一个有显示ok的按钮
Button()是构造函数
按钮属于容器
第11题:
Nothing appears in the applet.
A button will cover the whole area of the applet.
A button will appear in the top left corner of the applet.
A button will appear, centered in the top region of the applet.
A button will appear in the center of the applet.
第12题:
All the buttons change height if the frame height is resized.
All the buttons change width if the Frame width is resized.
The size of the button labeled “One” is constant even if the Frame is resized.
Both width and height of the button labeled “Three” might change if the Frame is resized.
第13题:
下列程序采用BorderLayout布局管理,选择正确的语句填入横线处,实现在North区域显示一个名字为“北方”的Button构件。 import java.awt.*; public class ex48 { public static void main(String[] args) { frame. frm = new Frame. ("北方"); frm.setLayout(new BorderLayout()); frm.setSize(200, 200); frm.setVisible(true); } }
A.add("Nouth", new Button("北方"));
B.frm.add("South", new Button("北方"));
C.frm.add("Nouth", new Button("北方"));
D.Frm.add("South", Button("北方"));
第14题:
下列Applet在窗口中放置2个Button,标签分别为“东”和“西”,在窗口中的位置与它们的名字相同。选择正确的语句填入横线处。 import java.awt.*; import java.applet.*; public class ex16 extends Applet { Button e, w; public void init() { e = new Button("东"); w = new Button("西"); add("East", e); add("West", w); } }
A.setLayout(new BoxLayout());
B.setLayout(new FlowLayout());
C.setLayout(new BorderLayout());
D.setLayout(new GridLayout());
第15题:
本题是一个Applet,功能是监听用对于文本域中文本的选择。页面中有一个文本域、一个“复制”按钮和一个文本框,选中文本域中部分文字后,单击按钮“复制”,所选文字将显示在文本框中。 import java.applet.Applet; import java.awt.*; import java.awt.event.*; public class java3 extends Applet implements ActionL- istener { TextArea ta=new TextArea(5,30); TextField tf=new TextField(30); Button button=new Button("复制"); String text="AWT提供基本的GUl组件,\n"+" 具有可以扩展的超类,\n"+"它们的属性是继承的。\ n": public void init { setLayout(new FlowLayout(FlowLayout.left)); ta.setText(text); ta.setEditable(true); add(ta); add(button); add(tf); ta.addActionListener(this); } public void actionPerformed(ActionEvent e) { String S; s=ta.getSelectText; if(e.getSource= =button) tf.setText(s); } }
第16题:
下列Applet用于显示提供它的主机的IP地址。请选择正确的语句填入横线处。 import java.awt.*; import java. awt. event.*; import java.applet.Applet; import java.net. *; public class ex23 extends Applet { public void init() { setLayout(new GridLayout(2, 1); Button btm = new Button("显示IP"); final Label 1 = new Label(" "); btn. addActionListener (new ActionListener ( ) { public void actionPerformed(ActionEvent ae) { try { URL ur1 = getCodeBase(); String strName = ur1.getHost(); ______ 1.setText (ia.toString()); } catch (Exception e) { e.printStackTrace (); } } }); add (btn); } }
A.InetAddress ia = URL.getByName(strName);
B.InetAddress ia = InetAddress.getByName(strName);
C.InetAddress ia = new InetAddress.getByName(strName);
D.InetAddress ia = InetAddress.getByName(ur1);
第17题:
import java.awt.*; import java.applet.*; public class ButtonDemo extends Applet{ public void init() { Button pushBotton=new Button("ok"); Button downBotton=new Button("Yes"); add(pushBotton); add(downBotton); } } 根据以上代码,下列解释正确的是()。
第18题:
import java.awt.*; import java.applet.*; public class ButtonDemo extends Applet{ public void init(){ Button pushButton=new Button(“ok”); Button downButton=new Button(“Yess”); add(pushButton); add(downButton); } } 根据以上代码,下列解释正确的是()
第19题:
import java.awt.*; public class X extends Frame { public static void main (String args) { X x = new X(); x.pack(); x.setVisible(true); } public X() { setLayout (new BordrLayout()); Panel p = new Panel (); add(p, BorderLayout.NORTH); Button b = new Button (“North”); p.add(b): Button b = new Button (“South”); add(b1, BorderLayout.SOUTH): } } Which two statements are true?()
第20题:
import java.awt*; public class X extends Frame ( public static void main(string args) ( X x = new X (); X.pack(); x.setVisible(true); ) public X () ( setlayout (new GridLayout (2,2)); Panel p1 = new panel(); Add(p1); Button b1= new Button (“One”); P1.add(b1); Panel p2 = new panel(); Add(p2); Button b2= new Button (“Two”); P2.add(b2); Button b3= new Button (“Three”); add(b3); Button b4= new Button (“Four”); add(b4); ) ) Which two statements are true? ()
第21题:
该代码画了一个按钮
Button(“ok”)创建一个有显示”ok”的按钮
Button()是构造函数
按钮属于容器
第22题:
The buttons labeled “North” and “South” will have the same width.
The buttons labeled “North” and “South” will have the same height.
The height of the button labeled “North” can very if the Frame is resized.
The height of the button labeled “South” can very if the Frame is resized.
The width of the button labeled “North” is constant even if the Frame is resized.
The width of the button labeled “South” is constant even if the Frame is resized.
第23题:
win.setLayout(new BorderLayout()); win.add(but);
win.setLayout(new GridLayout(1, 1)); win.add(but);
win.setLayout(new BorderLayout()); win.add(but, BorderLayout.CENTER);
win.add(but);
win.setLayout(new FlowLayout()); win.add(but);
第24题:
The code will not compile.
A Window will appear containing only a Button.
An IllegalArgumentException is thrown at line 6.
A Window button will appear but will not contain the Label, TextField, or Button.
A Window will appear containing a Label at the top, a TextField below the Label, and a Button below the TextField.
A Window will appear containing a Label on the left, a TextField to the right of the Label, and a button to the right of the TextField.