更多"本题的功能是监听对于颜色的复制和粘贴。程序窗口中,有一个颜色设置框和两"的相关试题:
[填空题]本题的功能是监听对于菜单项和工具条的操作。窗口中有一个菜单“Color”和一个工具体,菜单“Color”中有菜单项“Yellow”、“Blue”、“Red”和“Exit”,每个菜单项都有对应的图形,单击前三个颜色菜单项,主窗口就变成对应的颜色,单击“Exit”则退出程序。工具条上有4个按钮,分别为三个颜色按钮和一个退出程序的按钮,单击任意一个颜色按钮,主窗口将变成按钮对应的颜色,单击退出程序按钮,则退出程序。
import java. awt. * ;
import java. awt. event. * ;
import java. beans. * ;
import javax. swing. * ;
public class java3
public static void main(String[] args)
ToolBarFrame frame=new ToolBarFrame( );
frame. setDefaultCloseOperation (JFrame. EXIT_ON CLOSE);
frame. show( );
class ToolBarFrame extends JFrame
public ToolBarFrame( )
setTitle("java3");
setSize (DEFAULT_WIDTH, DEFAULT_HEIGHT);
Container contentPane=getContentPane( );
panel=new JPanel( );
contentPane. add(panel, BorderLayout. CENTER);
Action blueAction=new ColorAction("Blue",
new Imagelcon("java3-blue--ball. gif"), Color.BLUE);
Action yellowAction=new ColorAction ("Yellow",
new Imagelcon("jav
[简答题]本题的功能是监听对于列表项的操作。窗口中有一个列表和三个按钮“添加”、“删除”和“关闭”。单击“添加”按钮,则会在当前所选列表项后添加一个名为“新增表项”的列表项,同时后台输入列表中的表项数量。单击“删除”按钮后,如果未选中表项,则弹出提示消息框“请选择表项”。否则将选中的表项删除,同时后台输出删除表项的内容和列表中的表项数量。单击“关闭”按钮退出程序。
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;
public class java3
public static void main(String args[])
final Frame frmFrame=new Frame( );
Panel pnlPanel1=new Panel( );
Panel pnlPanel2=new Panel( );
final List lstList=new List(8);
for(int i=0;i<10;i++)
String strName="表项"+(new Integer(i+1)).toString( );
lstList.add(strName);
Button btnButton1=new Button("添加");
Button btnButton2=new Button("删除");
Button btnButton3=new Button("关闭");
btnButton1.addActionListener(new ActionListener( )
public void actionPerformed(ActionEvent e)
lstList.add("新增表项",lstList.getSelected( )+1);
System.out.println("列表中的表项数量:"+lstList.getItemCount( ));
);
bt
[简答题]本题程序的功能是监听对于列表项的操作。窗口中有一个列表和“添加”、“删除”和“关闭”三个按钮。单击“添加”按钮,会在当前所选列表项后添加一个名为“新增表项”的列表项,同时后台输入列表中的表项数量。单击“删除”按钮,如果未选中表项,则弹出提示消息框“请选择表项”,否则将选中的表项删除,同时后台输出删除表项的内容和列表中的表项数量。单击“关闭”按钮退出程序。程序中存在若干错误,请找出并改正(注意:不得改动程序的结构,不得增行或删行)。
import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;
public class advance
public static void main(String args[])
final Frame frmFrame = new Frame( );
Panel pnlPanel1 = new Panel( );
Panel pnlPanel2 = new Panel( );
final List istList = new List(8);
for(int i = 0; i <10; i++)
String strName = "表项" + (new Integer(i+1)).toString( );
istList.add( strName );
Button btnButton1 = new Button("添加");
Button btnButton2 = new Button("删除");
Button btnButton3 = new Button("关闭");
btnButton1.addActionListener( new ActionListener( )
publiC void actionPerformed(ActionEvent e)
lstList.add("新增表项",istList.getSelected( )+1);
System.out.println("列表中
[填空题]本题的功能是监听键盘键的敲击,并显示在窗口中。
import javax. swing. * ;
import java. awt. * ;
import java. awt. event. * ;
public class java3 extends JFrame extends KeyListener
private String line1="", line2="";
private String line3="";
private JTextArea textArea;
public java3( )
super("java3");
textArea=new JTextArea(10,15);
textArea, setText("Press any key on the key-board... ");
textArea, setEnabled(false);
addKeyListener(this);
getContentPane( ). add(textArea);
setSize(350,100);
show( );
public void keyPressed(KeyEvent e)
lind="Key pressed:"+e. getKeyText(e. getKeyCode( ));
setLines2and3(e);
public void keyReleased(KeyEvent e)
line1="Key released:"+e. getKeyText(e. getKeyCode( ));
setLines2and3(e);
public void keyTyped(KeyEvent e)
Lind="Key typed:"+e. getKeychar( );
setLines2and3(e);
private void setLines2and3
[简答题]本题的功能是监听键盘键的敲击,并显示在窗口中。
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class java3 extends JFrame extends KeyListener
private String linel="",line2="";
private String line3="";
private JTextArea textArea;
public java3( )
super("java3");
textArea=new JTextArea(10,15);
textArea.setText("Press any key on the keyboard...");
textArea.setEnabled(false);
addKeyListener(this);
getContentPane( ).add(textArea);
setSize(350,100);
show( );
public void keyPressed(KeyEvent e)
line1="Key pressed:"+e.getKeyText(e.getKeyCode( ));
setLines2and3(e);
public void keyReleased(KeyEvent e)
linel="Key released:"+e.getKeyText(e.getKeyCode( ));
setLines2and3(e);
public void keyTyped(KeyEvent e)
Line1="Key typed:"+e.getKeychar( );
setLines2and3(e);
private void setLines2and3(KeyEvent e)
<
[填空题]本题的功能是监听键盘敲击事件,并将敲击的字符显示在标签上。开始,文字标签提示“Please press your keyboard!”,当按下键盘上的字符键,文字标签就变为“’*’is pressed!”(*为所按字母)。
import java. awt. * ;
import java. awt. event. * ;
import javax. swing. * ;
public class java2 extends Frame______
public static void main(String args[])
java2 f=new java2("java2");
Panel pan=new Panel( );
f. init( );
public java2(String str)
super(str);
public void init( )
addWindowListener(new WindowAdapter( )
public void windowClosing(WindowEvent e)
System. exit(0);
);
setSize(200,200);
setLayout(new FlowLayout( ));
lab=new Label("Please press your keyboard!");
add(lab);
addKeyListener(this);
setVisible(true);
public void keyTyped(KeyEvent e)
lab. setText("/’"+______+"/’is pressed !");
repaint( );
public void keyPressed(KeyEvent e)
public void keyReleased(KeyEvent e)
private Label lab;
[简答题]本题程序的功能是监听键盘敲击事件,并将敲击的字符显示在标签上。开始时文字标签提示“Please press your keyboard!”,当按下键盘上的字符键时,文字标签就变为“’X’is pressed!”(X代表用户按下的键所代表的字符)。请将下述程序补充完整(注意:不得改动程序的结构,不得增行或删行)。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class simple extends Frame ______
public static void main(String args[])
simple f = new simple("simple");
Panel pan = new Panel( );
f.init( );
public simple(String str)
super (str);
public void init( )
addWindowListener(new WindowAdapter( )
public void windowClosing(WindowEvent e)
System.exit (0);
);
setSize(200,200);
setLayout(new FlowLayout( ));
lab = new Label("Please press your keyboard!");
add(lab);
addKeyListener(this);
setVisible(true);
public void keyTyped(KeyEvent e)
lab.setText("/’"+______+"/’ is pressed!");
repaint( );
public void keyPressed(KeyEvent e)
[简答题]本题的功能是监听鼠标的拖曳操作。窗口中有一个列表框,列表框中列出了当前目录的所有文件,鼠标选中一个或多个文件后拖曳出窗口,此操作的功能是将拖曳的文件复制一份在拖曳的目的目录下。
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
public class java3
{
public static void main(String[]args)
{
JFrame frame=new DragSourceFrame( );
frame.setDefauhCloseOperation(JFrame.EXIT_
0N_CLoSE);
frame.show( );
}
}
class DragSoureeFrame extends JFrame
{
public DragSourceFrame( )
{
setTitle("java3");
setSize(WlDTH,HElGHT);
Container contentPane=getContentPane( );
File f=new File(".").getabsoluteFile( );
File[]files=f.listFiles( );
model=new DefaultListModel( );
for(int i=0;i try
{
model.addElement(files[i].getCanonicalFile( ));
}
catch(IOException ex
[简答题]本题的功能是监听鼠标左右键的单击,以及面板中滚动条的添加。在窗口的画板中单击鼠标左键,在单击的位置绘制一个圆,当绘制的圆大于画板的大小时,画板就添加滚动条,在画板中单击鼠标右键,则清除画板中的所有图形。
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class java3 extends JPanel
private Dimension size;
private Vector objects;
private final Color colors[]=
Color.red,Color.blue,Color.green,Color.orange,
Color.cyan,Color.magenta,Color.darkGray,Color.yellow;
private final int color_n=colors.length;
JPanel drawingArea;
public java3( )
setOpaque(true);
size=new Dimension(0,0);
objects=new Vector( );
JLabel instructionsLeft=new JLabel("单击鼠标左键画圆.");
JLabel instructionsRight=new JLabel("单击鼠标右键清空画板.");
JPanel instructionPanel=new JPanel(new GridLayout(0,1));
instructionPanel.add(instructionsLeft);
instructionPanel.add(instructionsRight);
drawingArea=new JPanel( )
protected void paintComponen
[简答题]本题的功能是监听鼠标的操作。鼠标置于窗口中单击时(左键或右键),在单击的地方会画一个小矩形,如果将鼠标置于小矩形上,则鼠标光标状态改为小十字,按下鼠标左键可拖曳,双击鼠标左键(或右键)时,小矩形消失。
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.awt.geom.*;
import javax.swing.*;
public class java3
public static void main(String[]args)
MouseFrame frame=new MouseFrame( );
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.show( );
class MouseFrame extends JFrame
public MouseFrame( )
setTitle("java3");
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);
MousePanel panel=new MousePanel( );
Container contentPane=geeContentPane( );
contentPane.add(panel);
public static final int DEFAULT_WIDTH=300;
public static final int DEFAULT_HEIGHT=200;
class MousePanel extends JPanel
public MousePanel( )
squares=new ArrayList( );
current=null;
addMouseListener(new MouseHandler( ));
addMouseMot
[填空题]本题的功能是将文件java2. java复制为文件java2. java. bak。
import java. io. * ;
public class java2
public static void main(String sarg[])
tryFile file=new File("java2. java. bak");
______;
FileInputStream rfile=new FileInputStream("java2. java");
FileOutputStream wfile=new FileOutputStream("java2. java. bak");
int c;
while(______)
wfile. write((char)c);
rfile. close( );
wfile. close( );
catch(Exception e)System. out. println("读取文件的时候发生错误!");
System. out. println("复制操作完成!");
[简答题]本题的功能是将文件java2.java复制为文件java2.java.bak。
import java.io.*;
public class java2
public static void main(String sarg[])(
tryFile file=new File("java2.java.bak");
______;
FilelnputStream rfile=new FileInputStream("java2.java");
FileOutputStream wfile=new FileOutputStream("java2.java.bak");
int c;
while( )
wfile.write((char)c);
rfile.close( );
wfile.close( );
catch(Exception e)System.out.println("读取文件的时候发生错误!");)
System.out.println("复制操作完成!");
[简答题]本题程序的功能是通过滑动条修改颜色的RGB值,从而控制颜色。程序中有一个面板、3个标签和3个滑动条,标签和滑动条一一对应,分别对应三原色红、绿、蓝,任意拖动其中的一个滑动条,所对应的颜色值就会发生变化,面板的颜色也会对应地发生变化。滑动条值的范围是0~255。请将下述程序补充完整(注意:不得改动程序的结构,不得增行或删行)。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class simple extends JFrame implements AdjustmentListener
public simple( )
setTitle("simple");
setSize(300,200);
addWindowListener(new WindowAdapter( )
public void windowClosing(WindowEvent e)
System.exit (0);
);
Container contentPane =______;
JPanel p = new JPane1( );
p.setLayout(new GridLayout(3,2));
p.add(redLabel = new JLabel("Red 0"));
p.add(red = new JScrollBar(Adjustable.HORIZONTAL,0,0,0,255));
red.setBlockIncrement(16);
red.addAdjustmentListener(this);
p.add(greenLabel = new JLabel("Green 0"));
p.add(green = new JScrollBar(Adjustable.HORIZONTAL,0,0,0,255));
green.setBlockIncrement(16);
green.addAdjustmentListener(this);
[简答题]本题的功能是用按钮来控制文本框中文本的颜色。窗口中有两个带有文字标题的面板“Sample text”和“Text color control”,窗口的底部还有一个复选按钮“Disable changes”。在“Sample text”面板中有一个带有字符串的文本框,而在“Text color control”面板中有三个按钮“Black”、“Red”和“Green”,并且每个按钮上都有一个对应颜色的圆。单击任意按钮,文本框的文本变成对应的颜色,如果选中“Disable changes”复选框,则三个颜色按钮变为不可用,如果取消选中复选框,则三个按钮变为可用。
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class java3 extends JFrame
private JPanel upper,middle,lower;
private JTextField text;
private JButton black,red,green;
private JCheckBox disable;
public java3(String titleText)
super(titleText);
addWindowListener(new WindowAdapter( )
public void
windowClosing(WindowEvent e)
System.exit(0);
);
upper=new JPanel( );
upper.setBorder(BorderFactory.createTitledBorder("Sample text"));
Upper.setlayout(new BorderLayout( ));
text=new JTextField("Change the color of this text");
upper.add(text,BorderLayout,CENTER);
middle=new JPan
[填空题]本题的功能是用按钮来控制文字的颜色。窗口中有三个按钮“Yellow”、“Blue”和“Red”,它们分别对应文字标签中文本的颜色为黄色、蓝色和红色,单击任意一个按钮,文字标签中的文本就变成按钮对应的颜色。
import java. awt. * ;
import java. awt. event. * ;
import javax. swing. * ;
class ButtonPanel extends JPanel implements ActionListener
public ButtonPanel( )
yellowButton=new JButton("Yellow");
blueButton=new JButton("Blue");
redButton=new JButton("Red");
jl=new JLabel("I am from China!");
add(yellowButton);
add(blueButton);
add(redButton);
add(jl);
yellowButton. addActionListener(this);
blueButton. addActionListener(this);
redButton. addActionListener(this);
public void actionPerformed(ActionEvent evt)
Object source=evt. getSource( );
Color color=getForeground( );
if(source==yellowButton) color=Color. yellow;
else if(source==blueButton) color=Color. blue;
else if(source==redButton) color=Color. red;
______;
______;
private JButton yellowButton;
[简答题]本题的功能是定义自已的组件类。窗口中排布着12个按钮,鼠标移动按钮时,按钮背景颜色改变,用鼠标单击按钮时,后台将显示该按钮对应的字符。
import java.awt.*;
import java.awt.event.*;
import java.util.*;
class java3 extends Frame{
String keys="l23456789*0#";
java3( ){
super("java3");
addWindowListener(new WindowAdapter( ){
public void windowClosing(WindowEvent e){
System.exit(O);
}
});
setLayout(new GridLayout(4,3,6,6));
for(int i=0;i KeyButton kb=new KeyButton(keys.charAt
(i));
kb.addkeyListener(this);
kb.setBackground(Color.pink);
kb.setForeground(Color.black);
add(kb);
}
setSize(200,200);
show( );
}
class KeyEventHandler extends KeyAdapter{
public void keyTyPed(KeyEvent evt){
System.out.println(evt.getChar( ));
}
}
public static void main(String[]args){
newjava3( );
}
}
class KeyButton extends Component{