问答题 本题的功能是通过鼠标确定两个点,然后画两点间的直线。窗口中有一个按钮“Draw line”,单击该按钮后,它就处于按下状态,然后用鼠标在窗口中单击一下,在单击的地方就会出现一个坐标圆点,用鼠标在另外一个地方单击一下又会出现另外一个圆点,并且此时在两个坐标圆点间画出一条直线,且“Draw line”处于可用状态,再单击这个按钮就可以画另外一条直线。 Import java.awt.* ; import java.awt.event.*; import javax.swing.*; class EventQueuePanel extends JPanel implements Ac- tionListener {EventQueuePanel() {JButton button=new JButton("Draw line"); add(button); button.addActionListener(this); } public void actionPerformed(ActionEvent evt) (Graphics g=getGraphics(); P=getClick(); g.drawOval(P.x-2,P.Y-2,4,4); Point q=getClick(); g.drawOval(q.x-2,q.y-2,4,4); g.drawLine(P.X,P.Y,q.x,q.y); g.dispose(); } public Point getClick() {EventQueue eq=Toolkit.getDefaultToolkit(). getSystemEventQueue(); while(true) {try {AWTEvent evt=eq.getNextEvent(); if(evt.getID()= =MouseEvent.MOUSE. PRESSED) {MouseEvent mevt=(MouseEvent)evt; Point P= (); Point top=getRootPane().getLocation(); P.X-=top.x; P.Y-=top.Y; return P; } } catch(InterruptedException e) {} } } private int Y=60; } class EventQueueFrame extends JFrame {public EventQueueFrame() {setTitle("java2"); setSize(300,200); addWindowListener(new WindowAdapter() {public void windowClosing(WindowEvent e) {System.exit(0); } }); Container contentPane=getContentPane(); contentPane.add(new EventQueuePanel()); } } public class java2 {public static void main(String[]args) {Frame frame=new EventQueueFrame(); frame.show(); } }
判断题 合作游戏是指由教师建议或开始一个游戏,教师事先定好某些角色,以部分控制游戏的进行。()
问答题 本题中定义了一个树型的通信录,窗El左侧是一个树, 右侧是一个文本域,单击树的结点,则在右侧文本域中显示 相关信息,如果单击的是树结点,则显示对应名字的电话 信息。 import javax.swing.*; import javax.swing.tree.*; import java.awt.*; import java.awt.event.*; import javax.swing.event.*; class Mytree2 extends JFrame {JTree tree=null;JTextArea text=new JTextArea (20,20); Mytree2() {Container con=getContentPane(); DefauhMutableTreeNode root=new Default- MutableTreeNode("同学通信录"); DefaultMutableTreeNode tl=new Default- MutableTreeNode("大学同学"); DefaultMutableTreeNode t2=new Default- MutableTreeNode("研究生同学"); DefaultMutableTreeNode tl l=new Default- MutatleTreeNode("陈艳"); DefaultMutableTreeNode tl 2=new Default- MutableTreeNode("李小永"); DefaultMutableTreeNode t2 1=new Defauh- MutableTreeNode("王小小"); DefauhMutableTreeNode t2 2=new Defauh- MutableTreeNode("董小"); setTitle("java2"); root.add(t1);root.add(t2); tl.add(t1_1);tl.add(t1_2);t2.add(t2_1);t2. add(t2_2); tree=new JTree(root); JSerollPane scrollpane=new JScrollPane(text); JSplitPane splitpane=new JSplitPane(JSplitPane. HORIZONTAL SPLIT, true,tree,scrollpane); tree.addTreeSeleetionListener(this); con.add(splitpane); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) {System.exit(0);}}); setVisible(true);setBounds(70,80,200,300); } public void valueChanged(TreeSelectionEvent e) {if(e.getSouree()= =tree) {DefauhMutableTreeNode node= (DefaultMutableTreeNode)tree.getLastSelected- PathComponent(); if(node.isLeaf()) (String str= ; if(str.equals("陈艳")) (text.setText(str+":联系电话:0411- 4209876");} else if(str.equals("李小永")) {text.setText(str+":联系电话:010- 62789876");} else if(str.equals("王小小")) {text.setText(str+":联系电话:0430- 63596677");) else if(str.equals("董小")) {text.setText(str+":联系电话:020- 85192789");} } else {text.setText(node.getUserObject().toString ()); } } } } public class java2 {public static void main(String args[]) {Mytree2 win=new Mytree2();win.pack();} }