下列Applet实现了使用灰度值递减的顺序显示0~9,选择正确的语句填入横线处。 import java.applet.*; import java.awt.*; import java.awt.Color; public class ex24 extends Applet { public void paint(Graphics g) { int r = 0, g1 = 0, b = 0, j = 10; for(int i - 0; i < 10; i ++) { g.setColor(new Color(r, g1, b)); r += 25; g1 +=25; b +=25; j += 10; } } }
A.g.drawString(i, j, 30);
B.g.drawString("" + i, j, 30);
C.drawString(i,j, 30);
D.drawstring("" + i,j, 30);
第1题:
下列Applet实现了在Applet窗口中绘制一个以(70,70)为圆心,50为半径,边框为绿色的圆,圆心是红色的。选择正确的语句填入下面横线处。 import java.awt.*; import java.applet.*; public class ex20 extends Applet { public void paint(Graphics g) { g.setColor(Color. GREEN); g.drawOval(20, 20, 100, 100); g.setColor(Color. RED); ______ } }
A.g.drawOval(70, 70, 70, 70);
B.g.drawRect(70, 70, 1, 1);
C.drawRect(70, 70, 1, 1);
D.g.drawLine(70, 70, 1, 1);
第2题:
下列Applet在坐标(30,50)处以黄色字体显示“你好!”。请选择正确的语句填入横线处。 import java.awt.*; import java.applet.*; public class ex27 extends Applet { public void paint<Graphics g) { g.drawString("你好", 30, 50); } }
A.setColor(Color.yellow);
B.g.setColor(Color. Yellow),
C.g.setFontColor(Color. yellow);
D.g.setColor(Color. yellow);
第3题:
在编写Applet程序时,程序中必须有的import语句是
A.import.java.io.*;
B.import java.applet.Applet;
C.import.java.awt.event.*;
D.import.java.lang.*;
第4题:
下列Applet实现画一条连接窗口右上角的直线。选择正确的语句填入横线处。 import java.applet.*; import java.awt.*; public class ex25 extends Applet { public void paint (Graphics g) { Dimension d; d = getSize(); ______ } } ______ } }
A.g.drawLine(d.width, al.height, 0, 0);
B.g.drawLine(0, d.height, d.width, 0);
C.g.drawLine(0, 0, d. width, 0);
D.g.drawLine(0, d.height, 0, d.width);
第5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);