刚接触java,涉及到关于Applet对象的键盘监听和响应程序中有一语句Alpha rotationAlpha=new Alpha(-1,Alpha.INCREASING_ENABLE,0,0,s,0,0,0,0,0);
其中有一变量s,我需要通过键盘按键来改变s值,以控制某些变化。
按VK_UP键使s=s-100
按VK_DOWN键s=s+100我写的程序不起作用,请问应该怎么写?
其中有一变量s,我需要通过键盘按键来改变s值,以控制某些变化。
按VK_UP键使s=s-100
按VK_DOWN键s=s+100我写的程序不起作用,请问应该怎么写?
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;import javax.swing.JApplet;
import javax.swing.JPanel;public class JAppletTest2 extends JApplet {
int s; /**
* Create the applet
*/
public JAppletTest2() {
super();
final JPanel panel = new JPanel();
panel.setBounds(0, 0, 220, 120);
getContentPane().add(panel); s = 0;
addKeyListener(new KeyAdapter() {
public void keyPressed(final KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_PAGE_DOWN:
s += 100;
repaint();
break;
case KeyEvent.VK_PAGE_UP:
s -= 100;
repaint();
break;
default:
break;
}
}
}); getContentPane().setLayout(null); //
} public void paint(Graphics g) {
g.clearRect(g.getClipRect().x, g.getClipRect().y,
g.getClipRect().width, g.getClipRect().height);
g.drawString(new Integer(s).toString(), 10, 10);
}}
import java.applet.Applet;
import java.awt.Button;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.*; public class Test extends Applet
{
public int s; public Test()
{
s=500;
Button b = new Button();
this.add(b);
this.setLayout(null);
b.setBounds(0, 0, 0, 0);
b.requestFocus();
b.addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_UP)
{
s -= 100;
}
else if (e.getKeyCode() == KeyEvent.VK_DOWN)
{
s += 100;
}
repaint();
}
}
);
} public void paint(Graphics g)
{
g.drawString("s="+s, 80, 100);
}
}
import java.applet.Applet;
import java.awt.Button;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.*; public class Test extends Applet
{
public int s; public Test()
{
s=500;
Button b = new Button();
this.add(b);
this.setLayout(null);
b.setBounds(0, 0, 0, 0);
b.requestFocus();
b.addKeyListener(new KeyAdapter()
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_UP)
{
s -= 100;
}
else if (e.getKeyCode() == KeyEvent.VK_DOWN)
{
s += 100;
}
repaint();
}
}
);
} public void paint(Graphics g)
{
g.drawString("s="+s, 80, 100);
}
}
import java.awt.*;
import java.applet.Applet;
import java.awt.Graphics;
import java.awt.event.*;
public class Test extends Applet implements KeyListener
{
Label lab1;
int s;
public void init()
{
s=100;
//下面几个代码很关键
setLayout(null);//没有这个的话,貌似就会显示一个按钮出来
Button b=new Button();
b.setBounds(0, 0, 0, 0);//设置按钮的位置和大小
add(b);
b.addKeyListener(this);//这个贼关键啦!
b.requestFocus();//前面的b.也可以不要
}
public void keyPressed(KeyEvent e)//必须要有这个函数
{
//
if(e.getKeyCode()==(KeyEvent.VK_DOWN))
{
s=s-100;
}
if(e.getKeyCode()==(KeyEvent.VK_UP))
{
s=s+100;
}
// repaint();
}
public void keyReleased(KeyEvent e)//必须要有这个函数
{
//还可以把上面////之间的代码放在这里
repaint();
}
public void keyTyped(KeyEvent e)//必须要有这个函数
{
repaint();
}
public void paint(Graphics g)
{
g.drawString("s="+s, 80, 100);
}
}