这是创建一个Frame并保存实现Graphics的类的MainApplication。Keylistener可以工作,但并未执行预期的操作。为什么?
MainApplication.java
import java.awt.*;
public class MainApplication
{
public MainApplication()
{
Frame frame= new Frame("Test App");
frame.add(new KeyTest());
frame.setBackground(Color.RED);
frame.setLayout(null);
frame.setSize(700,750);
frame.setVisible(true);
}
public static void main(String args[])
{
new MainApplication();
}
}
此类创建所有的图形形状,也实现了KeyListener的。
KeyTest.java
import java.awt.BasicStroke;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.RoundRectangle2D;
public class KeyTest extends Canvas {
/**
*
*/
private static final long serialVersionUID = 3L;
Graphics2D graphics2D;
Color color = Color.BLACK;
private static float borderThickness = 5;
Shape firstShape = new RoundRectangle2D.Double(20,40,300,50,10,10);
Shape secondShape = new RoundRectangle2D.Double(20,150,300,50,10,10);
public KeyTest()
{
setBackground(Color.RED);
setSize(700,750);
}
public void paint(Graphics graphics)
{
graphics2D = (Graphics2D)graphics; //TypeCasting to 2D
System.out.println("I am inside paint");
// Smoothening the corners
graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Apple border color
Stroke oldStroke = graphics2D.getStroke();
graphics2D.setStroke(new BasicStroke(borderThickness));
graphics2D.setColor(Color.WHITE);
// Drawing a RoundedRectangle for Apple
graphics2D.draw(firstShape);
graphics2D.setStroke(oldStroke);
// Setting the Background Color
graphics2D.setColor(Color.BLACK);
graphics2D.fill(firstShape);
// Setting the font inside the shape
Font firstFont = new Font("Serif", Font.BOLD,35);
graphics2D.setFont(firstFont);
graphics2D.setColor(Color.WHITE);
graphics2D.drawString("Apple",30,80);
// Pineapple border color
graphics2D.setStroke(new BasicStroke(borderThickness));
graphics2D.setColor(Color.WHITE);
// Drawing a RoundedRectangle for Pineapple
graphics2D.draw(secondShape);
graphics2D.setStroke(oldStroke);
// Setting the Background Color
graphics2D.setColor(Color.BLACK);
graphics2D.fill(secondShape);
// Setting the font inside the shape
Font secondFont = new Font("Serif", Font.BOLD,35);
graphics2D.setFont(secondFont);
graphics2D.setColor(Color.WHITE);
graphics2D.drawString("Pineapple",30,190);
addKeyListener(new KeyListener(){
@Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
@Override
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
System.out.println(keyCode);
System.out.println(KeyEvent.VK_UP);
if(keyCode==KeyEvent.VK_UP){
System.out.println("Going to move up");
move(firstShape);
}
if(keyCode==KeyEvent.VK_DOWN){
System.out.println("Going to move down");
move(secondShape);
}
}
@Override
public void keyReleased(KeyEvent e) {
// TODO Auto-generated method stub
}});
}
public void move(Shape s){
System.out.println("Check:"+s.getBounds2D());
graphics2D.setColor(Color.GREEN);
graphics2D.fill(s);
System.out.println("moving out");
}
}
我的控制台输出清楚地表明,我的主要作品监听器,但其不执行,我想让它做任务。
控制台输出
我里面的油漆要拉升
检查:java.awt.geom.Rectangle2D中$双[X = 20.0,Y = 40.0,W = 300.0,H = 50.0]
移出要向下移动
检查:java.awt.geom.Rectangle2D中$双[X = 20.0,Y = 150.0,W = 300。 0,H = 50.0]
移出
OUTPUT:
现在正在逐渐输出..(IMAGE 1)
我期望当我按下向下箭头按钮的输出(图像2)
我期望当我按下上箭头按钮的输出(图像3)
可能你必须在你的框架上触发某种重绘/刷新。提示:在你的问题中包含所有**图像绝对没有意义。 – GhostCat
在'paint'方法内部添加'KeyListener'根本看起来不太好。 – Berger
将它添加到外面并没有达到目的,这就是为什么我将它添加到“paint”方法内的原因。 –