当我在鼠标的x和y坐标上按下鼠标时,我创建它来画一条鱼。但我似乎没有调用drawfish方法。我找不到它无法正常工作的原因。我会非常感谢任何帮助。
/*FishTank*/
import java.awt.Graphics;
import javax.swing.JComponent;
import javax.swing.JFrame;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
/*FishTank class-contains a frame and the WinstonCanvas.*/
public class FishTank{
public static void main ( String[] args ){
javax.swing.SwingUtilities.invokeLater(new Runnable(){
public void run(){
JFrame window = new JFrame();
window.setTitle("Fish Tank");
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 700, 430);
window.getContentPane().add(new FishTankCanvas());
window.setVisible(true);
}
});
}
}
/*FishTankCanvas is a component that allows drawing shapes.*/
class FishTankCanvas extends JComponent {
static Graphics2D g;
int x = 11;
Timer myTimer;
public FishTankCanvas(){
myTimer = new Timer (2, new ActionListener(){
public void actionPerformed (ActionEvent evt){
repaint();
}
});
myTimer.start();
}
public void paint(Graphics graphics) {
g = (Graphics2D)graphics;
//makes the background white
Color backgroundColor = new Color(89, 216, 255);//light blue
g.setColor(backgroundColor);
g.fillRect(0,0,this.getWidth(),this.getHeight());
// drawfish (Graphics graphics, int bodyX, int bodyY, int bodyLength,int bodyHeight, int tailwidth, int eyesize,int tailcolor, int bodycolor)
// Mouselistener and mouseadapter
this.addMouseListener (new MouseAdapter() {
public void mousePressed(MouseEvent e) {
//call drawfish method
drawfish(FishTankCanvas.g,e.getX(), e.getY(),118,74,1,((int) (Math.random()*(4 - 0))));
repaint();
}
});
// x coordinate plus 1 of fish (animate)
x= x + 1;
}
// drawfish method
public void drawfish(Graphics graphics, int bodyX, int bodyY, int bodyLength,int bodyHeight,int tailcolor, int bodycolor ){
Graphics2D g = (Graphics2D)graphics;
bodyX +=x;
//colours
Color[] colours= new Color[5];
colours[0] = new Color(0, 0, 0);//black
colours[1] = new Color(162, 0, 255);//purple
colours[2] = Color.red;//red
colours[3] = new Color(255,255,0);// yellow
colours[4] = new Color(60,179,113);//green
//draw fish
// body
g.setColor(colours[bodycolor]);
g.fillOval(bodyX, bodyY, bodyLength, bodyHeight);
// tail
g.setColor(colours[tailcolor]);
int tailWidth = bodyLength/4;
int tailHeight = bodyHeight/2;
int[] tailPointx = new int[3];
int[] tailPointy = new int[3];
tailPointx[0]=bodyX;
tailPointy[0]=bodyY+bodyHeight/2;
tailPointx[1]=bodyX-tailWidth;
tailPointy[1]=bodyY+bodyHeight/2-tailHeight;
tailPointx[2]=bodyX-tailWidth;
tailPointy[2]=bodyY+tailHeight+tailHeight;
g.fillPolygon(tailPointx, tailPointy, 3);
// eye
g.setColor(colours[0]);
g.fillOval(bodyX+3*bodyLength/4, bodyY+bodyHeight/2-bodyHeight/5, bodyHeight/5, bodyHeight/5);
}
}
答案 0 :(得分:3)
我似乎没有调用drawfish方法。
这很容易验证。您需要做的就是向方法添加调试代码以确定是否为真。然后你可以告诉我们这是问题而不是猜测。
其他问题:
不要在绘图方法中将MouseListener添加到组件中。应该在你的类的构造函数中添加监听器。
不要覆盖paint()。通过覆盖paintComponent()
方法完成自定义绘制。并且不要忘记调用super.paintComponent(...)。
扩展JPanel而不是JComponent。然后你可以使用setBackground()方法绘制背景。
然而,真正的问题是,当你点击鼠标时,鱼可能会被绘制,但是然后Timer会重新绘制,这将在2ms之后清除面板,所以你永远不会真正看到鱼。摆脱计时器。定时器不需要画鱼。
假设你要画多条鱼,你需要跟踪你点击的每个地方,然后画掉所有的鱼。这样做的两种方式是:
有关这两种方法的工作示例,请参阅Custom Painting Approaches。