如何将鼠标悬停侦听器添加到Java中的矩形

I am trying to make a button using the Rectangle object and am also trying to make the color change on hover, and it will not change. I have made my code have more generic names for variables that way it would not confuse, here it is:

我正在尝试使用Rectangle对象创建一个按钮,并且还尝试在悬停时进行颜色更改,并且它不会更改。我已经使我的代码有更多的通用名称变量,它不会混淆,这里是:

public class MouseHandler extends MouseAdapter {
    @Override
    public void mouseMoved(MouseEvent e) {
        int mx = e.getX();
        int my = e.getY();
        if(mx > button.x && mx < button.x+button.width &&
                my > button.y && my < button.y+button.height) {
                buttonHover = true;
        } else {
                buttonHover = false;

        }
    }
}

And I tried calling these lines of code also, but it wouldn't work:

我也试过调用这些代码行,但它不起作用:

if(buttonHover)
g.setColor(hoverColor);
g.drawRect(button.x, button.y, button.width, button.height);

I will put my full code at the bottom, with the actual variable names. Thanks for the help!

我将把我的完整代码放在底部,带有实际的变量名。谢谢您的帮助!

package trivia;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class Main extends JFrame{

boolean mainMenu = true;
boolean startHover;
static Color tan = Color.decode("#F4EBC3");
static Color darkGreen = Color.decode("#668284");
static Color buttonColor = Color.decode("#A2896B");
static Color borderColor = Color.decode("#333333");
static Color buttonHover = Color.decode("#F5B66E");
Rectangle header = new Rectangle(0, 0, 500, 100);
Rectangle body = new Rectangle(0, 100, 500, 400);
Rectangle start = new Rectangle(150, 150, 200, 40);
Rectangle howToPlay = new Rectangle(150, 225, 200, 40);
Rectangle quit = new Rectangle(150, 300, 200, 40);

public Main() {
    setTitle("Trivia Game!");
    setSize(500, 500);
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);

}
@Override
public void paint(Graphics g) {
    Dimension d = this.getSize();
    if(mainMenu = true){
        g.setColor(darkGreen);
        g.fillRect(header.x, header.y, header.width, header.height);
        g.setFont(new Font("Courier", Font.BOLD, 24));
        g.setColor(Color.BLACK);
        drawCenteredString("Trivia Game!", d.width, 125, g);
        g.setColor(tan);
        g.fillRect(body.x, body.y, body.width, body.height);
        g.setColor(buttonColor);
        g.fillRect(start.x, start.y, start.width, start.height);
        g.setColor(borderColor);
        g.drawRect(start.x, start.y, start.width, start.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Start", d.width, 340, g);
        g.setColor(buttonColor);
        g.fillRect(howToPlay.x, howToPlay.y, howToPlay.width, howToPlay.height);
        g.setColor(borderColor);
        g.drawRect(howToPlay.x, howToPlay.y, howToPlay.width, howToPlay.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("How To Play", d.width, 490, g);
        g.setColor(buttonColor);
        g.fillRect(quit.x, quit.y, quit.width, quit.height);
        g.setColor(borderColor);
        g.drawRect(quit.x, quit.y, quit.width, quit.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Quit?", d.width, 640, g);
        g.setColor(buttonColor);
        g.fillRect(start.x, start.y, start.width, start.height);
        g.setColor(borderColor);
        g.drawRect(start.x, start.y, start.width, start.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Start", d.width, 340, g);
        if(startHover)
            g.setColor(buttonHover);
            g.drawRect(start.x, start.y, start.width, start.height);
    }
}
public void drawCenteredString(String s, int w, int h, Graphics g) {
    FontMetrics fm = g.getFontMetrics();
    int x = (w - fm.stringWidth(s)) / 2;
    int y = (fm.getAscent() + (h- (fm.getAscent() + fm.getDescent())) / 2);
    g.drawString(s, x, y);
}

public static void main(String[] args) {
    @SuppressWarnings("unused")
    Main m = new Main();
}
public class MouseHandler extends MouseAdapter {
    @Override
    public void mouseMoved(MouseEvent e) {
        int mx = e.getX();
        int my = e.getY();
        if(mx > start.x && mx < start.x+start.width &&
                my > start.y && my < start.y+start.height) {
                startHover = true;
                System.out.println("yes");
        } else {
                startHover = false;
                System.out.println("no");
        }
    }
}
}

2 个解决方案

#1

I'll start with...

我会从...开始

1) If it truly just a rectangle you want to deal with. Please use https://docs.oracle.com/javase/7/docs/api/java/awt/Rectangle.html , Java has been kind enough to make your life simple please don't throw it away. (ignore this keeping here for reference)

1)如果它真的只是一个你想要处理的矩形。请使用https://docs.oracle.com/javase/7/docs/api/java/awt/Rectangle.html,Java已经足够让您的生活变得简单,请不要丢弃它。 (忽略这个保留在这里供参考)

2) You should implement MouseMotionListener... I did it for you.

2)你应该实现MouseMotionListener ...我为你做了。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;

@SuppressWarnings("serial")
public class test extends JFrame  implements MouseMotionListener {

boolean mainMenu = true;
boolean startHover;
static Color tan = Color.decode("#F4EBC3");
static Color darkGreen = Color.decode("#668284");
static Color buttonColor = Color.decode("#A2896B");
static Color borderColor = Color.decode("#333333");
static Color buttonHover = Color.decode("#F5B66E");
Rectangle header = new Rectangle(0, 0, 500, 100);
Rectangle body = new Rectangle(0, 100, 500, 400);
Rectangle start = new Rectangle(150, 150, 200, 40);
Rectangle howToPlay = new Rectangle(150, 225, 200, 40);
Rectangle quit = new Rectangle(150, 300, 200, 40);

public test() {
    setTitle("Trivia Game!");
    setSize(500, 500);
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);
    this.addMouseMotionListener(this);
}

@Override
public void paint(Graphics g) {
    Dimension d = this.getSize();
    if (mainMenu = true) {
        g.setColor(darkGreen);
        g.fillRect(header.x, header.y, header.width, header.height);
        g.setFont(new Font("Courier", Font.BOLD, 24));
        g.setColor(Color.BLACK);
        drawCenteredString("Trivia Game!", d.width, 125, g);
        g.setColor(tan);
        g.fillRect(body.x, body.y, body.width, body.height);
        g.setColor(buttonColor);
        g.fillRect(start.x, start.y, start.width, start.height);
        g.setColor(borderColor);
        g.drawRect(start.x, start.y, start.width, start.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Start", d.width, 340, g);
        g.setColor(buttonColor);
        g.fillRect(howToPlay.x, howToPlay.y, howToPlay.width,
                howToPlay.height);
        g.setColor(borderColor);
        g.drawRect(howToPlay.x, howToPlay.y, howToPlay.width,
                howToPlay.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("How To Play", d.width, 490, g);
        g.setColor(buttonColor);
        g.fillRect(quit.x, quit.y, quit.width, quit.height);
        g.setColor(borderColor);
        g.drawRect(quit.x, quit.y, quit.width, quit.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Quit?", d.width, 640, g);
        g.setColor(buttonColor);
        g.fillRect(start.x, start.y, start.width, start.height);
        g.setColor(borderColor);
        g.drawRect(start.x, start.y, start.width, start.height);
        g.setFont(new Font("Courier", Font.BOLD, 20));
        g.setColor(Color.black);
        drawCenteredString("Start", d.width, 340, g);
        if (startHover)
            g.setColor(buttonHover);
        g.drawRect(start.x, start.y, start.width, start.height);
    }
}

public void drawCenteredString(String s, int w, int h, Graphics g) {
    FontMetrics fm = g.getFontMetrics();
    int x = (w - fm.stringWidth(s)) / 2;
    int y = (fm.getAscent() + (h - (fm.getAscent() + fm.getDescent())) / 2);
    g.drawString(s, x, y);
}

public static void main(String[] args) {
    @SuppressWarnings("unused")
    test m = new test();
}

@Override
public void mouseDragged(MouseEvent arg0) {
    // TODO Auto-generated method stub

}

@Override
public void mouseMoved(MouseEvent e) {
    System.out.println("lol");
    int mx = e.getX();
    int my = e.getY();
    if (mx > start.x && mx < start.x + start.width && my > start.y
            && my < start.y + start.height) {
        startHover = true;
        System.out.println("yes");
    } else {
        startHover = false;
        System.out.println("no");
    }
}
}

If you read below you can see there are a lot of things wrong with your code. Don't let that scare you from learning. Do it step by step and you will be fine.

如果你在下面看到,你会发现你的代码有很多问题。不要让那吓到你学习。一步一步做,你会没事的。

#2

You've several issues going on here:

你有几个问题在这里发生:

• You're doing drawing directly within a JFrame, a dangerous thing to do, since JFrames hold many components, several I'm sure that you're not familiar with, including borders, rootpane, glasspane, and contentpane, and if you mess up painting, it can mess up the drawing of these critical components.

你正在JFrame中直接绘图,这是一个危险的事情,因为JFrames拥有许多组件,有几个我确定你不熟悉,包括边框,rootpane,glasspane和contentpane,如果你搞砸了绘画,它可以弄乱这些关键组件的绘制。

• Also by painting inside of a paint method, you loose all the advantages of Swing graphics.

此外,通过在绘制方法内部绘画,您将失去Swing图形的所有优点。

• Also you appear to have most of your program design and logic within a painting method, something that you should never do since you don't have full control over when or even if that method gets called.

此外,您似乎在绘画方法中拥有大部分程序设计和逻辑,这是您永远不应该做的事情,因为您无法完全控制何时或甚至调用该方法。

• Instead, you should create your button component in its own class, separate from the JFrame

相反,您应该在自己的类中创建按钮组件,与JFrame分开

• Give your class ability to be placed in a JPanel

将您的课程能力放在JPanel中

• And give it a rollover capability.

并赋予它翻转功能。

• For my money though, I'd just extend a JButton or better, just use a JButton, and make it look the way I want rather than trying to re-invent the wheel.

但是对于我的钱,我只是扩展一个JButton或更好,只需使用一个JButton,让它看起来像我想要的方式,而不是试图重新发明*。

---

e.g.,

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridBagLayout;
import java.awt.GridLayout;

import javax.swing.*;
import javax.swing.border.Border;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

@SuppressWarnings("serial")
public class Main2 extends JPanel {
   private static final Color TAN = Color.decode("#F4EBC3");
   private static final Color DARK_GREEN = Color.decode("#668284");
   private static final Color BUTTON_COLOR = Color.decode("#A2896B");
   private static final Color BORDER_COLOR = Color.decode("#333333");
   private static final Color BUTTON_ROLLOVER_COLOR = Color.decode("#F5B66E");
   private static final String TITLE = "Trivia Game!";
   private static final Font TITLE_FONT = new Font("Courier", Font.BOLD, 24);
   private static final int PREF_W = 500;
   private static final int PREF_H = PREF_W - 30;
   private JButton startButton;
   private JButton howToPlayButton;
   private JButton quitButton;


   public Main2() {
      JLabel titleLabel = new JLabel(TITLE, SwingConstants.CENTER);
      titleLabel.setFont(TITLE_FONT);
      int blGap = 15;
      titleLabel.setBorder(BorderFactory.createEmptyBorder(blGap, blGap, blGap, blGap));
      JPanel titlePanel = new JPanel(new GridBagLayout());
      titlePanel.setBackground(DARK_GREEN);
      titlePanel.add(titleLabel);

      JPanel centerInnerPanel = new JPanel(new GridLayout(0, 1, blGap, 2 * blGap));
      centerInnerPanel.setOpaque(false);
      centerInnerPanel.setBorder(BorderFactory.createEmptyBorder(blGap, blGap, blGap, blGap));
      centerInnerPanel.add(startButton = createButton("Start"));
      centerInnerPanel.add(howToPlayButton = createButton("How To Play"));
      centerInnerPanel.add(quitButton = createButton("Quit?"));

      JPanel centerOuterPanel = new JPanel(new GridBagLayout());
      centerOuterPanel.setBackground(TAN);
      centerOuterPanel.add(centerInnerPanel);


      setLayout(new BorderLayout());
      add(titlePanel, BorderLayout.PAGE_START);
      add(centerOuterPanel, BorderLayout.CENTER);
   }

   private JButton createButton(String name) {
      final JButton button = new JButton(name);
      button.setFont(TITLE_FONT.deriveFont(20F));
      button.setBackground(BUTTON_COLOR);
      Border emptyBorder = BorderFactory.createEmptyBorder(5, 25, 5, 25);
      Border lineBorder = BorderFactory.createLineBorder(BORDER_COLOR);
      Border nestedBorder = BorderFactory.createCompoundBorder(lineBorder, emptyBorder);
      button.setBorder(nestedBorder);


      button.getModel().addChangeListener(new ChangeListener() {

         @Override
         public void stateChanged(ChangeEvent e) {
            ButtonModel model = (ButtonModel)e.getSource();
            if (model.isRollover()) {
               button.setBackground(BUTTON_ROLLOVER_COLOR);
            } else {
               button.setBackground(BUTTON_COLOR);
            }
         }
      });

      return button;
   }

   @Override
   public Dimension getPreferredSize() {
      if (isPreferredSizeSet()) {
         return super.getPreferredSize();
      }
      int w = Math.max(super.getPreferredSize().width, PREF_W);
      int h = Math.max(super.getPreferredSize().height, PREF_H);

      return new Dimension(w, h);
   }

   private static void createAndShowGui() {
      Main2 mainPanel = new Main2();

      JFrame frame = new JFrame("Main2");
      frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}