Question

我试图将按键侦听器分配给在for循环中创建的按钮。由于某种原因，我无法获得用于更改按键背景颜色的按钮。 from sklearn.ensemble import RandomForestRegressor from sklearn.datasets import make_regression X, y = make_regression(n_features=4, n_informative=2, random_state=0, shuffle=False) regr = RandomForestRegressor(max_depth=2, random_state=0) regr.fit(X, y) regr.predict([[0, 0, 0, 0]])行已到达，因此我不确定发生了什么。

很多意大利面条代码..请让我知道我还应该添加什么。

System.out.println("passed");

编辑1：

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;

public class ButtonInPane extends JFrame implements KeyListener {
 // input
 String input;
 //context
 JLabel context1, context2;
 // default color
 Color defaultColor = new JButton().getBackground();
 public void addNotify() {
  super.addNotify();
  requestFocus();
 }
 // main rows of keys
 public String rowOne[] = {
  "~",
  "1",
  "2",
  "3",
  "4",
  "5",
  "6",
  "7",
  "8",
  "9",
  "0",
  "-",
  "+",
  "h"
 };
 public String rowTwo[] = {
  "Tab",
  "Q",
  "W",
  "E",
  "R",
  "T",
  "Y",
  "U",
  "I",
  "O",
  "P",
  "[",
  "]",
  "\\"
 };
 public String rowThree[] = {
  "Caps",
  "A",
  "S",
  "D",
  "F",
  "G",
  "H",
  "J",
  "K",
  "L",
  ":",
  "'",
  "Enter"
 };
 public String rowFour[] = {
  "Shift",
  "Z",
  "X",
  "C",
  "V",
  "B",
  "N",
  "M",
  ",",
  ".",
  "?",
  "   ^"
 };
 public String rowFive[] = {
  "       ",
  "<",
  "v",
  ">"
 };
 /**
  * Account for chars with no shift: Program toggles Shift key, meaning if a
  * user clicks on it, all keys will be toggled to their respective shift
  * value. The user can tap the shift key again to change back to regular
  * value
  */
 public String shiftless[] = {
  "1",
  "2",
  "3",
  "4",
  "5",
  "6",
  "7",
  "8",
  "9",
  "0",
  "-",
  "=",
  "q",
  "w",
  "e",
  "r",
  "t",
  "y",
  "u",
  "i",
  "o",
  "p",
  "[",
  "]",
  "\\",
  "a",
  "s",
  "d",
  "f",
  "g",
  "h",
  "j",
  "k",
  "l",
  ";",
  "z",
  "x",
  "c",
  "v",
  "b",
  "n",
  "m",
  ",",
  ".",
  "/"
 };
 // Account for special chars
 public String specialChars[] = {
  "~",
  "-",
  "+",
  "[",
  "]",
  "\\",
  ";",
  ".",
  "?"
 };

 // declare rows of buttons
 public JButton buttons_rowOne[], buttons_rowTwo[], buttons_rowThree[], buttons_rowFour[], buttons_rowFive[];
 private JTextArea body;
 private JPanel top;
 private JPanel middle;
 private JPanel bottom;
 private JPanel contextBox;

 // ctor
 public ButtonInPane() {
  super("Typing Tutor");
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  this.setResizable(false);
  this.getContentPane().setPreferredSize(new Dimension(1000, 600));
  this.setLocation(50, 50);
  this.setVisible(true);
  __init__();
 }

 public void __init__layout(JPanel top, JPanel middle, JPanel bottom, JPanel contextBox) {
  setLayout(new BorderLayout());
  add(top, BorderLayout.NORTH);
  add(contextBox);
  add(middle, BorderLayout.CENTER);
  add(bottom, BorderLayout.SOUTH);
 }

 public void __init__body() {
  body = new JTextArea();
  body.setPreferredSize(new Dimension(1000, 150));
  body.addKeyListener(this);
 }

 public void __init__panels() {
  context1 = new JLabel("Type some text using your keyboard. " +
   "The keys you press will be highlighed and the text will be displayed.");
  context2 = new JLabel("\nNote: Clicking the buttons with your mouse will not perform any action.");
  context1.setFont(new Font("Verdana", Font.BOLD, 14));
  context2.setFont(new Font("Verdana", Font.BOLD, 14));
  top = new JPanel();
  top.setSize(new Dimension(500, 500));
  middle = new JPanel();
  bottom = new JPanel();
  contextBox = new JPanel();
  __init__layout(top, middle, bottom, contextBox);
  top.setLayout(new BorderLayout());
  bottom.setLayout(new GridLayout(5, 5));
  top.add(context1);
  top.add(context2);
  middle.setLayout(new BorderLayout());
  middle.add(body, BorderLayout.WEST);
  middle.add(body, BorderLayout.CENTER);
 }

 public void __init__() {
  // text area
  __init__body();
  // panels for layout
  __init__panels();
  pack();
  // get length of row strings
  int length_rowOne = rowOne.length;
  int length_rowTwo = rowTwo.length;
  int length_rowThree = rowThree.length;
  int length_rowFour = rowFour.length;
  int length_rowFive = rowFive.length;
  // create array for each row of buttons
  buttons_rowOne = new JButton[length_rowOne];
  buttons_rowTwo = new JButton[length_rowTwo];
  buttons_rowThree = new JButton[length_rowThree];
  buttons_rowFour = new JButton[length_rowFour];
  buttons_rowFive = new JButton[length_rowFive];
  // create panel for each row of buttons
  JPanel r1 = new JPanel(new GridLayout(1, length_rowOne));
  JPanel r2 = new JPanel(new GridLayout(1, length_rowTwo));
  JPanel r3 = new JPanel(new GridLayout(1, length_rowThree));
  JPanel r4 = new JPanel(new GridLayout(1, length_rowFour));
  JPanel r5 = new JPanel(new GridLayout(1, length_rowFive));
  // draw out the rows of buttons
  draw(r1, length_rowOne, r2, length_rowTwo, r3, length_rowThree, r4, length_rowFour, r5, length_rowFive);

 }

 // draw rows of buttons
 public void draw(JPanel r1, int s1, JPanel r2, int s2, JPanel r3, int s3, JPanel r4, int s4, JPanel r5, int s5) {
  for (int i = 0; i < s1; i++) {
   JButton currentButton = new JButton(rowOne[i]);
   currentButton.setPreferredSize(new Dimension(100, 50));
   currentButton.addKeyListener(this);
   buttons_rowOne[i] = currentButton;
   r1.add(buttons_rowOne[i]);
  }
  for (int i = 0; i < s2; i++) {
   JButton currentButton = new JButton(rowTwo[i]);
   currentButton.setPreferredSize(new Dimension(100, 50));
   currentButton.addKeyListener(this);
   buttons_rowTwo[i] = currentButton;
   r2.add(buttons_rowTwo[i]);
  }
  for (int i = 0; i < s3; i++) {
   JButton currentButton = new JButton(rowThree[i]);
   currentButton.setPreferredSize(new Dimension(100, 50));
   currentButton.addKeyListener(this);
   buttons_rowThree[i] = currentButton;
   r3.add(buttons_rowThree[i]);
  }
  for (int i = 0; i < s4; i++) {
   JButton currentButton = new JButton(rowFour[i]);
   currentButton.setPreferredSize(new Dimension(100, 50));
   currentButton.addKeyListener(this);
   buttons_rowFour[i] = currentButton;
   r4.add(buttons_rowFour[i]);
  }
  for (int i = 0; i < s5; i++) {
   JButton currentButton = new JButton(rowFive[i]);
   // account for space bar
   if (i == 1) {
    currentButton = new JButton(rowFive[i]);
    currentButton.setPreferredSize(new Dimension(400, 10));
    currentButton.setBounds(10, 10, 600, 100);
    currentButton.addKeyListener(this);
    buttons_rowFive[i] = currentButton;
   } else {
    currentButton.setPreferredSize(new Dimension(100, 50));
    currentButton.addKeyListener(this);
    buttons_rowFive[i] = currentButton;
   }
   r5.add(buttons_rowFive[i]);
  }
  bottom.add(r1);
  bottom.add(r2);
  bottom.add(r3);
  bottom.add(r4);
  bottom.add(r5);
 } // !draw(...)
 // called when a button is pressed

 @Override
 public void keyPressed(KeyEvent press) {
  Object current = press.getKeyChar();
  System.out.println("passed");
  for (int i = 0; i < rowOne.length; i++) {
   if (current == rowOne[i]) {
    buttons_rowOne[i].setBackground(Color.BLACK);
   }
  }
  for (int i = 0; i < rowTwo.length; i++) {
   if (current == rowTwo[i]) {
    buttons_rowTwo[i].setBackground(Color.BLACK);
   }
  }
  for (int i = 0; i < rowThree.length; i++) {
   if (current == rowThree[i]) {
    buttons_rowThree[i].setBackground(Color.BLACK);
   }
  }
  for (int i = 0; i < rowFour.length; i++) {
   if (current == rowFour[i]) {
    buttons_rowFour[i].setBackground(Color.BLACK);
   }
  }
  for (int i = 0; i < rowFive.length; i++) {
   if (current == rowFive[i]) {
    buttons_rowFive[i].setBackground(Color.BLACK);
   }
  }
  repaint();
 } // !keyPressed(...)
 // called when a button is released

 @Override
 public void keyReleased(KeyEvent release) {
  Object current = release.getSource();
  for (int i = 0; i < 10; i++) {
   if (current == rowOne[i]) {
    buttons_rowOne[i].setBackground(defaultColor);
   } else if (current == rowTwo[i]) {
    buttons_rowTwo[i].setBackground(defaultColor);
   } else if (current == rowThree[i]) {
    buttons_rowThree[i].setBackground(defaultColor);
   } else if (current == rowFour[i]) {
    buttons_rowFour[i].setBackground(defaultColor);
   } else if (current == rowFive[i]) {
    buttons_rowFive[i].setBackground(defaultColor);
   }
  }
  repaint();
 } // !keyReleased(...)

 @Override
 public void keyTyped(KeyEvent typed) {
  // Object current = typed.getSource().toString();
  // StringBuilder sb = new StringBuilder();
  // for (int i = 0; i < 14; i++) {
  //   if (current == rowOne[i]) {
  //     sb.append(typed.getKeyCode());
  //     body.append(sb.toString());
  //   } else if (current == rowTwo[i]) {
  //     sb.append(typed.getKeyCode());
  //     body.append(sb.toString());
  //   } else if (current == rowThree[i]) {
  //     sb.append(typed.getKeyCode());
  //     body.append(sb.toString());
  //   } else if (current == rowFour[i]) {
  //     sb.append(typed.getKeyCode());
  //     body.append(sb.toString());
  //   } else if (current == rowFive[i]) {
  //     sb.append(typed.getKeyCode());
  //     body.append(sb.toString());
  //   }
  // }      
 }
 // main method
 public static void main(String[] args) {
  new ButtonInPane();
 } // !main method

 private static final long serialVersionUID = 999;
} // !main class

Answer 1

您的逻辑的一个基本问题是keyPressed中的if语句永远不会为真，这就是为什么print语句有效但背景颜色不变的原因。诸如if (current == rowOne[i])之类的if语句永远不会为真的原因是，current的类型为Object，但是您要为其分配press.getKeyChar()，即char类型的。我猜想这将导致auto-boxing，这意味着char的值将成为Character对象。对于rowOne[i]，由于rowOne中的值都是String类型，因此，对于current来说，它们都是对象，而不是基元。直接将对象与==比较只能确定对象是否是同一对象，这意味着您是在比较引用而不是值。要比较对象，您需要使用a.equals(b)来正确比较对象的值（请参阅"Difference between == and .equals() method in Java"）。

就您而言，这两个问题加在一起导致if语句无法按预期工作。我建议将current声明为char，并使您的数组包含char原语而不是String对象（例如，'A'而不是"A" ）。在这种情况下，您可以使用char直接比较两个==基元，至少可以解决该问题。

希望这会指引您正确的方向。

输入了按键功能，但无法正常运行

1 个答案: