java - 单击告诉它重新绘制的按钮后 Canvas 不会更新

Question

为什么 Grid mze 不更新？这些按钮应该编辑行和列，然后将更新 Grid mze 的单元格，但事实并非如此。如果我点击与 H 对齐的 + 按钮，mze 应该更新为 26x25 网格，但什么也没有发生，只有 Columns + 1 出现在控制台上。

        import javax.swing.*;
import java.awt.*;
import javax.swing.GroupLayout.*;
import javax.swing.LayoutStyle.ComponentPlacement;
import javax.swing.border.LineBorder;
import javax.swing.border.MatteBorder;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class csc extends JFrame{

    public csc(String s){
    super(s);
    setSize(800,600);

    //code generated from eclipse
    JPanel panel = new JPanel();
    panel.setBackground(SystemColor.control);
    GroupLayout groupLayout = new GroupLayout(getContentPane());
    groupLayout.setHorizontalGroup(
        groupLayout.createParallelGroup(Alignment.LEADING)
            .addGroup(groupLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(panel, GroupLayout.DEFAULT_SIZE, 774, Short.MAX_VALUE)
                .addContainerGap())
    );
    groupLayout.setVerticalGroup(
        groupLayout.createParallelGroup(Alignment.LEADING)
            .addGroup(groupLayout.createSequentialGroup()
                .addContainerGap()
                .addComponent(panel, GroupLayout.DEFAULT_SIZE, 550, Short.MAX_VALUE)
                .addContainerGap())
    );

    JPanel scCont = new JPanel();
    scCont.setBorder(new MatteBorder(0, 0, 1, 1, (Color) new Color(0, 0, 0)));

    JPanel cplCont = new JPanel();
    GroupLayout gl_panel = new GroupLayout(panel);
    gl_panel.setHorizontalGroup(
        gl_panel.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_panel.createSequentialGroup()
                .addGap(27)
                .addComponent(scCont, GroupLayout.PREFERRED_SIZE, 475, GroupLayout.PREFERRED_SIZE)
                .addGap(18)
                .addComponent(cplCont, GroupLayout.PREFERRED_SIZE, 235, GroupLayout.PREFERRED_SIZE)
                .addContainerGap(19, Short.MAX_VALUE))
    );
    gl_panel.setVerticalGroup(
        gl_panel.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_panel.createSequentialGroup()
                .addGroup(gl_panel.createParallelGroup(Alignment.LEADING)
                    .addGroup(gl_panel.createSequentialGroup()
                        .addGap(131)
                        .addComponent(cplCont, GroupLayout.PREFERRED_SIZE, 249, GroupLayout.PREFERRED_SIZE))
                    .addGroup(gl_panel.createSequentialGroup()
                        .addGap(35)
                        .addComponent(scCont, GroupLayout.PREFERRED_SIZE, 480, GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(35, Short.MAX_VALUE))
    );
    Grid mze = new Grid(4,4,400,400);
    cscPanel cpl = new cscPanel(this,mze);
    scCont.setLayout(new BorderLayout(0, 0));
    mze = new Grid(cpl.rows,cpl.cols,400,400);
    mze.setForeground(SystemColor.desktop);
    scCont.add(mze);

    GroupLayout gl_cplCont = new GroupLayout(cplCont);
    gl_cplCont.setHorizontalGroup(
        gl_cplCont.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_cplCont.createSequentialGroup()
                .addContainerGap()
                .addComponent(cpl, GroupLayout.DEFAULT_SIZE, 215, Short.MAX_VALUE)
                .addContainerGap())
    );
    gl_cplCont.setVerticalGroup(
        gl_cplCont.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_cplCont.createSequentialGroup()
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(cpl, GroupLayout.PREFERRED_SIZE, 419, GroupLayout.PREFERRED_SIZE))
    );
    cplCont.setLayout(gl_cplCont);
    panel.setLayout(gl_panel);
    getContentPane().setLayout(groupLayout);
    //end of eclipse generated code
    pack();
    setResizable(false);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(EXIT_ON_CLOSE);    
    }

    public static void main(String[] args){
    csc MakeMaze = new csc("Catch Torchic!");
    MakeMaze.setVisible(true);

    }
}

class cscPanel extends JPanel{
  static final int MIN_CELLS = 3;
  static final int MAX_W_CELLS = 50;
  static final int MAX_H_CELLS = 50;
  static final int MAX_DELAY = 500;
  static final int MIN_DELAY = 5;
  int rows = 25; int cols = 25; private int genDelay = 50; private int solveDelay = 50;
  JButton bGen;
  JButton bmm;
  JButton bSolve;
  JButton bLoad;
  JButton bRowsPlus;
  JButton bRowsMinus;
  JButton bColsPlus;
  JButton bColsMinus;
  private TextField tfRows;
  private TextField tfCols;
  private JPanel rowsPanel;
  private JPanel colsPanel;
  private JPanel rowsBtnPanel;
  private JPanel colsBtnPanel;
  private Grid mze;
  private csc Fr;
  private JPanel p = new JPanel();
  private cscButtonHandler handler;

  cscPanel(csc Fr, Grid mze) {
    this.Fr = Fr;
    this.mze = mze;

    setLayout(new GridLayout(11, 1, 0, 3));

    this.rowsBtnPanel = new JPanel();
    this.colsBtnPanel = new JPanel();
    this.rowsBtnPanel.setLayout(new GridLayout(1, 2));
    this.colsBtnPanel.setLayout(new GridLayout(1, 2));
    this.rowsBtnPanel.add(this.bRowsMinus = new JButton("-"));
    this.rowsBtnPanel.add(this.bRowsPlus = new JButton("+"));
    this.colsBtnPanel.add(this.bColsMinus = new JButton("-"));
    this.colsBtnPanel.add(this.bColsPlus = new JButton("+"));
    this.rowsPanel = new JPanel();
    this.rowsPanel.setLayout(new BorderLayout(2, 0));
    this.rowsPanel.add("West", new Label("W"));
    this.rowsPanel.add("Center", this.tfRows = new TextField(3));
    this.rowsPanel.add("East", this.rowsBtnPanel);
    this.colsPanel = new JPanel();
    this.colsPanel.setLayout(new BorderLayout(2, 0));
    this.colsPanel.add("West", new Label("H"));
    this.colsPanel.add("Center", this.tfCols = new TextField(3));
    this.colsPanel.add("East", this.colsBtnPanel);
    this.tfRows.setEditable(false);
    this.tfCols.setEditable(false);

    add(this.bLoad = new JButton("LOAD"));
    add(this.rowsPanel);
    add(this.colsPanel);
    add(this.bGen = new JButton("RANDOM"));
    add(this.bSolve = new JButton("SOLVE"));
    add(this.bmm = new JButton("MAIN MENU"));

    this.tfRows.setText(Integer.toString(this.rows));
    this.tfCols.setText(Integer.toString(this.cols));
    this.bSolve.setEnabled(false);

    handler = new cscButtonHandler(Fr,this,mze);
        bGen.addActionListener(handler);
        bmm.addActionListener(handler);
        bSolve.addActionListener(handler);
        bLoad.addActionListener(handler);
        bRowsPlus.addActionListener(handler);
        bRowsMinus.addActionListener(handler);
        bColsPlus.addActionListener(handler);
        bColsMinus.addActionListener(handler);
  }

  void setPlusMinusEnable() {
    this.bRowsPlus.setEnabled(this.rows < 50);

    this.bRowsMinus.setEnabled(this.rows > 3);

    this.bColsPlus.setEnabled(this.cols < 50);

    this.bColsMinus.setEnabled(this.cols > 3);
  }

  void setGenEnable(boolean paramBoolean){
    this.bGen.setEnabled(paramBoolean); } 

  void setSolveEnable(boolean paramBoolean) { this.bSolve.setEnabled(paramBoolean); }
}

class cscButtonHandler implements ActionListener{
    csc a;
    cscPanel b;
    Grid c;

    public cscButtonHandler(csc a,cscPanel b, Grid c){
        this.a = a;
        this.b = b;
        this.c = c;
    }

    public void actionPerformed(ActionEvent e){
        if(e.getSource() == b.bmm)
            {System.out.println("Back to MainMenu");}
        else if(e.getSource() == b.bSolve)
            {System.out.println("Solve Maze");}
        else if(e.getSource() == b.bLoad)
            {System.out.println("Open Load Dialog");}
        else if(e.getSource() == b.bRowsPlus)
            {System.out.println("Rows + 1");
             b.rows++;
             c.repaint(b.rows,b.cols,400,400);}
        else if(e.getSource() == b.bRowsMinus)
            {System.out.println("Rows - 1");
             b.rows--;
             c.repaint(b.rows,b.cols,400,400);}
        else if(e.getSource() == b.bColsPlus)
            {System.out.println("Columns + 1");
             b.cols++;
             c.repaint(b.rows,b.cols,400,400);}
        else if(e.getSource() == b.bColsMinus)
            {System.out.println("Columns - 1");
             b.cols--;
             c.repaint(b.rows,b.cols,400,400);}
        else if(e.getSource() == b.bGen)
            {System.out.println("Generating Randomly");}
    }

}
class Grid extends Canvas{

    Cell[][] maze;
    int rows;
    int cols;

    public Grid(int rows, int cols, int h, int w) {
        this.rows = rows;
        this.cols = cols;
        maze = new Cell[rows][cols];
        setPreferredSize(new Dimension(h,w));
    }

    public void paint(Graphics g) {
        int k;
        double width = getSize().width;
        double height = getSize().height;

        double htOfRow = height / (rows);
        for (k = 0; k < rows; k++)
            g.drawLine(0, (int) (k * htOfRow) , (int) width, (int) (k * htOfRow) );

        double wdOfRow = width / (cols);
        for (k = 0; k < cols; k++)
            g.drawLine((int) (k*wdOfRow) , 0,(int) (k*wdOfRow) , (int) height);
    }
}

class Cell {}

Answer 1

这段代码有一些问题，但至少我可以看到重绘的一个问题是对 repaint 的调用正在传递看起来像网格单元格坐标的东西，而实际上 repaint 接受像素坐标。