Java GUI:重新绘制（）或类交互问题

因此，我正在创建一个海龟图形项目，当给定命令输入时，我很难让海龟移动。下面是两个交互类，处理用户输入的my TextPanel类和包含可绘制的“canvas”等的GraphicsPanel

由于我目前没有收到任何错误，我想知道我是否正确调用了GraphicsPanel类，或者我使用的是repaint（），而它是错误的方法？我不知所措，需要一双新眼睛。谢谢你抽出时间

public class TextPanel extends JPanel implements ActionListener {

private JTextArea textArea;
private JScrollPane scrollPane;
private JTextField commField;
private JButton enterBut;
private TextListener textListener;
private GraphicsPanel graphicsPanel;

//***********//
//CONSTRUCTOR//
//***********//

public TextPanel() {

    textArea = new JTextArea();
    scrollPane = new JScrollPane ( textArea );
    enterBut = new JButton("Execute");
    commField = new JTextField(10);
    graphicsPanel = new GraphicsPanel();


    textArea.setLineWrap(true);         //stops text from going outside
    textArea.setWrapStyleWord(true);    //panel boundaries

    //**********************//
    //COMMAND IMPLEMENTATION//
    //**********************//

    commField.addActionListener(new ActionListener() {


        public void actionPerformed(ActionEvent e) {

            if(commField.getText().contains("penup")) {
                GraphicsPanel.penUp();
            }
            else if(commField.getText().contains("pendown")) {
                GraphicsPanel.penDown();
            }
            else if(commField.getText().contains("turnright")) {
                GraphicsPanel.turnRight();
            }
            else if(commField.getText().contains("turnleft")) {
                GraphicsPanel.turnLeft();
            }
            else if(commField.getText().startsWith("forward")) {        //getText method retrives user input from JTextField
                String cForward = commField.getText();                  //<startsWith> searches string for desired command
                String[] cForwardArray = cForward.split("\\s+");        //string array created and split with " " as split
                try {
                    int distance = Integer.parseInt(cForwardArray[1]);  //parseInt takes the integer from string split
                    GraphicsPanel.forward(distance);                    //GraphicsPanel command called + distance integer
                    textArea.append(cForward + "\n");           //test for variable values
                    GraphicsPanel.validate();
                    GraphicsPanel.repaint();                            //canvas is repainted 


                } 
                catch (Exception ev) {
                    JOptionPane.showMessageDialog(textArea, 
                            "Invaild or missing parameter, check the help section\n"
                            + "for more information on Commands");
                }
            }
            else if(commField.getText().startsWith("backward")) {
                String cBackward = commField.getText();
                String[] cBackwardArray = cBackward.split("\\s+");
                try {
                    int distance = Integer.parseInt(cBackwardArray[1]);
                    GraphicsPanel.backward(distance);
                    textArea.append(cBackward +"\n");
                    GraphicsPanel.repaint();
                } 
                catch (Exception ev) {
                    JOptionPane.showMessageDialog(textArea, 
                            "Invaild or missing parameter, check the help section\n"
                            + "for more information on Commands");
                }
            }

            else if(commField.getText().contains("black")) {
                GraphicsPanel.black(Color.black);
            }
            else if(commField.getText().contains("green")) {
                GraphicsPanel.green(Color.green);
            }
            else if(commField.getText().contains("red")) {
                GraphicsPanel.red(Color.red);
            }
            else if(commField.getText().contains("reset")) {
                GraphicsPanel.clear();
            }
            else {
                JOptionPane.showMessageDialog(textArea, "Invalid command, try again");
            }

            commField.setText("");
            GraphicsPanel.repaint();


        }
    });


    //****************//
    //PANEL DIMENSIONS//
    //****************//

    setBackground(Color.black);

    Dimension dim = getPreferredSize();     //sets dimensions of panel
    dim.width = 250;
    setPreferredSize(dim);

    //setBorder(BorderFactory.createTitledBorder("Enter Commands here: "));
    //setTitleColor(Color.white); //not sure why this doesnt change the text colour


    //**************//
    //GRIDBAG LAYOUT//
    //**************//

    setLayout(new GridBagLayout());
    GridBagConstraints constraint = new GridBagConstraints();

    add(commField, constraint);

    constraint.fill = GridBagConstraints.HORIZONTAL;
    constraint.ipady = 20;
    constraint.ipadx = 60;
    constraint.insets = new Insets(10, 5, 0, 0);
    constraint.weightx = 1;
    constraint.weighty = 0;
    constraint.gridx = 0;                           //grid position
    constraint.gridy = 0;

    add(commField, constraint);
    //***********************//

    constraint.fill = GridBagConstraints.HORIZONTAL;
    constraint.ipady = 15;
    constraint.ipadx = 25;
    constraint.anchor = GridBagConstraints.PAGE_END;    //anchors to bottom of GUI
    constraint.insets = new Insets(10, 0, 0, 0);        //inserts gap
    constraint.weightx = 0;
    constraint.weighty = 0;
    constraint.gridx = 1;                       
    constraint.gridy = 0;

    add(enterBut, constraint);

    //*************************//

    constraint.fill = GridBagConstraints.BOTH;      //option how to fill 'cell' 
    constraint.ipady = 150;                         //dim of component 
    constraint.ipadx = 150;
    constraint.insets = new Insets(0, 5, 0, 0);
    constraint.gridwidth = 3;                       //how many grid cell it spans
    constraint.weightx = 1;                         //precedent for space
    constraint.weighty = 1;
    constraint.gridx = 0;                           //grid position
    constraint.gridy = 1;

    add(new JScrollPane(textArea), constraint);                     //adds component
                                                                    //and JSCrollPane
    //************************//

    //**NOTES****************************//
    //next time use smaller variable name//
    //***********************************//

}


private void setTitleColor(Color white) {


}

public void appendText(String text) {

}


@Override
public void actionPerformed(ActionEvent e) {


}

public void setTextListener(textListener listener) {
    this.TextListener = listener;
}
}

公共类TextPanel扩展JPanel实现ActionListener{
私人JTEXTEXTAREA textArea；
私有JScrollPane滚动窗格；
私有JTextField commField；
私人JButton enterBut；
私有文本监听器；
专用图形面板GraphicsPanel；
//***********//
//建造师//
//***********//
公共文本面板（）{
textArea=新的JTextArea（）；
scrollPane=新的JScrollPane（textArea）；
enterBut=新的JButton（“执行”）；
commField=新的JTextField（10）；
graphicsPanel=新的graphicsPanel（）；
textArea.setLineWrap（true）；//阻止文本向外移动
textArea.setWrapStyleWord（true）；//面板边界
//**********************//
//命令执行//
//**********************//
commField.addActionListener（新ActionListener（）{
已执行的公共无效操作（操作事件e）{
if（commField.getText（）包含（“penup”））{
GraphicsPanel.penUp（）；
}
else if（commField.getText（）包含（“pendown”））{
GraphicsPanel.penDown（）；
}
else if（commField.getText（）包含（“右转”））{
图形spanel.turnRight（）；
}
else if（commField.getText（）包含（“左转”））{
图形spanel.左转（）；
}
else if（commField.getText（）.startsWith（“forward”）{//getText方法从JTextField检索用户输入
String cForward=commField.getText（）；//在字符串中搜索所需的命令
String[]cForwardArray=cForward.split（\\s+”）；//创建字符串数组并将“”作为拆分进行拆分
试一试{
int distance=Integer.parseInt（cForwardArray[1]）；//parseInt从字符串拆分中获取整数
GraphicsPanel.forward（distance）；//GraphicsPanel命令称为+distance整数
textArea.append（cForward+“\n”）；//测试变量值
GraphicsPanel.validate（）；
GraphicsPanel.repaint（）；//画布已重新绘制
} 
捕获（例外ev）{
JOptionPane.showMessageDialog（文本区域，
Invaild或缺少参数，请检查“帮助”部分\n
+“有关命令的更多信息”）；
}
}
else if（commField.getText（）.startsWith（“向后”））{
字符串cBackward=commField.getText（）；
字符串[]cBackwardArray=cBackward.split（\\s+）；
试一试{
int distance=Integer.parseInt（cBackwardArray[1]）；
图形向后（距离）；
textArea.append（cBackward+“\n”）；
GraphicsPanel.repaint（）；
} 
捕获（例外ev）{
JOptionPane.showMessageDialog（文本区域，
Invaild或缺少参数，请检查“帮助”部分\n
+“有关命令的更多信息”）；
}
}
else if（commField.getText（）包含（“黑色”））{
图形面板。黑色（颜色。黑色）；
}
else if（commField.getText（）包含（“绿色”））{
图形。绿色（颜色。绿色）；
}
else if（commField.getText（）包含（“红色”））{
图形。红色（颜色。红色）；
}
else if（commField.getText（）包含（“重置”））{
GraphicsPanel.clear（）；
}
否则{
showMessageDialog（文本区域，“无效命令，请重试”）；
}
commField.setText（“”）；
GraphicsPanel.repaint（）；
}
});
//****************//
//面板尺寸//
//****************//
挫折背景（颜色：黑色）；
Dimension dim=getPreferredSize（）；//设置面板的尺寸
尺寸宽度=250；
设置首选大小（dim）；
//setBordOrder（BorderFactory.createTitledBorder（“在此处输入命令：”）；
//setTitleColor（Color.white）；//不确定为什么这不会更改文本颜色
//**************//
//网格布局//
//**************//
setLayout（新的GridBagLayout（））；
GridBagConstraints constraint=新的GridBagConstraints（）；
添加（commField，constraint）；
constraint.fill=gridbagsconstraints.HORIZONTAL；
constraint.ipady=20；
constraint.ipadx=60；
constraint.insets=新的插入（10,5,0,0）；
constraint.weightx=1；
constraint.weighty=0；
constraint.gridx=0；//网格位置
constraint.gridy=0；
添加（commField，constraint）；
//***********************//
constraint.fill=gridbagsconstraints.HORIZONTAL；
constraint.ipady=15；
constraint.ipadx=25；
constraint.anchor=GridBagConstraints.PAGE_END；//定位到GUI底部
constraint.insets=新插入（10,0,0,0）；//插入间隙
constraint.weightx=0；
constraint.weighty=0；
constraint.gridx=1；
constraint.gridy=0；
添加（输入、约束）；
//*************************//
constraint.fill=GridBagConstraints.BOTH；//选项如何填充“单元格”
constraint.ipady=150；
@SuppressWarnings("serial")                     //Represents the graphics display panel
                                                //panel within the turtle program. 
public class GraphicsPanel extends JPanel {     //This panel contains an image which 
                                                //is updated to reflect user commands.



//background colour image



private final static Color BACKGROUND_COL = Color.DARK_GRAY;
private final static int TURTLE_X_SIZE = 20, TURTLE_Y_SIZE = 20;

private TextPanel TextPanel;
//private JTextField getTextField();

private BufferedImage image, turtleDisplay;     //The underlying image used 
                                                //for drawing. This is required


//Djm added
private Color PenColour = Color.GREEN;          //so any previous drawing activity is 
private boolean penDown = false;                //is persistent on the panel.
private int xPos=325, yPos=180;
private int direction = 180;                    //robot pointing down the screen;




//change drawLine colour

public void black(Color color) {
    color = Color.black;
}

public void green(Color color) {
    color = Color.green;
}

public void red(Color color) {
    color = Color.red;
}

public void drawLine(Color color, int x1, int y1, int x2, int y2) {

    Graphics g = image.getGraphics();
    g.setColor(color);
    g.drawLine(x1, y1, x2, y2);
}


public void penDown() {
    penDown = true;
}

//***********************************//

public void penUp() {
    penDown = false;
}

//***********************************//

public void turnRight() {
    direction +=90;
    if (direction >= 360)
        direction = 0;
}

//***********************************//

public void turnLeft() {
    direction -=90;
    if (direction < 0)
        direction = 270;
}

//***********************************//


//sends the turtle forward

public void forward(int distance) {
                                    //Graphics g = image.getGraphics();
    int x=xPos,y=yPos;
                                    //stored xPos and yPos are current location

    if (direction == 0) {           //robot facing up the screen, so forward subtracts y
        y = yPos-distance;
    }
    else if (direction == 90) {     //robot facing right so forward add x
        x = xPos + distance;
    }
    else if (direction == 180) {     //robot facing down the screen, so forwards adds to y
        y = yPos + distance;
    }
    else if (direction == 270) {    //robot facing left, so forwards subtracts from x
        x = xPos - distance;
    }
    else {
        System.out.println("strange, shouldn't get here");
    }
    if (penDown) {
                                            //x=400; y=400;
        drawLine(PenColour, xPos, yPos, x, y);
                                            //g.drawLine(xPos,yPos,x,y);
    }
                                            //now robot has moved to the new position
    xPos = x;
    yPos = y;
}

//***********************************//

//sends the turtle backwards

public void backward(int distance) {

    int x=xPos,y=yPos;
    //stored xPos and yPos are current location

    if (direction == 0) {           //robot facing up the screen, so forward adds y
        y = yPos + distance;
    }
    else if (direction == 90) {     //robot facing right so forward subtract x
        x = xPos - distance;
    }
    else if (direction == 180) {     //robot facing down the screen, so forwards subtracts to y
        y = yPos - distance;
    }
    else if (direction == 270) {    //robot facing left, so forwards adds from x
        x = xPos + distance;
    }
    else {
        System.out.println("strange, shouldn't get here");
    }
    if (penDown) {
                                                            //x=400; y=400;
        drawLine(PenColour, xPos, yPos, x, y);
                                                            //g.drawLine(xPos,yPos,x,y);
    }
                                                            //now robot has moved to the new position
    xPos = x;
    yPos = y;

}

//***********************************//

 //Clears the image contents.

public void clear() {

    Graphics g = image.getGraphics();
    g.setColor(BACKGROUND_COL);
    g.fillRect(0, 0, image.getWidth(),  image.getHeight());
}

//***********************************//


public void setTurtleColour(Color col) {
    Graphics g = turtleDisplay.getGraphics();
    g.setColor(col);
    g.fillRect(0, 0, turtleDisplay.getWidth(),  turtleDisplay.getHeight());
}

@Override
public void paintComponent(Graphics g) 
{


    super.paintComponent(g);

    // render the image on the panel.
    g.drawImage(image, 0, 0, null);
    g.drawImage(turtleDisplay, xPos-TURTLE_X_SIZE/2, yPos-TURTLE_Y_SIZE/2, null);

}



//***********//
//CONSTRUCTOR//
//***********//

public GraphicsPanel() {

    //main drawing area
    image = new BufferedImage(650, 400, BufferedImage.TYPE_INT_RGB);


    //small image to display on top of drawing area to represent the turtle
    turtleDisplay =  new BufferedImage(20, 20, BufferedImage.TYPE_INT_RGB);

    //set up turtle
    setTurtleColour(PenColour);

    // Set max size of the panel, so that is matches the max size of the image.
    setMaximumSize(new Dimension(image.getWidth(), image.getHeight()));
    setSize(800,400);
    setVisible(true);

    clear();
}