如何更新相应的jpanel中的2D矩形图

Question

我遇到了一个问题，即我的工作代码能够在jpanel drawpanel 给定的输入参数中显示矩形。但是，在尝试创建一个新的矩形时，该新矩形将添加到图纸中。因此，现在我有两个矩形，而不仅仅是更新的矩形。我想知道是否有人可以帮助我确定为什么矩形又一个接一个地出现，而不是只显示一个新更新的矩形。为了更好地说明我的问题，这是一个图像：

“ nofollow noreferrer”>“ nofollow noreferrer”> restate按钮在这里是矩形的创建，但是每次我更改参数时，都会创建一个新的矩形。

这是我的类 die 创建的代码，该代码从JTEXTFIELDS中提取双倍，并创建一个2DDRECTANGLE。

class die extends JPanel implements ActionListener{
  @Override
  protected void paintComponent(Graphics g){
  super.paintComponent(g);
 
  }
  @Override
  public void actionPerformed(ActionEvent e) {
    //parsing double values from jtextfields
  
    double xcor = Double.parseDouble(xcoorin.getText()); 
    double ycor = Double.parseDouble(ycoorin.getText());
    double lengthdie = Double.parseDouble(Die_L.getText());
    double widthdie = Double.parseDouble(Die_W.getText());
    //drawing the rectangle
    Rectangle2D rect = new Rectangle2D.Double(xcor, ycor, widthdie, lengthdie);
    ((Kpackage) drawpanel).draw(rect);
  }
}

ActionListener listen = new die();
locate.addActionListener(listen);

下面是创建JPANEL drawpanel 的代码，该代码是通过继承2D图的方法Kpackage创建JPANEL的地方。添加的绘制板的代码如下：

public class MyFrame{

public MyFrame(){

//Creating new panels for the content window "Frame"
JPanel cyanpanel = new JPanel();
JPanel orangepanel = new JPanel();
JPanel greenpanel = new JPanel();
JPanel magentapanel = new JPanel();
JPanel whitepanel = new JPanel();
JPanel graypanel = new JPanel();
JPanel drawpanel = new Kpackage(); //inheriting information from my panel which is the 2D drawing
JPanel dieinputpanel = new JPanel();
JPanel diepanel = new JPanel();

kpackage（）的代码; 在下面，此代码显示较大的图形，该图形限制了较小的矩形：

public class Kpackage extends JPanel{

private ArrayList<Rectangle2D> rectangles = new ArrayList<>();

  public void draw(Rectangle2D rect){
    //Save the new rectangle to the list
    rectangles.add(rect);
    //Trigger a repaint which will call the paintComponent method and draw all the rectangles
    repaint();
}

   @Override
   public void paintComponent(Graphics g) {
       super.paintComponent(g);
       Graphics2D g2d = (Graphics2D) g;
       g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
       Dimension size = this.getSize();

//Dimensions and variables for the package
       double scale = 30; //scale of the k package

       double aTO_4L = 1.42*scale;
       double bTO_4L = 0.30*scale;
       double cTO_4L = 5.99*scale;
       double dTO_4L = 3.00*scale;
       double d1TO_4L = 1.5*scale;
       double d2TO_4L = 2.60*scale;
       double eTO_4L = 7.26*scale;
       double fTO_4L = 0.64*scale;
       double gTO_4L = 7.18*scale;
       double hTO_4L = 0.38*scale;
       double iTO_4L = 7.79*scale;
       double jTO_4L = 13.26*scale;
       double kTO_4L = 3.78*scale;
       double dia_inner = 3.58*scale;
       double dia_outer = 7.18*scale;
       double tot_width=jTO_4L+2*hTO_4L;
       double tot_height=iTO_4L+eTO_4L+d1TO_4L;
       double x = (size.width/2);
       double y = (size.height/2);

//creating the K package envelope

     g2d.draw(new Line2D.Double(x-cTO_4L/2-aTO_4L, y-eTO_4L-d1TO_4L, x-cTO_4L/2,y-eTO_4L-d1TO_4L ));
     g2d.draw(new Line2D.Double( x-cTO_4L/2,y-eTO_4L-d1TO_4L ,x-cTO_4L/2,y-eTO_4L-d1TO_4L +bTO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2,y-eTO_4L-d1TO_4L +bTO_4L,x-cTO_4L/2+cTO_4L,y-eTO_4L-d1TO_4L+bTO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L,y-eTO_4L-d1TO_4L+bTO_4L,x-cTO_4L/2+cTO_4L,y-eTO_4L-d1TO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L,y-eTO_4L-d1TO_4L,x-cTO_4L/2+cTO_4L+aTO_4L,y-eTO_4L-d1TO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L+aTO_4L,y-eTO_4L-d1TO_4L,x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L,y-eTO_4L-d1TO_4L+d1TO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L,y-eTO_4L-d1TO_4L+d1TO_4L,x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L,x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L-hTO_4L,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L));
     g2d.draw(new Line2D.Double(x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L-hTO_4L,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L,x-cTO_4L/2+cTO_4L+aTO_4L+d2TO_4L-hTO_4L,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L+iTO_4L));
     g2d.draw(new Line2D.Double(x+jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L+iTO_4L,x-jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L+iTO_4L));
     g2d.draw(new Line2D.Double(x-jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L+iTO_4L,x-jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L));
     g2d.draw(new Line2D.Double(x-jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L+iTO_4L,x-jTO_4L/2,y-eTO_4L-d1TO_4L+d1TO_4L+eTO_4L));
     g2d.draw(new Line2D.Double(x-jTO_4L/2,y,x-jTO_4L/2-hTO_4L,y));
     g2d.draw(new Line2D.Double(x-jTO_4L/2-hTO_4L,y,x-jTO_4L/2-hTO_4L,y-eTO_4L));
     g2d.draw(new Line2D.Double(x-jTO_4L/2-hTO_4L,y-eTO_4L,x-jTO_4L/2-hTO_4L+d2TO_4L,y-eTO_4L-d1TO_4L));
     g2d.draw(new Ellipse2D.Double(x-dia_inner/2,y-dia_inner/2-kTO_4L,dia_inner,dia_inner));
     g2d.draw(new Ellipse2D.Double(x-dia_outer/2,y-dia_outer/2-kTO_4L,dia_outer,dia_outer));

//creating the 4 leg leads 

//variables and names
    
    double D_lead = 2.529*scale;
    double S_lead = 4.770*scale;
    double K_lead=1.5*scale;
    double G_lead=2.080*scale;


    double S_p1=1.1*scale;
    double S_p2=4.270*scale;
    double S_p3=0.940*scale;
    double S_p4=2.630*scale;
    double S_rad=0.5*scale;
    
    double lead_w=1.2*scale;
    double lead_h=1.6*scale;

    double K_p1=0.32*scale;
    double K_p2=1.5*scale;
    double K_p3=0.620*scale;
    
    double G_p1=0.880*scale;

    double length_lead=3.0*scale;

    double dist_1=0.178*scale;
    double dist_2=0.450*scale;
    double dist_3=0.720*scale;
    double dist_4=0.4*scale;

 //Creating the lead positions and dimensions

 //Drawing D LEAD

 g2d.draw(new Line2D.Double(x-jTO_4L/2,y+iTO_4L,x-jTO_4L/2,y+iTO_4L+length_lead));
 g2d.draw(new Line2D.Double(x-jTO_4L/2+D_lead,y+iTO_4L,x-jTO_4L/2+D_lead,y+iTO_4L+length_lead));

  //Drawing G LEAD
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_p1,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead,y+iTO_4L+dist_1));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead,y+iTO_4L+dist_1+length_lead));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_p1,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_p1,y+iTO_4L+dist_1+length_lead));


 //Drawing K LEAD
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead-dist_3,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2,y+iTO_4L+dist_1));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p3,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p3,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p3,y+iTO_4L+dist_1+length_lead));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1,y+iTO_4L+dist_1+length_lead));

 //Drawing S LEAD

 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4,y+iTO_4L+dist_1));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4,y+iTO_4L+dist_1,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_p2,y+iTO_4L+dist_1));

 //connect before end point and after start point
 g2d.draw(new Arc2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2,y+iTO_4L+dist_1,2*S_rad,2*S_rad,90, 90,Arc2D.OPEN));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2,y+iTO_4L+dist_1+S_rad,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_p3,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_p3,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_p3,y+iTO_4L+dist_1+length_lead));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2+S_p4,y+iTO_4L+dist_1+lead_h));
 g2d.draw(new Line2D.Double(x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2+S_p4,y+iTO_4L+dist_1+lead_h,x+jTO_4L/2-dist_2-G_lead-dist_3-K_p2-K_p1-dist_4-S_rad-S_p2+S_p4,y+iTO_4L+dist_1+length_lead));


for (Rectangle2D rectangle : rectangles){
  //Draw a basic rectangle, just as proof that this works
 g2d.draw(rectangle);

   }}}

注意：这是我以前的以前的延续问题。链接在这里：

感谢您的帮助！期待每个人的回应。

Answer 1

问题在于，您将每个矩形添加到列表中，最后打印整个列表。如果您只想要一个矩形，请删除列表并更新rettangle2d的单个实例。

您在这里添加矩形。

private ArrayList<Rectangle2D> rectangles = new ArrayList<>();

public void draw(Rectangle2D rect){
    //Save the new rectangle to the list
    rectangles.add(rect);
    //Trigger a repaint which will call the paintComponent method and draw all the rectangles
    repaint();
}

每次在这里打印全部。

for (Rectangle2D rectangle : rectangles){
  //Draw a basic rectangle, just as proof that this works
      g2d.draw(rectangle);
}