从Java中的Jtextfield输入中绘制一个2D矩形

Question

我目前正在Java开发GUI。在这种情况下，我试图在JPanel中显示一个名为drawpanel的jpanel中的2D矩形。为了做到这一点，我创建了一个名为die的类，并初始化了paintcomponent和actionperformed方法。在Action Performed中，我从JTEXTFIELDS中解析了双打，这将是我的2D矩形的输入。然后，我继续绘制矩形，最后将其连接到drawpanel。问题在于drawpanel.draw（rect）给我一个错误，特别是在draw（rect）中。此错误阻止其绘制2D矩形。我想知道是否有人可以帮助我确定我遇到的问题。此外，我还有几个问题：

• 我的覆盖是否放在正确的行（位置）中？
• 是否有一种更简单的方法来达到我计划的相同结果？ 提前致谢！任何输入都非常感谢。我在下面附上了我的代码。这不是整个代码，因为我开发的GUI很长。但是，如果需要更多的代码才能理解问题，请随时要求它！

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);
    drawpanel.draw(rect);
    
  }
}

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

为了解释drawpanel的来源：

这是通过继承方法kpackage创建的JPANEL，这是创建的2D图。添加的drawpanel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(); 

然后，kpackage（）的代码在这里：

public class Kpackage extends JPanel{
   @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));

   }}

Answer 1

扩展我的评论。要完成这项工作，您需要做几件事：

1. 将Draw方法添加到kpackage类，该类接受A Rectangle2D作为输入，例如So public> public void draw（Rectangle2d rect）{...}，这将修复您的初始错误。

2. 在您的kpackage类中创建一个可以存储矩形arrayList＆lt; rectangle2d＆gt; gt;的类变量。矩形= new arraylist＆lt;＆gt;（）;

3. 在绘制方法中，将输入的矩形保存到arrayList中，然后调用repaint（）;

   >

4. 现在的技巧是paintcomponent方法必须循环循环矩形列表在阵列列表中并相应地绘制每个列表。

这是Kpackage类可能会看起来像所有上述所有操作的样子：

public class Kpackage extends JPanel{
    //List of added rectangles
    private ArrayList<Rectangle2D > rectangles = new ArrayList<>();
    
    //Draw method to insert a new rectangle
    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();
    }
    
    //Overridden method that actually pantis the rectangles
    @Override
    public void paintComponent(Graphics g){
        //Call super to paint the JPanel before anything else
        super.paintComponent(g);
        
        //Get the 2D graphics
        Graphics2D g2d = (Graphics2D) g;

        //Now paint any borders or custom items
        //...
        //your code here
        //etc
        
        //Finally paint the rectangles saved in the list
        for (Rectangle2D rectangle : rectangles){
            //Draw a basic rectangle, just as proof that this works
            g2d.draw(rectangle);
            
            //You will actually do custom drawing scaled to fit your Kpackage here
            //But I removed it for clarity, you can play with this section to make it work
            //Get sizes and scales
            //...

            //Draw sides
            //...

            //Fill rectangle
            //...

            //etc, etc
        }
    }
}

用法将与您在Action Perperformed方法中的使用情况完全一样：

//drawing the rectangle
Rectangle2D rect = new Rectangle2D.Double(x, y, width, length);
drawpanel.draw(rect);