小编Wef*_*ksd的帖子

我正在创建一个矩形绘图程序.仅当程序拖动到底部时才绘制正方形.即使向另一个方向拖动,我也希望确保正确绘制正方形.我该如何解决？请帮我.

**DrawRect.java**


    import javax.swing.*;

    import java.awt.*;

    import java.awt.event.*;

    public class DrawRect extends JPanel {

        int x, y, w, h;
        public static void main(String [] args) { 
            JFrame f = new JFrame("Draw Box Mouse 2");
            f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
            f.setContentPane(new DrawRect());
            f.setSize(300, 300); f.setVisible(true);
        }



        DrawRect() { 
            x = y = w = h = 0; // 
            MyMouseListener listener = new MyMouseListener(); 
            addMouseListener(listener); 
            addMouseMotionListener(listener);    
        }

        public void setStartPoint(int x, int y) {
            this.x = x; this.y = y;
        }

        public void setEndPoint(int x, int …