鼠標座標停止工作後，使用翻譯recallibrate協調系統-java

Question

我正在開發一個座標系，點（0,0）將位於面板的中心，但在翻譯默認（0,0）座標後，鼠標座標停止顯示。如果沒有這行代碼「ga.translate（175.0，125.0）」，該程序將工作。如何解決此問題？謝謝。

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 
import java.awt.event.MouseMotionListener; 
import javax.swing.JLabel; 

public class Main extends JPanel implements MouseMotionListener { 
    public JLabel label; 
    //@Override 
    protected void paintComponent(Graphics g) { 
     super.paintComponent(g); 
     Graphics2D ga = (Graphics2D) g; 
     ga.translate(175.0, 125.0); //the mouse coordinates stop displaying with this code 
     ga.drawLine(0, 0, 100, 100); 
    } 
    public static void main(String[] args) { 
     Main m = new Main(); 
     GraphicsDraw D = new GraphicsDraw(); 
     JFrame frame = new JFrame(); 
     frame.setTitle("MouseCoordinates111"); 
     frame.setSize(400, 400); 
     frame.addWindowListener(new WindowAdapter() { 
      public void windowClosing(WindowEvent we) { 
       System.exit(0); 
      } 
     }); 
     Container contentPane = frame.getContentPane(); 
     contentPane.add(m); 
     frame.setVisible(true); 
    } 
    public Main() { 
     setSize(400, 400); 
     label = new JLabel("No Mouse Event Captured", JLabel.CENTER); 
     add(label); 
     //super(); 
     addMouseMotionListener(this); 

    } 
    @Override 
    public void mouseMoved(MouseEvent e) { 
     //System.out.println(e.getX() + "/" + e.getY()); 
     label.setText("Mouse Cursor Coordinates => X:" + e.getX() + " |Y:" + e.getY()); 
    } 
    @Override 
    public void mouseDragged(MouseEvent e) {} 
    public void mouseClicked(MouseEvent e) { 
     int x = e.getX(); 
     int y = e.getY(); 

    } 

} 

Answer 1

當你操縱Graphics對象的（某些）值（如翻譯，轉換），你應該總是恢復到原來的狀態。

一個簡單的方法做，這是創建一個臨時Graphics對象做你的畫：

@Override 
protected void paintComponent(Graphics g) 
{ 
    super.paintComponent(g); 

    //Graphics2D ga = (Graphics2D) g; 
    Graphics2D ga = (Graphics2D)g.create(); 

    ga.translate(175.0, 125.0); //the mouse coordinates stop displaying with this code 
    ga.drawLine(0, 0, 100, 100); 

    ga.dispose(); 
}