重绘（）后如何保持在图形g中绘制的文本

Question

public class Drawing extends JPanel {

int Mouse_x = 0, Mouse_y = 0;

@Override
protected void paintComponent(Graphics g) {
    // TODO Auto-generated method stub
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;
    this.setOpaque(true);
    this.setBackground(Color.WHITE);
    g2.drawString(Mouse_x + "," + Mouse_y, Mouse_x, Mouse_y);
}
}

如何在框架上保存此文本，并在需要时清除所有框架。 例：

Answer 1

你使用鼠标坐标吗？您可以使用鼠标监听器并使用鼠标单击方法（鼠标单击后，它将使您的字符串生成x，y坐标。）

public void createDot(int x, int y){
   g.drawString(Mouse_x + "," + Mouse_y, x, y);
}

您必须添加addMouseListener(this);并实施其方法。我只写了mouseClicked方法

public void mouseClicked(MouseEvent e) {
    int x = e.getX();
    int y = e.getY();

    createDot(x,y);

}

protected void paintComponent(Graphics g) {
    // TODO Auto-generated method stub
    super.paintComponent(g);
    Graphics2D g2 = (Graphics2D) g;

}

并且您的GUI在另一个方法中创建：例如

public static void createGUI(){
    JFrame frame = new JFrame("My Frame");
    JComponent component = new Drawing();
    component.setOpaque(true);
    frame.add(component);
    frame.setSize(600,400);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

}

然后在main方法中运行：

public static void main(String [] args){
            createGUI();
        }