我有一个小问题 - 怎样能在主类中从其他类/文件/方法中重新绘制JPanel？
我的情况是这样的，我有一个Swing窗口，它有一列表格的方法。这些方法是通过查找文件和类并读取它们的描述（注释）而自动生成的。现在，当来自某个类的一个方法需要用圆和线绘制太阳时，我该如何让它显示在主窗口中呢？
我查阅了相关资料（Google），发现JPanel很方便，但从另一个类或方法中画上去，不知道它们的名称以及何时使用该画图，会产生困难。
如果有用的话，我也添加了主方法。
static int indez = 0;
protected static JList list;
static boolean valitud = false;
public static JTextArea txtala;
public static JScrollPane scrl;
public static JPanel pilt;
static Map<Integer, String[]> info = new TreeMap<Integer, String[]>();
static ArrayList<Integer> nrs = new ArrayList<Integer>();
public static void main(String[] args){
Iterator<Entry<Integer, String[]>> iterator;
Entry<Integer, String[]> entry;
Integer val = 0;
JFrame f = new JFrame("Praktikumid");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(750, 350);
JPanel panel = new JPanel();
pilt = new JPanel(){public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawString("This is my custom Panel!", 10, 20);
}};
pilt.setVisible(false);
pilt.setPreferredSize(new Dimension(f.getWidth() - 200, f.getHeight() - 20));
pilt.setBackground(Color.GRAY);
GroupLayout layout = new GroupLayout(panel);
panel.setLayout(layout);
layout.setAutoCreateGaps(true);
layout.setAutoCreateContainerGaps(true);
ActionListener kuular = new ActionListener() {
public void actionPerformed(ActionEvent tegu) {
valitud = true;
try {
praxStarter();
} catch (Exception e) {
e.printStackTrace();
}
}
};
MouseListener hiir = new MouseListener() {
public void mouseClicked(MouseEvent e) {
indez = list.getSelectedIndex();
}
@Override
public void mouseEntered(MouseEvent e) {}
@Override
public void mouseExited(MouseEvent e) {}
@Override
public void mousePressed(MouseEvent e) {}
@Override
public void mouseReleased(MouseEvent e) {}
};
JLabel kiri = new JLabel("Vali hiirega ja vajuta nupule");
ArrayList<String> selections = new ArrayList<String>();
// Iterating over all the items in another method to get the modules
list = new JList(selections.toArray());
list.setSelectedIndex(0);
list.addMouseListener(hiir);
JScrollPane listScroller = new JScrollPane(list, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
listScroller.setMinimumSize(new Dimension(200, 50));
listScroller.setMaximumSize(new Dimension(200, f.getHeight() * 1000));
JButton button = new JButton("Vali");
button.setActionCommand(Integer.toString(list.getSelectedIndex()));
button.addActionListener(kuular);
Font font = new Font("Arial", Font.PLAIN, 12);
txtala = new JTextArea("<-- Vali sealt");
txtala.setEditable(false);
txtala.setMargin(new Insets(5, 8, 0, 0));
txtala.setFont(font);
scrl = new JScrollPane(txtala, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrl.setPreferredSize(new Dimension(f.getWidth() - 200, f.getHeight() - 20));
pilt.setBackground(Color.PINK);
pilt.setVisible(false);
pilt.setPreferredSize(new Dimension(f.getWidth() - 200, f.getHeight() - 20));
GroupLayout.ParallelGroup menu = layout.createParallelGroup();
GroupLayout.SequentialGroup row = layout.createSequentialGroup();
GroupLayout.SequentialGroup leftright = layout.createSequentialGroup();
GroupLayout.ParallelGroup topdown = layout.createParallelGroup();
GroupLayout.ParallelGroup dbl = layout.createParallelGroup();
GroupLayout.ParallelGroup dblrow = layout.createParallelGroup();
menu.addComponent(kiri);
menu.addComponent(listScroller);
menu.addComponent(button);
leftright.addGroup(menu);
dbl.addComponent(scrl);
dbl.addComponent(pilt);
leftright.addGroup(dbl);
row.addComponent(kiri);
row.addComponent(listScroller);
row.addComponent(button);
topdown.addGroup(row);
dblrow.addComponent(scrl);
dblrow.addComponent(pilt);
topdown.addGroup(dblrow);
layout.setHorizontalGroup(leftright);
layout.setVerticalGroup(topdown);
panel.setComponentZOrder(pilt, 1);
panel.setComponentZOrder(scrl, 0);
f.add(panel);
//f.pack();
f.setVisible(true);
}
public static void praxStarter() throws Exception{
// As a note - nrs is the holder for menu indexes
// info is a Map of those same menu items
// And one entry in info is in the form of String[]{name, class.method}
String[] tekst = new String[2];
String kls, met;
Method meetod;
txtala.setText("");
tekst = info.get(nrs.get(indez));
kls = tekst[1].substring(0, tekst[1].indexOf("."));
met = tekst[1].substring(tekst[1].indexOf(".") + 1, tekst[1].length());
meetod = Class.forName(kls).getMethod(met);
meetod.setAccessible(true);
meetod.invoke(Class.forName(kls).newInstance());
}
此外，以下是一个类（试图）在那里进行绘图的示例：
public class brush extends Applet {
public void paint(Graphics g) {
int x0 = 150;
int y0 = 150;
int r = 100;
int x, y;
double t;
int w = getWidth();
int h = getHeight();
x0 = w / 2;
y0 = h / 2;
g.setColor(Color.white);
g.fillRect(0, 0, w, h);
g.setColor(Color.black);
for (t = -Math.PI; t < Math.PI; t = t + Math.PI / 16) {
x = (int) (r * Math.cos(t) + x0);
y = (int) (r * Math.sin(t) + y0);
g.drawLine(x0, y0, x, y);
}
}
}
非常感谢您提供的答复和建议！
编辑：这里是一张截图：
左侧是普通的在屏幕上打印文本模块。右侧是文本部分已隐藏，并显示了JPanel，该JPanel是从pilt = new JPanel()部分绘制的，但没有进行任何其他成功编辑除了主类以外。
编辑：我尝试了多种绘图方式，尝试了搜索结果中提供的解决方案，例如：
`txtala.setVisible(false);
scrl.setVisible(false);
pilt.setBorder(BorderFactory.createLineBorder(Color.BLACK));
pilt.setVisible(true);
//bi = new BufferedImage(pilt.getWidth() + 1000, pilt.getHeight() + 1000, BufferedImage.TYPE_INT_ARGB);
Graphics g = pilt.getGraphics();
g.setColor(Color.black);
g.drawLine(0, 0, 1000, 1000);
g.drawString("OLOLOLOLO!", 30, 50);
pilt.paint(g);
pilt.update(g);
//g.dispose();
//repaint();`
method.invoke（...）调用的方法应该能够进行绘制吗？ - Denis Washington