Java 重新绘制另一个JPanel中的JPanel
事情是这样的:Java 重新绘制另一个JPanel中的JPanel,java,swing,jpanel,Java,Swing,Jpanel,事情是这样的: public class ParentPanel extends JPanel{ private ChildPanel childPanel; public ParentPanel() { super(); initComponents(); } public void pushData(int data){ childPanel.pushData(data); } private v
public class ParentPanel extends JPanel{
private ChildPanel childPanel;
public ParentPanel() {
super();
initComponents();
}
public void pushData(int data){
childPanel.pushData(data);
}
private void initComponents() {
childPanel= new ChildPanel();
}
我还有一门课:
public class ChildPanel extends JPanel{
public ChildPanel(){
super();
}
public void paintComponent(Graphics g){
//I draw some lines in this JPanel according to data
}
public void pushData(int data){
repaint();
}
}
我想要的是在调用ChildPanel中的
pushData()
方法时画一些线。但是现在在ChildPanel中没有响应。我该怎么办?childPanel
不是任何容器的一部分,它的paintComponent
不会被调用。尝试将其作为子级添加到ParentPanel
,即在initComponents
调用add(childPanel)
中
编辑:基于已发布代码的示例
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TestChild {
public static void main(String[] args){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final ParentPanel parent = new ParentPanel();
JButton button = new JButton("Push");
button.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
parent.pushData(7);
}
});
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
panel.add(parent, BorderLayout.CENTER);
panel.add(button, BorderLayout.SOUTH);
frame.add(panel);
frame.pack();
frame.setVisible(true);
frame.setLocationRelativeTo(null);
}
public static class ParentPanel extends JPanel {
private ChildPanel childPanel;
public ParentPanel() {
super();
initComponents();
}
public void pushData(int data) {
childPanel.pushData(data);
}
private void initComponents() {
childPanel = new ChildPanel();
add(childPanel);
}
}
public static class ChildPanel extends JPanel {
private Random random = new Random();
public ChildPanel() {
super();
setPreferredSize(new Dimension(200, 200));
}
@Override
public void paintComponent(Graphics g) {
System.out.println(getWidth());
g.setColor(getBackground());
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor(Color.getHSBColor(random.nextFloat(), 0.9f, 1.0f));
g.fillOval(0, 0, getWidth(), getHeight());
}
public void pushData(int data) {
repaint();
}
}
}
很抱歉,我刚才遗漏了initComponents()内部的代码,实际上initComponents()内部的代码是由netBeansAlso生成的,在类ChildPanel()的pushData()方法中,我调用了repaint()。这会调用paintComponent()?@缓存您看不到绘制的结果,或者您确定
paintComponent
未被调用。我包含了一个基于发布代码的示例,看看这是否对您有帮助。AFAIK,repaint()
调用paint(…)
,inturns调用paintComponent()/paintBorder()/我忘记了最后一个方法的名称
:(