如何覆蓋paintComponent方法並響應狀態變化? 錯誤消息:空隙是一個無效的類型可變的paintComponent狀態變化時在paintComponent()上調用@Override
public class MyContainer extends Container {
public void paintComponent(Graphics m){
m.drawArc(100,100,100,100,100,100);
m.setColor(Color.green);
m.fillArc(100,100,100,100,100,100);
}
public static void main(String[] args){
Container y = new Container();
JFrame x = new JFrame();
JPanel gg = new JPanel();
x.add(y);
x.setTitle(" Shape Changer");
x.setBounds(100,50,500,300);
x.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
x.getContentPane().add(new ContentPanel());
x.getContentPane().add(new ContnetPanel());
x.setContentPane(new ContnetPanel());
x.setVisible(true);
}
static class ContentPanel extends JPanel{
private Graphics g;
private JPanel ss;
public void paint(Graphics g){
g.drawArc(100,100,100,100,100,100);
g.fillRect(100, 100,100,100);
}
public ContentPanel(){
}
}
static class ContnetPanel extends JPanel implements ActionListener, ChangeListener{
JComboBox comboerbox;
class appres {
public void paint(Graphics h){
h.drawRect(100,100,100,100);
h.setColor(Color.red);
h.fillRect(100,100,100,100);
}
}
public ContnetPanel(){
comboerbox = new JComboBox();
comboerbox.addItem("Red Square");
comboerbox.addItem("Blue Square");
comboerbox.addItem("Green Square");
comboerbox.setSelectedIndex(1);
add(comboerbox);
setLayout(new GridLayout(2,1));
}
@Override
protected void paintComponent(Graphics h){
super.paintComponent(h);
h.drawArc(100,100,100,100,100,100);
h.setColor(Color.blue);
h.fillArc(100,100,100,100,100,100);
repaint();
}
int yy = 0;
public void actionPerformed(ActionEvent evt){
switch(comboerbox.getSelectedIndex()){
case 0:yy=0;
case 1: yy=1;
case 2: yy=2;
}
}
//evt.getSource()==comboerbox
public void stateChanged(ChangeEvent evt){
if(evt.getSource()==comboerbox){
@Override
protected void paintComponent(Graphics h){
super.paintComponent(h);
h.drawArc(100,100,100,100,100,100);
h.setColor(Color.blue);
h.fillArc(100,100,100,100,100,100);
repaint();
}
}
else
{
System.out.println("DONE");
}
}
}
}
當然,方法的paintComponent不是變量。我如何重寫paintComponent在這裏?或者更好的方式來響應狀態改變來改變形狀?那太棒了! 提前致謝,愛你們!