import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class CirclePanel extends JPanel {
private JTextField xField, yField, diameterField;
private JButton Redraw;
private JLabel xLabel, yLabel, rLabel;
Circle myCircle = new Circle (150, 150, 30, Color.red, Color.white);
Graphics g;
//Paint objects on panel
public void paintComponent (Graphics page) {
super.paintComponent(page);
g = page;
myCircle.draw(g);
}
public CirclePanel(){
xLabel = new JLabel("X= ");
yLabel = new JLabel("Y= ");
rLabel = new JLabel("R= ");
xField = new JTextField(5);
xField.addActionListener(new TempListener());
yField = new JTextField(5);
yField.addActionListener(new TempListener());
diameterField = new JTextField(5);
diameterField.addActionListener(new TempListener());
Redraw = new JButton("Redraw!");
Redraw.addActionListener(new ButtonListener());
add(xLabel);
add(xField);
add(yLabel);
add(yField);
add(rLabel);
add(diameterField);
add(Redraw);
setPreferredSize(new Dimension(500, 500));
setBackground(Color.white);
}
private class ButtonListener implements ActionListener{
public void actionPerformed (ActionEvent event) {
//Update page
myCircle.draw(g);
//repaint panel
repaint();
}
private class TempListener implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
int x, y, newbase, newhei;
String text = xField.getText();
String text2 = yField.getText();
x = Integer.parseInt (text);
y = Integer.parseInt (text2);
myCircle.draw(g);
repaint();
}
}
}
}
大家好我想创建绘制圆形的Java应用程序并使用JTextField中的新值重绘它。我为它写了三节课。其中一个包含accessor,mutators,constructor。其中一个课程当然有主要方法,其中一个课程在上面。但TempListener无法正常工作。你能救我吗?
答案 0 :(得分:1)
您应该从程序中获取图形字段g。而是使用本地Graphics变量,即在paintComponent方法中调用page
的变量,但不要在其他任何地方使用它。
建议:
repaint()
。myCircle.draw(g);
,因为它不属于那里。