我非常需要你的帮助,因为我无法独自解决这个问题。我正在尝试创建一个 GUI,并希望在按下按钮后在其中绘制一些内容,但我似乎有某种刷新/重新验证或线程问题。画了,但是当我调整窗口大小时,画就消失了。此外,当非常快速地移动窗口时,绘图的某些部分会消失。我尝试了很多方法,但我无法解决这个问题,也许你可以帮助我。我被指示不要一开始就编写自己的代码,而是使用 NetBeans Design 函数来生成按钮和面板等。也许这会损害绘图过程/功能,但我不知道。我会发布相关的代码,非常感谢你的建议(被注释的东西只是我以前尝试过的人工制品,所以不要介意):
public class NewJFrame extends JFrame {
public NewJFrame() { initComponents(); }
@SuppressWarnings("unchecked")
private void initComponents() {
jButton1 = new javax.swing.JButton();
jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setMinimumSize(new java.awt.Dimension(1200, 1000));
jButton1.setText("Draw");
jButton1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
GroupLayout jPanel1Layout = new GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addGap(0, 1000, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addGap(0, 0, Short.MAX_VALUE)
);
GroupLayout layout = new GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, GroupLayout.DEFAULT_SIZE, 1000, Short.MAX_VALUE)
.addGap(18, 18, 18)
.addComponent(jButton1)
.addGap(33, 33, 33))
);
layout.setVerticalGroup(
layout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(0, 745, Short.MAX_VALUE)
.addComponent(jButton1)
.addGap(237, 237, 237))
.addGroup(layout.createSequentialGroup()
.addComponent(jPanel1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addContainerGap())))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(ActionEvent evt) {
Graphics g = jPanel1.getGraphics();
draw(jPanel1, g);
}
protected void paintComponent(Graphics g){
jPanel1.setSize(1000, 1000);
Dimension d = jPanel1.getSize();
g.setColor(Color.BLACK);
for (int i=0; i<=1000;i++){
if (i%100==0){
g.setColor(Color.RED);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
else if(i%50==0 && i%100!=0){
g.setColor(Color.BLUE);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
else {
g.setColor(Color.BLACK);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
}
g.setColor(Color.green);
g.drawLine(0, d.height / 2, d.width, d.height / 2);
}
public void draw(JPanel Jpanel1, Graphics g) {
System.out.println("wuffkowski");
Jpanel1.setSize(1000,1000);
Dimension d = Jpanel1.getSize();
g.setColor(Color.BLACK);
for (int i=0; i<=1000;i++){
if (i%100==0){
g.setColor(Color.RED);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
else if(i%50==0 && i%100!=0){
g.setColor(Color.BLUE);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
else {
g.setColor(Color.BLACK);
g.drawLine(i, d.height/2, i, (d.height/2)+100);
}
}
g.setColor(Color.green);
g.drawLine(0, d.height / 2, d.width, d.height / 2);
Jpanel1.paintComponents(g);
}
public static void lala () {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
NewJFrame JF =new NewJFrame();
JF.setVisible(true);
}
});
}
private javax.swing.JButton jButton1;
private javax.swing.JPanel jPanel1;
}
再次感谢您的宝贵时间。
Java 不记得为你绘制的命令;当你单击按钮时,你的图形会呈现一次,因为这是调用draw()
的唯一一次。
如果要在调整大小后刷新渲染,请覆盖paint(Graphics)
并调用其中的draw()
。
如果这与按钮单击有关,则必须向类中添加字段,在其中记住draw()
所需的所有内容,包括它是否应该绘制任何内容:
private boolean drawAtAll = false;
private void jButton1ActionPerformed(ActionEvent evt) {
drawAtAll = true; // ok to draw now
draw();
}
@Override
public void paint(Graphics g) {
super.paint(g);
draw();
}
public void draw() {
if( !drawAtAll ) return;
Graphics g = jPanel1.getGraphics();
...
}
延伸阅读:
- 课程:执行自定义绘画
- 在AWT和Swing中绘画
尝试使用此代码,并提出可能出现的任何问题,在 JPanel 的 paintComponent(...) 方法中进行绘画。与其每次都为所述JComponent
提供大小,不如简单地覆盖所述组件的 getPreferredSize()。为了调用您的paintComponent(...)
您可以简单地编写repaint()
,而不是从程序中显式调用paintComponent(...)
,Swing 将自动执行此操作。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class PaintingExample
{
private CustomPanel paintingPanel;
private Timer timer;
private int x = 1;
private int y = 1;
private ActionListener timerAction = new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
x++;
y++;
paintingPanel.setPosition(x, y);
}
};
private void createAndDisplayGUI()
{
JFrame frame = new JFrame("Painting Example");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
paintingPanel = new CustomPanel();
final JButton startStopButton = new JButton("STOP");
startStopButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent ae)
{
if (timer.isRunning())
{
startStopButton.setText("START");
timer.stop();
}
else if (!timer.isRunning())
{
startStopButton.setText("STOP");
timer.start();
}
}
});
frame.add(paintingPanel, BorderLayout.CENTER);
frame.add(startStopButton, BorderLayout.PAGE_END);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
timer = new Timer(100, timerAction);
timer.start();
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new PaintingExample().createAndDisplayGUI();
}
});
}
}
class CustomPanel extends JPanel
{
private int x = 0;
private int y = 0;
@Override
public Dimension getPreferredSize()
{
return (new Dimension(800, 600));
}
public void setPosition(int a, int b)
{
x = a;
y = b;
if (x <(getWidth() - 10) && y < (getHeight() - 10))
repaint();
else
System.out.println("Nothing is happening...");
}
@Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.clearRect(0, 0, getWidth(), getHeight());
g.setColor(Color.MAGENTA);
g.fillOval(x, y, 10, 10);
}
}
浏览您的所有代码,但是立即可见的是,您不应该在不调用super.paintComponent
的情况下覆盖paintComponent
方法。你注释掉的线路调用super.paintComponents
(注意 s),这是不一样的。
我也不确定你的意思是"当我调整窗口大小时",以及它如何与出现在代码中的Jpanel1.setSize( 1000, 1000 )
调用联系在一起。您的布局管理器将负责面板的大小。不应将其设置为固定大小。
当您调整面板大小或更改其位置或最小化并最大化面板时,将调用重新绘制内容的 paint(...)
方法。你必须覆盖这个函数,让它画你的线或其他什么。为此,您可能必须将图形保存在数据结构中,以便能够在必要时重新绘制它。
此处描述了绘制方法。