我总是在 StackOverflow 中寻找问题,但我似乎找不到这个问题的答案。
我正在使用 Java 创建带有 Swing 表单的应用程序。我已将 Canvas AWT 组件添加到 JFrame。
我从数据库预加载图像,将其绘制到 Canvas 中,然后将 JFrame 设置为可见。
问题是图像会闪烁:它显示几毫秒,然后重新绘制 JFrame。
为什么会发生这种情况?我也尝试重写 JFrame 中的 paint()
方法,并在每次调用 paint
时绘制图像。但事实并非如此。
按钮框架
(主框架)-(将final String imgPath
替换为您选择的示例图像)
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ButtonFrame extends javax.swing.JFrame {
public ButtonFrame() {
initComponents();
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("View Image");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(59, 59, 59)
.addComponent(jButton1)
.addContainerGap(44, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(54, 54, 54)
.addComponent(jButton1)
.addContainerGap(70, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
final String imgPath = "/tmp/img.png";
try
{
BufferedImage bi = ImageIO.read(new File(imgPath));
ImgFrame imgFrame = new ImgFrame();
imgFrame.setImage(bi);
imgFrame.setVisible(true);
// imgFrame.setImageInCanvas(bi);
} catch (IOException x) {}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
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(ButtonFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ButtonFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ButtonFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ButtonFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new ButtonFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
// End of variables declaration
}
ImageFrame
(显示图像的框架)
import java.awt.Graphics;
import java.awt.image.BufferedImage;
public class ImgFrame extends javax.swing.JFrame {
BufferedImage bi;
public ImgFrame() {
initComponents();
}
public void setImage(BufferedImage bi)
{
this.bi = bi;
}
public void setImageInCanvas(BufferedImage bi)
{
canvas1.getGraphics().drawImage(bi, 0, 0, null);
}
@Override
public void paint(Graphics g)
{
setImageInCanvas(bi);
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
canvas1 = new java.awt.Canvas();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(canvas1, javax.swing.GroupLayout.PREFERRED_SIZE, 266, javax.swing.GroupLayout.PREFERRED_SIZE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(canvas1, javax.swing.GroupLayout.PREFERRED_SIZE, 155, javax.swing.GroupLayout.PREFERRED_SIZE)
);
pack();
}// </editor-fold>
// Variables declaration - do not modify
private java.awt.Canvas canvas1;
// End of variables declaration
}
视频示例: https://drive.google.com/file/d/0B53gOV_BD8J8Mm10LW5CN2E3M2M/view
<小时/>问题已解决:
我已经重写了 JFrame 中的 paint
方法,如下所示:
@Override
public void paint(Graphics g)
{
g.drawImage(bi, 0, 0, null);
}
其中 bi
是 BufferedImage。
然后,Canvas 与 Form 重叠,因为它被设置为适合 JFrame,并且图像未显示。我已将其删除(AWT Canvas ),图像现在显示在背景中。
非常感谢!
特别感谢 Dodd10x 和 Andrew Thompson。
最佳答案
不要混合使用 Swing 和 AWT。如果您在 JFrame 中显示,首先要更改的是从 Canvas 切换到 JComponent。
关于Java Canvas绘制图像闪烁,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33086903/