![](/img/trans.png)
[英]Trying to mirror a picture with java android canvas.drawImage
[英]Java Canvas drawImage Flashes
我总是在StackOverflow中寻找问题,但是我似乎没有找到答案。
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。
我从数据库中预加载图像,将其绘制到画布中,然后将JFrame设置为可见。
问题是图像将闪烁:显示了几毫秒,然后重新绘制了JFrame。
为什么会这样? 我也尝试覆盖JFrame中的paint()
方法,并在每次调用paint
绘制图像。 但这不是这种方式。
Button Frame
(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
(显示图像的帧)
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
}
影片范例: https : //drive.google.com/file/d/0B53gOV_BD8J8Mm10LW5CN2E3M2M/view
问题已解决:
我已经在JFrame中覆盖了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,因为它已设置为适合JFrame,并且图像未显示。 我已将其删除(AWT画布),并且图像现在显示在背景中。
非常感谢你!
特别感谢Dodd10x和Andrew Thompson。
不要混用Swing和AWT。 要更改的第一件事是,如果要在JFrame中显示,请从Canvas切换到JComponent。
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