我有一个程序可以为JPanel
(JScrollbar
)添加一堆组件。但是,由于它添加了很多组件,因此大多数组件都不适合可见区域(Viewport
)。
当一切都加载并且我开始向下滚动时,我注意到组件在进入Viewport
区域时正在对齐并设置它们的位置。这导致我的JScrollPane
高于必要值。这使得它在我结束时“快速”(组件突然向上移动(正确对齐),视口也是如此)。
我尝试拨打repaint()
和validate()
,但没有任何效果。我做错了什么?
答案 0 :(得分:7)
我建议发布一个SSCCE,以便完全复制您的具体问题。
我做了一个简短的例子,可能会引导你朝着正确的方向前进。
基本上只需将JButton
添加到JPanel
并添加GridLayout
,JScrollPane
依次添加到import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class JScrollPaneOfComponents {
/**
* Default constructor for ScrollBarOfComponents.class
*/
public JScrollPaneOfComponents() {
initComponents();
}
/**
* Initialize GUI and components (including ActionListeners etc)
*/
private void initComponents() {
JFrame jFrame = new JFrame();
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new GridLayout(15, 15));
//create 225 JButtons and add them to JPanel;
for (int i = 0; i < (15*15); i++) {
panel.add(new JButton(String.valueOf((i + 1))) {
//make buttons bigger for demonstartion purposes
@Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
});
}
JScrollPane scrollpane = new JScrollPane(panel) {
//size the JScrollPane purposelfully smaller than all components
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
};
//add scrollpane to frame
jFrame.add(scrollpane);
//pack frame (size JFrame to match preferred sizes of added components and set visible
jFrame.pack();
jFrame.setVisible(true);
}
public static void main(String[] args) {
/**
* Create GUI and components on Event-Dispatch-Thread
*/
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
try {
//set nimbus look and feel
for (UIManager.LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException e) {
e.printStackTrace();
}
//create new instance of GUI
JScrollPaneOfComponents test = new JScrollPaneOfComponents();
}
});
}
}
。
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