我有一个程序,可以将一堆组件添加到JPanel
(在JScrollbar
中)。但是,由于它添加了如此多的组件,其中大多数组件都不适合可见区域(Viewport
)。
当所有内容加载并开始向下滚动时,我注意到组件在进入 Viewport
区域时正在对齐并设置其位置。这导致我的 JScrollPane
高于必要的值。当我到达末尾时,这使得它“突然”移动(组件突然向上移动(正确对齐),视口(viewport)也是如此)。
我尝试调用repaint()
和validate()
,但没有任何效果。我做错了什么?
最佳答案
我建议发布SSCCE为了准确地复制您的具体问题。
我做了一个简短的例子,可能会引导您走向正确的方向。
基本上只会使用 GridLayout
将 225 个 JButton
添加到 JPanel
,而 GridLayout
又会添加到 JScrollPane
。
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();
}
});
}
}
关于java - 将组件粘贴到 JScrollPane 上,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13237678/