JScrollPane具有冻结和可滚动组件的列标题

Question

我有一个JScrollPane，其中包含由多个组件组成的列标题。其中一个组件需要静态定位，而其他组件需要像正常一样滚动。

我能想到做的唯一一件事就是添加一个侦听这台冷冻组件的这样的位置滚动条：

frozenHeader.setLocation(scrollViewport.getVisibleRect().getLocation()). 

但是，位置实际上不会更新，直到滚动条没有长时间滚动，所以它看起来相当不吸引人。是的，我已经尝试在frozenHeader及其父母上拨打revalidate()，然后拨打repaint()。

这里是重现什么我谈论的例子：

import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.GridBagConstraints; 
import java.awt.GridBagLayout; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JScrollPane; 

/** 
* 
* @author brian 
*/ 
public class TestScroll extends JFrame { 
    private JScrollPane scrollPane; 
    private JPanel viewport; 
    private JPanel colHeader; 

    // This should be frozen 
    private JPanel frozenHeader; 
    // This should scroll 
    private JPanel scrollHeader; 

    public TestScroll() { 
     this.setSize(new Dimension(500, 400)); 
     this.setResizable(false); 
     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     // Set up the scroll pane 
     scrollPane = new JScrollPane(); 
     viewport = new JPanel(); 
     viewport.setPreferredSize(new Dimension(1000, 400)); 
     scrollPane.setViewportView(viewport); 

     // Set up the scroll panes column header 
     colHeader = new JPanel(new GridBagLayout()); 
     frozenHeader = new JPanel(); 
     // Width is equal to the frame's width, as it should stay in the same location 
     frozenHeader.setPreferredSize(new Dimension(500, 30)); 
     frozenHeader.setBackground(Color.RED); 

     scrollHeader = new JPanel(); 
     // Width equal to viewportview's as it should scroll 
     scrollHeader.setPreferredSize(new Dimension(1000, 30)); 
     scrollHeader.setBackground(Color.BLUE); 
     JLabel label = new JLabel("Text"); 
     scrollHeader.add(label); 

     GridBagConstraints c = new GridBagConstraints(); 
     c.anchor = GridBagConstraints.WEST; 
     c.gridx = 0; 
     c.gridy = 0; 
     colHeader.add(frozenHeader, c); 
     c.gridy = 1; 
     colHeader.add(scrollHeader, c); 
     scrollPane.setColumnHeaderView(colHeader); 

     add(scrollPane); 
    } 

    public static void main(String args[]) { 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       new TestScroll().setVisible(true); 
      } 
     }); 
    } 
} 

我想frozenHeader（红色面板）始终在屏幕的滚动，而不是关闭屏幕居中，和（蓝色面板）继续滚动，如同在示例中一样。

要多添一点而言，我不是简单地把在视口中，或移动frozenHeader出列标题，并简单地将其置于JScrollPane以上的原因是因为我在实际应用中JScrollPane有上左角面板与列标题高度相同。由于应用程序的性质，我需要利用所有的屏幕空间。

任何有关如何完成这一任务的建议将不胜感激！

Answer 1

“我希望红色面板始终居中在屏幕上，而不是滚动屏幕。”

问题是你正在设置columnHeaderView。这很容易实现，但只是设置添加colHeader面板作为独立的实体，与不设置columnHeaderView

colHeader = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 0)); 
    colHeader.add(frozenHeader); 
    JPanel panelForScrollPaneAndScrollHeader = new JPanel(new BorderLayout()); 
    panelForScrollPaneAndScrollHeader.add(scrollHeader, BorderLayout.NORTH); 
    panelForScrollPaneAndScrollHeader.add(scrollPane, BorderLayout.CENTER); 

    add(colHeader, BorderLayout.NORTH); 
    add(panelForScrollPaneAndScrollHeader, BorderLayout.CENTER); 

这里是这样做的

import java.awt.BorderLayout; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.FlowLayout; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JScrollPane; 

public class TestScroll1 extends JFrame{ 
    private JScrollPane scrollPane; 
    private JPanel viewport; 
    private JPanel colHeader; 
    private JPanel frozenHeader; 
    private JPanel scrollHeader; 

    public TestScroll1() { 
     frozenHeader = new JPanel(); 
     frozenHeader.setPreferredSize(new Dimension(500, 30)); 
     frozenHeader.setBackground(Color.RED); 

     scrollHeader = new JPanel(); 
     scrollHeader.setPreferredSize(new Dimension(1000, 30)); 
     scrollHeader.setBackground(Color.BLUE); 

     scrollPane = new JScrollPane(); 
     viewport = new JPanel(); 
     viewport.setPreferredSize(new Dimension(1000, 400)); 
     scrollPane.setViewportView(viewport); 


     colHeader = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 0)); 
     colHeader.add(frozenHeader); 
     JPanel panelForScrollPaneAndScrollHeader = new JPanel(new BorderLayout()); 
     panelForScrollPaneAndScrollHeader.add(scrollHeader, BorderLayout.NORTH); 
     panelForScrollPaneAndScrollHeader.add(scrollPane, BorderLayout.CENTER); 
     add(colHeader, BorderLayout.NORTH); 
     add(panelForScrollPaneAndScrollHeader, BorderLayout.CENTER); 


     setSize(new Dimension(500, 400)); 
     setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     setLocationRelativeTo(null); 

    } 

    public static void main(String args[]) { 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       new TestScroll1().setVisible(true); 
      } 
     }); 
    } 
}