我可以分頁JList

Question

有沒有辦法在JList中分頁結果，我有100個結果顯示，我只想顯示20每次..我想用表來顯示我的結果，但我顯示推文，所以它是一個JPanel，它具有圖像和文本..等等，所以它的一個JList

Answer 1

看看這個link顯示一個分頁jlist。

這裏是類：

/** 
* A paginated list. Only displays a specific number of rows 
* and allows you to page backwards and forwards through the list 
* with the help of a toolbar. 
*/ 
public class PaginatedList extends JPanel { 

    private final int pageSize; 
    private final JList list; 
    private final ListModel model; 

    private final int lastPageNum; 
    private int currPageNum;  
    private JLabel countLabel ; 
    private JButton first, prev, next, last; 

    /** 
    * @param list the jlist 
    * @param pageSize the number of rows visible in the jlist 
    */ 
    public PaginatedList(JList list, int pageSize) { 
     super(); 
     this.pageSize = pageSize; 
     this.list = list; 
     this.model = list.getModel(); 

     //work out how many pages there are 
     this.lastPageNum = model.getSize()/pageSize + (model.getSize() % pageSize != 0 ? 1 : 0); 
     this.currPageNum = 1; 

     setLayout(new BorderLayout()); 
     countLabel = new JLabel() ; 
     add(countLabel, BorderLayout.NORTH); 
     add(list, BorderLayout.CENTER); 
     add(createControls(), BorderLayout.SOUTH); 
     updatePage(); 
    } 

    private JPanel createControls() { 
     first = new JButton(new AbstractAction("<<") { 
      public void actionPerformed(ActionEvent e) { 
       currPageNum = 1; 
       updatePage(); 
      } 
     }); 

     prev = new JButton(new AbstractAction("<") { 
      public void actionPerformed(ActionEvent e) { 
       if (--currPageNum <= 0) 
        currPageNum = 1;     
       updatePage(); 
      } 
     }); 

     next = new JButton(new AbstractAction(">") { 
      public void actionPerformed(ActionEvent e) { 
       if (++currPageNum > lastPageNum) 
        currPageNum = lastPageNum; 
       updatePage(); 

      } 
     }); 

     last = new JButton(new AbstractAction(">>") { 
      public void actionPerformed(ActionEvent e) { 
       currPageNum = lastPageNum; 
       updatePage(); 
      } 
     }); 

     JPanel bar = new JPanel(new GridLayout(1, 4)); 
     bar.add(first); 
     bar.add(prev); 
     bar.add(next); 
     bar.add(last); 
     return bar; 
    } 

    private void updatePage() { 

     //replace the list's model with a new model containing 
     //only the entries in the current page. 
     final DefaultListModel page = new DefaultListModel(); 
     final int start = (currPageNum - 1) * pageSize; 
     int end = start + pageSize; 
     if (end >= model.getSize()) { 
      end = model.getSize(); 
     } 
     for (int i = start; i < end; i++) { 
      page.addElement(model.getElementAt(i)); 
     } 
     list.setModel(page); 

     //update the label 
     countLabel.setText("Page " + currPageNum + "/" + lastPageNum); 

     // update buttons 
     final boolean canGoBack = currPageNum != 1; 
     final boolean canGoFwd = currPageNum != lastPageNum; 
     first.setEnabled(canGoBack); 
     prev.setEnabled(canGoBack); 
     next.setEnabled(canGoFwd); 
     last.setEnabled(canGoFwd); 
    }  
} 

用法示例：

public static void main(String args[]) throws Exception { 

    // create 100 elements of dummy data. 
    Integer[] data = new Integer[100]; 
    for (int i = 0; i < data.length; i++) { 
     data[i] = i + 1; 
    } 

    // create a paginated list with page size 20 
    PaginatedList list = new PaginatedList(new JList(data), 20); 

    // add it to a frame 
    JFrame f = new JFrame(); 
    f.add(list); 
    f.setSize(100, 100); 
    f.pack(); 
    f.setVisible(true); 
}