用Java创建一个漂亮的listview

我是JavaSwing新手，我正在尝试创建一个显示目录内容的列表视图。我希望创建一个类似下图的视图：

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我知道如何使用JList，但我不知道如何显示与文件类型匹配的图标。如您所见，从图像中，我们可以直观地区分pdf文件、文本文件和其他文件。我应该尝试使用JList还是其他UI组件？

我也做过类似的事情；下面是我的输出示例

我为树使用了自定义渲染器；它生成缩进、图标和文本，您可以在显示器最左侧列的一个单元格中看到这些内容。以下是这方面的来源：

package spacecheck.ui.renderer;

import java.awt.Component;

import javax.swing.ImageIcon;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;

import spacecheck.filedata.FileCollection;
import spacecheck.images.TreeIcon;

/**
 * renders the name of a collection for the tree display.
 * @author rcook
 *
 */
public class CollectionNameRenderer extends DefaultTableCellRenderer // which implements JLabel
//    implements TableCellRenderer
{
  private static final long serialVersionUID = 1L;
  @SuppressWarnings({"unused"})
  private void say(String msg) { System.out.println(msg); }

  private static TreeIcon tIcon = null;

  /**
   * set the value of the CollectionName for the JTable; includes using
   * indent so that the correct icon can be obtained (icons are different widths
   * to implement different indent levels).
   */
  public void setValue(Object value)
  {
    FileCollection fc = (FileCollection)value;
    boolean expanded = fc.isExpanded();
    int level = fc.getDisplayLevel();
//    boolean isSelected = table.
    ImageIcon icon = tIcon.getIcon(level, expanded);
    if (icon != null) { setIcon(icon); }
    setText(value.toString());
  }

  /**
   * get the renderer component for a collection name.
   */
  public Component getTableCellRendererComponent
      (JTable table, Object value, boolean isSelected, boolean hasFocus, 
          int rowIndex, int colIndex)
  {
    if (tIcon == null) { tIcon = new TreeIcon(table.getBackground()); }
    return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, rowIndex, colIndex);
  }
}

该类使用我的另一个名为TreeIcon的类；它实现如图所示的文件夹图标缩进，以及根据文件夹的展开/未展开状态选择图标。这是一节课：

package spacecheck.images;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * represents an icon used in the directory tree; handles 'expanded' and
 * 'unexpanded' directories as well as indentation representing different
 * levels.
 * @author rcook
 *
 */
public class TreeIcon
{
  public static int UNEXPANDED = 1;
  public static int EXPANDED = 2;

  @SuppressWarnings({"unused"})
  private void say (String msg) { System.out.println(msg); }

  private static ImageIcon expandedIcon = null;
  private static ImageIcon unexpandedIcon = null;
  private static int       iconHeight = 0;
  private static int       iconWidth  = 0;

  private static ArrayList<ImageIcon> cachedExpandedIcons = new ArrayList<ImageIcon>();
  private static ArrayList<ImageIcon> cachedUnexpandedIcons = new ArrayList<ImageIcon>();

  static
  {
    expandedIcon = new ImageIcon(TreeIcon.class.getResource("images/Expanded.png"));
    unexpandedIcon = new ImageIcon(TreeIcon.class.getResource("images/Unexpanded.png"));
    iconHeight = unexpandedIcon.getIconHeight();
    iconWidth =  unexpandedIcon.getIconWidth();
  }

  public TreeIcon(Color givenColor)  {  }

  public static void main(String ... arguments)
  {
    JFrame frame = new JFrame("icon test");
    JLabel label = new JLabel("background test");
    label.setBackground(Color.blue);
    TreeIcon treeIcon = new TreeIcon(Color.black);
    ImageIcon icon = treeIcon.getIcon(2, false);
    label.setIcon(icon);
    frame.add(label);
    frame.pack();
    frame.setVisible(true);
  }

  /**
   * return the icon for an expanded or unexpanded level
   * @param int level of folder relative to other levels displayed;
   * starts at 0 and increases with depth
   * @param boolean indicates whether this level is expanded or not.
   * @return ImageIcon appropriate for expansion flag and level.
   */
  public ImageIcon getIcon(int level, boolean expanded)
  {
    ImageIcon result = null;

    if (level < 0)
    { System.out.println("level is " + level + ", setting to 0");
      level = 0;
    }

    // set our list of icons depending on whether we are expanded.
    ArrayList<ImageIcon> cachedIcons = cachedUnexpandedIcons;
    if (expanded) { cachedIcons = cachedExpandedIcons; }

    // if we already have this icon in our cache, return it.
    if (cachedIcons.size() >= (level+1) && cachedIcons.get(level) != null)
    {
      result = cachedIcons.get(level);
    }
    else
    {
      // generate this icon and store it in the cache before returning it.
      ImageIcon baseIcon = unexpandedIcon;
      if (expanded) { baseIcon = expandedIcon; }
      int iconH = iconHeight;
      int iconW = iconWidth*(level+1);

      BufferedImage bufferedImage = new BufferedImage(iconW,iconH,BufferedImage.TYPE_INT_ARGB);
      Graphics g = bufferedImage.getGraphics();

      g.drawImage(baseIcon.getImage(), iconWidth*level, 0, null);

      result = new ImageIcon(bufferedImage);

      // we've created an icon that was not in the cached list; 
      // the cached list may have a null at this slot, or it may not yet be
      // long enough to have this slot.  Ensure that we have enough slots
      // in the list, and then add this icon.
      for (int i=cachedIcons.size(); i<=level; i++)
      {
        cachedIcons.add(null);
      }
//      if (cachedIcons.size() < level + 1) { cachedIcons.add(result); }
//                                     else { 
      cachedIcons.set(level, result); 
//      }
//      say("adding icon, level = " + level + (expanded ? " " : " un") + "expanded, width = " + iconW);
    }

    return result;
  }
}

package spacecheck.images；
导入java.awt.Color；
导入java.awt.Graphics；
导入java.awt.image.buffereImage；
导入java.util.ArrayList；
导入javax.swing.ImageIcon；
导入javax.swing.JFrame；
导入javax.swing.JLabel；
导入javax.swing.JPanel；
/**
*表示目录树中使用的图标；处理“扩展”和
*“未展开”目录以及表示不同
*水平。
*@author-rcook
*
*/
公共类树
{
未展开的公共静态int=1；
公共静态int=2；
@SuppressWarnings（{“未使用”}）
私有void say（String msg）{System.out.println（msg）；}
私有静态图像图标expandedIcon=null；
私有静态ImageIcon unexpandedIcon=null；
私有静态int-iconHeight=0；
私有静态int-iconWidth=0；
私有静态ArrayList CacheDexPandeDictions=new ArrayList（）；
私有静态ArrayList cachedUnexpandedIcons=新ArrayList（）；
静止的
{
expandedIcon=newImageIcon（TreeIcon.class.getResource（“images/Expanded.png”）；
unexpandedIcon=newImageIcon（TreeIcon.class.getResource（“images/Unexpanded.png”）；
iconHeight=unexpandedIcon.getIconHeight（）；
iconWidth=unexpandedIcon.getIconWidth（）；
}
公共树（颜色给定颜色）{}
公共静态void main（字符串…参数）
{
JFrame=新JFrame（“图标测试”）；
JLabel标签=新的JLabel（“背景测试”）；
标签.背景（颜色.蓝色）；
TreeIcon TreeIcon=新的TreeIcon（颜色为黑色）；
ImageIcon icon=treeIcon.getIcon（2，false）；
label.setIcon（图标）；
框架。添加（标签）；
frame.pack（）；
frame.setVisible（true）；
}
/**
*返回展开或未展开级别的图标
*@param int相对于显示的其他级别的文件夹级别；
*从0开始，随深度增加而增加
*@param boolean表示是否扩展此级别。
*@return ImageIcon适用于扩展标志和级别。
*/
公共图像图标getIcon（整数级，布尔扩展）
{
ImageIcon结果=空；
如果（级别<0）
{System.out.println（“级别为“+level+”，设置为0”）；
级别=0；
}
//根据是否展开设置图标列表。
ArrayList CacheDictions=CacheDuneExpandedicons；
如果（扩展）{cachedIcons=cachedExpandedIcons；}
//如果缓存中已经有此图标，请将其返回。
if（cachedIcons.size（）>=（级别+1）和&cachedIcons.get（级别）！=null）
{
结果=cachedIcons.get（级别）；
}
其他的
{
//生成此图标并在返回之前将其存储在缓存中。
ImageIcon baseIcon=未扩展指令；
如果（已展开）{baseIcon=expandedIcon；}
int iconH=iconHeight；
int iconW=iconWidth*（级别+1）；
BuffereImage BuffereImage=新的BuffereImage（iconW、iconH、BuffereImage.TYPE_INT_ARGB）；
Graphics g=buffereImage.getGraphics（）；
g、 drawImage（baseIcon.getImage（），iconWidth*级别，0，null）；
结果=新图像图标（BuffereImage）；
//我们创建了一个不在缓存列表中的图标；
//缓存列表在此插槽处可能有一个空值，或者可能还没有空值
//足够长，可以使用此插槽。请确保我们有足够的插槽
//在列表中，然后添加此图标。
对于（int i=cachedIcons.size（）；i我做了类似的事情；下面是我的输出示例


我为树使用了自定义渲染器；它生成缩进、图标和文本，您可以在显示最左侧列的一个单元格中看到这些内容。以下是相关的源代码：

package spacecheck.ui.renderer;

import java.awt.Component;

import javax.swing.ImageIcon;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;

import spacecheck.filedata.FileCollection;
import spacecheck.images.TreeIcon;

/**
 * renders the name of a collection for the tree display.
 * @author rcook
 *
 */
public class CollectionNameRenderer extends DefaultTableCellRenderer // which implements JLabel
//    implements TableCellRenderer
{
  private static final long serialVersionUID = 1L;
  @SuppressWarnings({"unused"})
  private void say(String msg) { System.out.println(msg); }

  private static TreeIcon tIcon = null;

  /**
   * set the value of the CollectionName for the JTable; includes using
   * indent so that the correct icon can be obtained (icons are different widths
   * to implement different indent levels).
   */
  public void setValue(Object value)
  {
    FileCollection fc = (FileCollection)value;
    boolean expanded = fc.isExpanded();
    int level = fc.getDisplayLevel();
//    boolean isSelected = table.
    ImageIcon icon = tIcon.getIcon(level, expanded);
    if (icon != null) { setIcon(icon); }
    setText(value.toString());
  }

  /**
   * get the renderer component for a collection name.
   */
  public Component getTableCellRendererComponent
      (JTable table, Object value, boolean isSelected, boolean hasFocus, 
          int rowIndex, int colIndex)
  {
    if (tIcon == null) { tIcon = new TreeIcon(table.getBackground()); }
    return super.getTableCellRendererComponent(table, value, isSelected, hasFocus, rowIndex, colIndex);
  }
}

该类使用我的另一个名为TreeIcon的类；它实现如图所示的文件夹图标缩进，并根据文件夹的展开/未展开状态选择图标。该类如下：

package spacecheck.images;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.ArrayList;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * represents an icon used in the directory tree; handles 'expanded' and
 * 'unexpanded' directories as well as indentation representing different
 * levels.
 * @author rcook
 *
 */
public class TreeIcon
{
  public static int UNEXPANDED = 1;
  public static int EXPANDED = 2;

  @SuppressWarnings({"unused"})
  private void say (String msg) { System.out.println(msg); }

  private static ImageIcon expandedIcon = null;
  private static ImageIcon unexpandedIcon = null;
  private static int       iconHeight = 0;
  private static int       iconWidth  = 0;

  private static ArrayList<ImageIcon> cachedExpandedIcons = new ArrayList<ImageIcon>();
  private static ArrayList<ImageIcon> cachedUnexpandedIcons = new ArrayList<ImageIcon>();

  static
  {
    expandedIcon = new ImageIcon(TreeIcon.class.getResource("images/Expanded.png"));
    unexpandedIcon = new ImageIcon(TreeIcon.class.getResource("images/Unexpanded.png"));
    iconHeight = unexpandedIcon.getIconHeight();
    iconWidth =  unexpandedIcon.getIconWidth();
  }

  public TreeIcon(Color givenColor)  {  }

  public static void main(String ... arguments)
  {
    JFrame frame = new JFrame("icon test");
    JLabel label = new JLabel("background test");
    label.setBackground(Color.blue);
    TreeIcon treeIcon = new TreeIcon(Color.black);
    ImageIcon icon = treeIcon.getIcon(2, false);
    label.setIcon(icon);
    frame.add(label);
    frame.pack();
    frame.setVisible(true);
  }

  /**
   * return the icon for an expanded or unexpanded level
   * @param int level of folder relative to other levels displayed;
   * starts at 0 and increases with depth
   * @param boolean indicates whether this level is expanded or not.
   * @return ImageIcon appropriate for expansion flag and level.
   */
  public ImageIcon getIcon(int level, boolean expanded)
  {
    ImageIcon result = null;

    if (level < 0)
    { System.out.println("level is " + level + ", setting to 0");
      level = 0;
    }

    // set our list of icons depending on whether we are expanded.
    ArrayList<ImageIcon> cachedIcons = cachedUnexpandedIcons;
    if (expanded) { cachedIcons = cachedExpandedIcons; }

    // if we already have this icon in our cache, return it.
    if (cachedIcons.size() >= (level+1) && cachedIcons.get(level) != null)
    {
      result = cachedIcons.get(level);
    }
    else
    {
      // generate this icon and store it in the cache before returning it.
      ImageIcon baseIcon = unexpandedIcon;
      if (expanded) { baseIcon = expandedIcon; }
      int iconH = iconHeight;
      int iconW = iconWidth*(level+1);

      BufferedImage bufferedImage = new BufferedImage(iconW,iconH,BufferedImage.TYPE_INT_ARGB);
      Graphics g = bufferedImage.getGraphics();

      g.drawImage(baseIcon.getImage(), iconWidth*level, 0, null);

      result = new ImageIcon(bufferedImage);

      // we've created an icon that was not in the cached list; 
      // the cached list may have a null at this slot, or it may not yet be
      // long enough to have this slot.  Ensure that we have enough slots
      // in the list, and then add this icon.
      for (int i=cachedIcons.size(); i<=level; i++)
      {
        cachedIcons.add(null);
      }
//      if (cachedIcons.size() < level + 1) { cachedIcons.add(result); }
//                                     else { 
      cachedIcons.set(level, result); 
//      }
//      say("adding icon, level = " + level + (expanded ? " " : " un") + "expanded, width = " + iconW);
    }

    return result;
  }
}

package spacecheck.images；
导入java.awt.Color；
导入java.awt.Graphics；
导入java.awt.image.buffereImage；
导入java.util.ArrayList；
导入javax.swing.ImageIcon；
导入javax.swing.JFrame；
导入javax.swing.JLabel；
导入javax.swing.JPanel；
/**
*表示目录树中使用的图标；处理“展开”和
*“未展开”目录以及表示不同
*水平。
*@author-rcook
*
*/
公共类树
{
未展开的公共静态int=1；
公共静态int=2；
@SuppressWarnings（{“未使用”}）
私有void say（String msg）{System.out.println（msg）；}
私有静态图像图标expandedIcon=null；
私有静态ImageIcon unexpandedIcon=null；
私有静态int-iconHeight=0；
私有静态int-iconWidth=0；
私有静态ArrayList CacheDexPandeDictions=new ArrayList（）；
私有静态ArrayList cachedUnexpandedIcons=新ArrayList（）；
静止的
{
expandedIcon=newImageIcon（TreeIcon.class.getResource（“images/Expanded.png”）；
unexpandedIcon=newImageIcon（TreeIcon.class.getResource（“images/Unexpanded.png”）；
iconHeight=unexpandedIcon.getIconHeight（）；
iconWidth=unexpandedIcon.getIconWidth（）；
}