这是一个示例，当您在组件之间移动时，背景会逐渐变暗：
import java.awt.*;import java.awt.event.*;import java.util.Hashtable;import java.util.ArrayList;import javax.swing.*;public class Fader{ // background color when component has focus private Color fadeColor; // steps to fade from original background to fade background private int steps; // apply transition colors at this time interval private int interval; // store transition colors from orginal background to fade background private Hashtable backgroundColors = new Hashtable(); public Fader(Color fadeColor) { this(fadeColor, 10, 50); } public Fader(Color fadeColor, int steps) { this(fadeColor, steps, 50); } public Fader(Color fadeColor, int steps, int interval) { this.fadeColor = fadeColor; this.steps = steps; this.interval = interval; } public Fader add(JComponent component) { // Get colors to be used for fading ArrayList colors = getColors( component.getBackground() ); // FaderTimer will apply colors to the component new FaderTimer( colors, component, interval ); return this; } private ArrayList getColors(Color background) { // Check if the color ArrayList already exists Object o = backgroundColors.get( background ); if (o != null) { return (ArrayList)o; } // Doesn't exist, create fader colors for this background ArrayList colors = new ArrayList( steps + 1 ); colors.add( background ); int rDelta = ( background.getRed() - fadeColor.getRed() ) / steps; int gDelta = ( background.getGreen() - fadeColor.getGreen() ) / steps; int bDelta = ( background.getBlue() - fadeColor.getBlue() ) / steps; for (int i = 1; i < steps; i++) { int rValue = background.getRed() - (i * rDelta); int gValue = background.getGreen() - (i * gDelta); int bValue = background.getBlue() - (i * bDelta); colors.add( new Color(rValue, gValue, bValue) ); } colors.add( fadeColor ); backgroundColors.put(background, colors); return colors; } class FaderTimer implements FocusListener, ActionListener { private ArrayList colors; private JComponent component; private Timer timer; private int alpha; private int increment; FaderTimer(ArrayList colors, JComponent component, int interval) { this.colors = colors; this.component = component; component.addFocusListener( this ); timer = new Timer(interval, this); } public void focusGained(FocusEvent e) { alpha = 0; increment = 1; timer.start(); } public void focusLost(FocusEvent e) { alpha = steps; increment = -1; timer.start(); } public void actionPerformed(ActionEvent e) { alpha += increment; component.setBackground( (Color)colors.get(alpha) ); if (alpha == steps || alpha == 0) timer.stop(); } } public static void main(String[] args) { // Create test components JComponent textField1 = new JTextField(10); textField1.setBackground( Color.YELLOW ); JComponent textField3 = new JTextField(10); JComponent textField4 = new JTextField(10); JComponent button = new JButton("Start"); JComponent checkBox = new JCheckBox("Check Box"); Jframe frame = new Jframe("Fading Background"); frame.setDefaultCloseOperation( Jframe.EXIT_ON_CLOSE ); frame.getContentPane().add(textField1, BorderLayout.NORTH ); frame.getContentPane().add(button, BorderLayout.SOUTH ); frame.getContentPane().add(textField3, BorderLayout.WEST ); frame.getContentPane().add(textField4, BorderLayout.EAST ); frame.getContentPane().add(checkBox); // Gradual Fading (using defaults)// Fader fader = new Fader( new Color(155, 255, 155) ); Fader fader = new Fader( new Color(155, 255, 155), 10, 50 ); fader.add( textField1 ); fader.add( textField3 ); fader.add( checkBox ); // Instant Fading fader = new Fader( new Color(255, 155, 155), 1, 1 ); fader.add( textField4 ); fader.add( button ); frame.pack(); frame.setVisible( true ); }}它使用计时器以指定的间隔更新背景。然后，它仅根据所需的步数在两种颜色之间进行插值。
