透明JButton仍然绘制其背景

Question

我有一个半透明 JPanel。我创建了一个自定义JButton通过扩展JButton，因为我需要一个圆角的按钮，并希望添加一些效果。我制作了不透明的。当我将这个按钮添加到我的半透明JPanel时，它的效果很好。但在翻转后，黑色补丁画在按钮后面，看起来非常糟糕。我在网上搜索了一个解决方案，但无法找到有用的解决方案。这个问题也是在http://www.java.net/node/661798描述，但我没能真正使kirillcool的建议，制定出.....任何帮助将不胜感激

Answer 1

我相信你需要添加：

button.setContentAreaFilled(false); 

Answer 2

不知道，如果有人仍然有兴趣... 您可以通过覆盖paintComponent()方法来解决问题，让Java以您喜欢的任何形状绘制JButton。您只需要使用setBackground()方法将Graphics对象的背景设置为透明。您还需要在使用clearRect()方法清除图形对象之前清除图形对象，然后用JButton的背景Alpha级别再次填充图形对象。这是我的一段代码..它显示覆盖paintComponent()。通过将其粘贴到您的JButton你应该就算得与圆边的JButton其上半TRANSPARANT背景

private int outerRoundRectSize = 10; 
private int innerRoundRectSize = 8; 

public void paintComponent(Graphics g) 
{ 
    int h = getHeight(); 
    int w = getWidth(); 

    Graphics2D g2d = (Graphics2D) g.create(); 
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON); 

    Color GP = null; 

    //////////////get rid of the black background//////////////////////// 
    g2d.setBackground(new Color(0,0,0,0.0f)); 
    g2d.clearRect(0, 0, w, h); 
    g2d.setPaint(new Color(0,0,0,0.3f)); 
    g2d.fillRect(0, 0, w, h); 
    //////////////get rid of the black background//////////////////////// 

    ButtonModel model = getModel(); 
    if(!model.isEnabled()) 
    { 
     setForeground(Color.GRAY); 
     GP = new Color(0.5f,0.2f,0.6f); 
    } 
    else 
    { 
     setForeground(Color.WHITE); 
     if(model.isRollover()) 
     { 
      GP = new Color(0.5f,0.2f,0.6f); 
     } 
     else 
     { 
      GP = new Color(0.0f,1.0f,0.0f); 
     } 
    } 
    g2d.setPaint(GP); 
    Color p1 = null; 
    Color p2 = null; 

    if(getModel().isPressed()) 
    { 
     GP = new Color(1.0f,0.0f,0.0f); 
     g2d.setPaint(GP); 
     p1=new Color(0.12f,0.7f,0.3f); 
     p2=new Color(0.7f,0.5f,0.6f); 
    } 
    else 
    { 
     p1=new Color(0.0f,0.5f,0.7f); 
     p2=new Color(0.0f,1.0f,1.0f); 
     GP = new Color(0.0f,0.0f,1.0f); 
    } 

    RoundRectangle2D.Float r2d = new RoundRectangle2D.Float(0, 0, w - 1, h - 1, outerRoundRectSize, outerRoundRectSize); 
    Shape clip = g2d.getClip(); 
    g2d.clip(r2d); 
    //g2d.fillRect(0, 0, w, h); 
    g2d.fillRoundRect(0, 0, w, h, outerRoundRectSize, outerRoundRectSize); 
    g2d.setClip(clip); 
    g2d.setPaint(p1); 
    g2d.drawRoundRect(0, 0, w - 1, h - 1, outerRoundRectSize,outerRoundRectSize); 
    g2d.setPaint(p2); 
    g2d.drawRoundRect(1, 1, w - 3, h - 3, innerRoundRectSize,innerRoundRectSize); 

    g2d.dispose(); 
    super.paintComponent(g); 
}