所以我在网格中绘制几个自定义 JComponets。就像一个简单的战舰游戏。然而我想给它们添加透明度。它第一次渲染得很好,但如果我调用重绘,那么 alpha 级别就会消失。然后我可以调整框架的大小,它会自动更新它并具有正确的透明度。
public class Cell extends JComponent implements MouseListener{
public static int CELL_SIZE=50;
private boolean hit = false;
private boolean hasShip = false;
private GridPoint location;
private boolean highlighted = false;
private GameBoard parent;
public static final Color HIT = new Color(Color.RED.getRed(),Color.RED.getGreen(),Color.RED.getBlue(),123);
public static final Color MISS = new Color(80,100,200,123);
public static final Color DEFAULT = new Color(0,0,(150),123);
public static final Color HIGHLIGHT = new Color(255,255,255,50);
public static final Color BORDER = new Color(0,0,40,123);
public Cell()
{
setSize(Cell.CELL_SIZE,Cell.CELL_SIZE);
}
public Cell(GridPoint g, GameBoard p)
{
setOpaque(false);
addMouseListener(this);
parent = p;
setGridLocation(g);
setLocation(CELL_SIZE*location.getX(), CELL_SIZE*location.getY());
setSize(Cell.CELL_SIZE,Cell.CELL_SIZE);
}
public void paintComponent(Graphics g)
{
if(hit == false)
{
if(highlighted)
{
g.setColor(HIGHLIGHT);
g.fillRect(0, 0, Cell.CELL_SIZE, Cell.CELL_SIZE);
}
g.setColor(DEFAULT);
g.fillRect(0, 0, Cell.CELL_SIZE, Cell.CELL_SIZE);
}
else
{
if(hasShip)
{
g.setColor(Cell.HIT);
g.fillRect(0, 0, Cell.CELL_SIZE, Cell.CELL_SIZE);
}
else
{
g.setColor(Cell.MISS);
g.fillRect(0, 0, Cell.CELL_SIZE, Cell.CELL_SIZE);
}
}
g.setColor(Cell.BORDER);
g.drawRect(0, 0, Cell.CELL_SIZE, Cell.CELL_SIZE);
}
public GridPoint getGridLocation() {
return location;
}
public void setGridLocation(GridPoint location) {
this.location = location;
}
@Override
public void mouseClicked(MouseEvent e) {
hit = true;
repaint();
}
@Override
public void mouseEntered(MouseEvent e)
{
highlighted = true;
repaint();
}
@Override
public void mouseExited(MouseEvent e)
{
highlighted = false;
repaint();
}
@Override
public void mousePressed(MouseEvent e) {
}
@Override
public void mouseReleased(MouseEvent e) {
}
}
最佳答案
如果将以下行添加到 paintComponent
方法的开头,它应该可以工作。
float alpha = 0.2f;
((Graphics2D) g).setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
alpha 0.0f 表示完全透明,1.0f 表示不透明。
关于java - JComponent 在重绘时不保持透明度,但在调整大小时保持透明度,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48550751/