如何通过执行另一个 class 中的操作来更改一个 class 中的图形颜色？

Question

我是 java 的新手并且很绝望，所以我们开始吧！当我单击菜单中的某个选项时，我试图更改 GUI 内容的颜色，但我不确定如何更改。这是带有 ActionPreform 方法的菜单

    public JMenuBar makeMenuBar(DrawHere drawHTree) {

    JMenuBar menuBar = new JMenuBar();

    JMenu menSize = new JMenu("Color");
    menuBar.add(menSize);

    JMenuItem mitSmall = new JMenuItem("Black");
    mitSmall.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {

            //Do stuff here...
        }

    });
    menSize.add(mitSmall);

    JMenuItem mitMedium = new JMenuItem("Red");
    mitMedium.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {

            // Do stuff here...
        }

    });
    menSize.add(mitMedium);

    JMenuItem mitLarge = new JMenuItem("Cyan");
    mitLarge.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent arg0) {

            // Do stuff here...
        }

    });
    menSize.add(mitLarge);

    return menuBar;
}

这是 class 的一个片段，我想更改其图形颜色

    private void drawHTree(Point location) {

    int x = (int)location.getX();

    int y = (int)location.getY();

    int boxSize = (int)(this.getHeight()*HTREE_SIZE);

    // Rough draft test: 13:50.55 for n = 13
    // Optimized test: 11:42.42 for n = 13
    int n = 5;
    _drawHTree(n,x,y,boxSize);
}

private void _drawHTree(int n, int x, int y, int boxSize) {
    if (n == 0) {
        return;
    }

    Graphics brush = this.getGraphics();

    //brush.setColor(Color.getHSBColor(1,1,1));

    brush.setColor(Color.RED);// <------- NEED HELP HERE! I WANT TO  
                                      // BE ABLE OT CHANGE THIS COLOR 

    ((Graphics2D) brush).draw(new Line2D.Double
            (x, y, x + boxSize, y));
    ((Graphics2D) brush).draw(new Line2D.Double
            (x + boxSize, y - boxSize/2, x + boxSize, y + boxSize/2));
    ((Graphics2D) brush).draw(new Line2D.Double
            (x , y - boxSize/2, x, y + boxSize/2));

    // compute x- and y-coordinates of the 4 half-size H-trees
    int x1 = x - boxSize/2;
    int x2 = x + boxSize/2;
    int y1 = y - boxSize/2;
    int y2 = y + boxSize/2;

    // recursively draw 4 half-size H-trees of order n-1
    _drawHTree(n-1, x1, y1, boxSize/2);
    _drawHTree(n-1, x1, y2, boxSize/2);   
    _drawHTree(n-1, x2 + boxSize/2, y1, boxSize/2);    
    _drawHTree(n-1, x2 + boxSize/2, y2, boxSize/2);    
}

所以，有人有什么想法吗？谢谢 ;D

Answer 1

为什么不直接清除 Color 变量并为该变量写一个 setter。然后而不是在

中直接写颜色

brush.setColor(Color.RED);

使用

 brush.setColor(myColor);

清除你的变量

Color myColor;

public void setMyColor(Color myColor){
     this.mayCOlor = myColor;

在actionPerfomed中直接调用这个方法

如何通过执行另一个 class 中的操作来更改一个 class 中的图形颜色？

How can I change the color of my Graphics in one class by preforming an action from another class?

java

events

user-interface

graphic