如何获取相对于 JFrame 而不是整个屏幕的鼠标坐标

Question

问题： 我想获取鼠标相对于 JFrame 而不是屏幕的坐标。我正在使用带有一组 JPanel 的屏幕，当我单击它们时它们会改变颜色。我该怎么做？

我能找到的大多数解决方案都建议获取组件的坐标，但我不能这样做，因为这意味着它也会找到相对于每个 JPanel 的坐标？

代码：

    public TestCoordinates() {
            initComponents();
            JPanel[][] arrGrid = new JPanel[3][4];
            int tileColour = 0;
    
            //nested for loops create the grid
            for (int y = 0; y < 3; y++) {
                tileColour++;
                for (int x = 0; x < 4; x++) {
                    arrGrid[y][x] = new JPanel();
                    add(arrGrid[y][x]);
                    arrGrid[y][x].setBounds((x * 100) + 100, (y * 100) + 100, 100, 100);
                    arrGrid[y][x].setVisible(true);
    
                    //sets grid colour to alternating colours
                    tileColour++;
                    double tileColourDouble = tileColour;
                    double tileColour2 = tileColourDouble / 2;
                    arrGrid[y][x].setBackground(Color.cyan);
                    if ((tileColour2 == Math.floor(tileColour2)) && !Double.isInfinite(tileColour2)) {
                        arrGrid[y][x].setBackground(Color.green);
                    } else {
                        arrGrid[y][x].setBackground(Color.cyan);
                    }
    
                    //adds mouse listener
                    arrGrid[y][x].addMouseListener(new MouseAdapter() {
                        @Override
                        public void mouseClicked(MouseEvent e) {
                            int yCo = getRow(e.getLocationOnScreen().y - 100);
                            int xCo = getColumn(e.getLocationOnScreen().x - 100);
                            System.out.println(e.getLocationOnScreen());
                            System.out.println(yCo + ", " + xCo);
                            arrGrid[yCo][xCo].setBackground(Color.gray);
                        }
    
                        //converts screen location to single x-coordinate of clicked JPanel's y-coordinate
                        private int getRow(int y) {
                            int row = 0;
                            for (int i = 0; i < y / 100; i++) {
                                row++;
                            }
                            return row;
                        }
    
                        //converts screen location to single x-coordinate of clicked JPanel's x-coordinate
                        private int getColumn(int x) {
                            int column = 0;
                            for (int i = 0; i < x / 100; i++) {
                                column++;
                            }
                            return column;
                        }
                    });
                }
            }
        }

Answer 1

I want to get the coordinates of my mouse... I am using a screen with an array of JPanels that change colour when I click on them.

您不需要鼠标坐标。您可以只使用 MouseEvent 的 getComponent() 方法来获取您单击的组件。然后换个背景。

arrGrid[y][x].addMouseListener(new MouseAdapter() {

您当前的代码正在为每个组件创建唯一的侦听器。这是不必要的。

而是创建一个可以由所有面板共享的通用侦听器。所以在你的循环代码之外你会做这样的事情：

MouseListener ml = new MouseAdapter()
{
    @Override mousePressed(MouseEvent e)
    {
        Component panel = e.getComponent();
        panel.setBackground( Color.GRAY );
    }
};

然后在你的循环代码中你只需做：

arrGrid[y][x].addMouseListener( ml );

如何获取相对于 JFrame 而不是整个屏幕的鼠标坐标

How can I get the mouse coordinates relative to a JFrame rather than the entire screen

java

swing

jframe

jpanel

mouselistener