问题描述
我在我的程序中创建了一个网格.下面是用于创建网格的代码.
I have created a grid in my program. Below is the code used to create the grid.
import java.awt.Graphics; import javax.swing.JComponent; import javax.swing.JFrame; class Grid extends JComponent { public void paint(Graphics g) { g.drawRect (10, 10, 800, 500); for (int i = 10; i <= 800; i+= 10) g.drawLine (i, 10, i, 510); for (int i = 10; i <= 500; i+= 10) g.drawLine (10, i, 810, i); } } public class CoreControl { public static void main(String[] a) { JFrame window = new JFrame(); window.setSize(840,560); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.getContentPane().add(new Grid()); window.setVisible(true); } }
我想做的是创建一个函数,该函数将根据我给它的坐标绘制一个矩形(用黑色填充).基本上我想用黑色填充网格的某些单元格,我的想法是在单元格坐标上绘制黑色填充矩形.如何实现这个功能?
What I want to do is to create a function which will draw a rectangle (filled with black color) based on the coordinates that I give it. Basically I want to populate certain cells of the grid with black color and my idea is to draw black filled rectangles on the cell coordinates. How do I make this function?
我尝试创建另一个名为 drawRectangle 的类并在主函数中调用它,例如 window.getContentPane().add(new drawRectangle());但这不起作用(只显示 drawRectangle 而不是网格).
I tried making another class called drawRectangle and called it in the main function like so window.getContentPane().add(new drawRectangle()); however that did not work (only drawRectangle shows up and not the grid).
我还希望能够反复使用此功能来不断创建矩形.
I also want to be able to use this function repeatedly to keep creating rectangles.
如何创建这个函数?
另外,如果您知道我应该构建这个程序的更好方法,请告诉我(我是 Java 新手,所以我愿意接受任何建议).
Also if you know a better way that I should structure this program please let me know (I am new to Java so I am open to any suggestions).
推荐答案
- 不要使用paint,使用paintComponent并且不要忘记调用super.paintComponent
- JComponent 可能不是最佳选择,JPanel 可能是更好的选择
- Graphics#fillRect(int, int, int, int)?
- Don't use paint, use paintComponent and don't forget to call super.paintComponent
- JComponent may not be the best choice, JPanel is probably a better choice
- What's wrong with Graphics#fillRect(int, int, int, int)?
您可以看看 Performing Custom Painting 和 2D 图形了解更多详情.
You might to take a look at Performing Custom Painting and 2D Graphics for more details.
我建议不要尝试使用第二个组件来执行填充.只需在网格类中提供一个方法,该方法提供单元格的 x/y 位置(以网格形式)并在 paintComponent 方法中填充单元格
I'd advice against trying to have a second component to performing the filling. Simply provide a method in you grid class that supplies the cell's x/y position (in grid terms) and fill the cell within the paintComponent method
更新示例
import java.awt.Color; import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Point; import java.util.ArrayList; import java.util.List; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class CoreControl { public static class Grid extends JPanel { private List<Point> fillCells; public Grid() { fillCells = new ArrayList<>(25); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); for (Point fillCell : fillCells) { int cellX = 10 + (fillCell.x * 10); int cellY = 10 + (fillCell.y * 10); g.setColor(Color.RED); g.fillRect(cellX, cellY, 10, 10); } g.setColor(Color.BLACK); g.drawRect(10, 10, 800, 500); for (int i = 10; i <= 800; i += 10) { g.drawLine(i, 10, i, 510); } for (int i = 10; i <= 500; i += 10) { g.drawLine(10, i, 810, i); } } public void fillCell(int x, int y) { fillCells.add(new Point(x, y)); repaint(); } } public static void main(String[] a) { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { } Grid grid = new Grid(); JFrame window = new JFrame(); window.setSize(840, 560); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); window.add(grid); window.setVisible(true); grid.fillCell(0, 0); grid.fillCell(79, 0); grid.fillCell(0, 49); grid.fillCell(79, 49); grid.fillCell(39, 24); } }); } }