[英]Weird output for Graphics code
我正在尝试制作一个Connect Four游戏,以提高我使用Java Graphics和作为学校项目的能力。 游戏的背景将是一个蓝色的JPanel
,游戏板将是一个单独的JPanel,将放置在背景顶部。 请参阅下面的课程:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
public class gameBoard extends JPanel {
private Board bored;
public gameBoard(){
setLayout(new BorderLayout());
bored = new Board();//does not appear in Center Region of gameBoard
add(bored, BorderLayout.CENTER);
}
public void paint(Graphics g){//This line is the one that is acting weird.
//blue rectangle board is here, but when repaint called
//JFrame turns blue and does not add new JPanel called above
g.setColor(Color.BLUE);
g.fillRect(0, 0, 1456, 916);
}
}
和
import java.awt.BasicStroke;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.Graphics2D;
import javax.swing.JPanel;
public class Board extends JPanel {
/*
* 2d array will represent board and take 1's(red) and 2's(black) the nums
* represent pieces, with each redraw of the board, a check will be done to
* compare a sum against blackWin and redWin. Sum will be created by
* summing a continuous line of 1's or 2's going left -> right
*/
public int[][] boardEvalMatrix = new int[6][7];
private final int blackWin = 8, redWin = 4;
public Board() {//1200 x 764
BoardMethods a = new BoardMethods();
a.printBoard(getBoard());
JPanel panelLORDY = new JPanel(new FlowLayout());
repaint();
}
public int[][] getBoard(){
return boardEvalMatrix;
}
public void paint(Graphics g){
g.setColor(Color.BLUE);//Drawing background with actual board as a Test
g.fillRect(0, 0, 1456, 916);//will not remain like this
Graphics2D newG = (Graphics2D) g;
newG.setStroke(new BasicStroke(15));
g.setColor(Color.YELLOW);
for(int a = 0; a < 6; a++)//rows for board --- rowHeight is 127
g.drawRect(128, 68+ (a*127), 1200, 127);
//g.setColor(Color.BLACK);
//newG.setStroke(new BasicStroke(8));
//for(int a = 0; a < 7; a++)//columns for board --- columnWidth is 171
// g.drawRect(208, 152, 70, 10);
//g.drawLine(50,0, 1456, 916); //width 1456 length 916 - school computer monitors
}
}
所以这是怎么回事:
问题1:
当我在gameBoard
类中包含public void paint(Graphics g)
行时,即使没有调用repaint()
并且paint()
方法为空,运行驱动程序时出现的显示也只是一个灰色的JFrame
。 。 但是,当我删除创建paint
方法的行时,问题消失了,并且出现了正确的显示。
问题2:
即使当我在gameBoard
类的paint
方法中放置代码以绘制蓝色矩形并调用repaint()
, JFrame
也是蓝色的,这在一定程度上是正确的。 我知道Java从上到下执行命令,因此我确保将实际游戏板添加到gameBoard
JPanel
的代码是在绘制一个蓝色矩形后出现的,但是没有用。
题:
我做错了什么以及如何解决?
要更改面板的背景色,请使用:
setBackground( Color.BLUE );
在面板上。 然后,无需自定义绘画。
当您重写paint()
并忘记了super.paint()
,您真的会弄乱绘画过程。 paint()
方法负责在面板上绘制子组件。 由于您不调用super.paint()
因此子代永远不会被绘制。
如果由于某种原因确实需要自定义绘画,则应该重写paintComponent()
方法,不要忘记调用super.paintComponent()
。 不要覆盖paint()。
阅读有关“自定义绘画”的Swing教程,尤其是有关“仔细研究绘画机制”的部分, 以获取更多信息和示例。
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