我稍早发布了这个问题并且被告知要将其设为SSCCE所以这里(如果我可以做任何改进,请随时告诉我): 我想知道为什么当点击我的按钮“确认”时,旧的方块消失,重绘的方块没有出现在我的GUI上(用摆动制作)。 Squares类绘制了200个间隔开的正方形,其中ID(0,1,2或3作为字符串)从不同的类中获取(为了这个问题的目的,我们假设它始终为0并且不包括该类)。为了澄清:Squares第一次完美地绘制了所有内容(也检索了正确的ID),但是我希望它在使用新ID单击按钮后重绘所有内容。 广场代码:
import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
import java.util.ArrayList;
public class Squares extends JPanel{
private ArrayList<Rectangle> squares = new ArrayList<Rectangle>();
private String stringID = "0";
public void addSquare(int x, int y, int width, int height, int ID) {
Rectangle rect = new Rectangle(x, y, width, height);
squares.add(rect);
stringID = Integer.toString(ID);
if(ID == 0){
stringID = "";
}
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
FontMetrics fm = g2.getFontMetrics();
int fontAscent = fm.getAscent();
g2.setClip(new Rectangle(0,0,Integer.MAX_VALUE,Integer.MAX_VALUE));
for (Rectangle rect : squares) {
g2.drawString(stringID, rect.x + 7, rect.y + 2 + fontAscent);
g2.draw(rect);
}
}
}
GUI代码:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GUIReserver extends JFrame implements Runnable{
private int myID;
private JButton confirm = new JButton("Check Availability and Confirm Reservation");
private JFrame GUI = new JFrame();
private Squares square;
public GUIReserver(int i) {
this.myID = i;
}
@Override
public void run() {
int rows = 50;
int seatsInRow = 4;
confirm.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent evt) {
GUI.getContentPane().remove(square);
square = new Squares();
int spaceNum = 0;
int rowNum = 0;
int offsetX = 200;
int offsetY = 0;
for(int i = 0; i < rows * seatsInRow; i++){
square.addSquare(rowNum * 31 + offsetX,spaceNum * 21 + 50 + offsetY,20,20, 0); //normally the 4th parameter here would retrieve the ID from the main class
rowNum++;
if(rowNum == 10){
rowNum = 0;
spaceNum++;
}
if(spaceNum == 2){
spaceNum = 3;
rowNum = 0;
}
if(spaceNum == 5){
spaceNum = 0;
offsetY += 140;
}
}
GUI.getContentPane().add(square); //this does not show up at all (could be that it wasn't drawn, could be that it is out of view etc...)
GUI.repaint(); //the line in question
}
});
GUI.setLayout(new FlowLayout());
GUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GUI.setLocation(0,0);
GUI.setExtendedState(JFrame.MAXIMIZED_BOTH);
square = new Squares();
int spaceNum = 0;
int rowNum = 0;
int offsetX = 200;
int offsetY = 0;
for(int i = 0; i < rows * seatsInRow; i++){
square.addSquare(rowNum * 31 + offsetX,spaceNum * 21 + 50 + offsetY,20,20, 0); //normally the 4th parameter here would retrieve the ID from the main class
rowNum++;
if(rowNum == 10){
rowNum = 0;
spaceNum++;
}
if(spaceNum == 2){
spaceNum = 3;
rowNum = 0;
}
if(spaceNum == 5){
spaceNum = 0;
offsetY += 140;
}
}
GUI.getContentPane().add(square); //this shows up the way I wish
GUI.add(confirm);
GUI.pack();
GUI.setVisible(true);
}
}
主要代码:
public class AircraftSeatReservation {
static AircraftSeatReservation me = new AircraftSeatReservation();
private final int rows = 50;
private final int seatsInRow = 4;
private int seatsAvailable = rows * seatsInRow;
private Thread t3;
public static void main(String[] args) {
GUIReserver GR1 = new GUIReserver(3);
me.t3 = new Thread(GR1);
me.t3.start();
}
}
答案 0 :(得分:3)
一个主要问题:你的Squares JPanels首选大小只有20乘20,并且可能实际上是那个大小,因为它似乎被添加到使用FlowLayout的容器中。接下来,您似乎在超出此组件范围的位置绘图,因此可能永远不会看到图纸。考虑允许Squares对象更大,并确保仅在此组件的范围内绘制。
另请注意,有些代码没有意义,包括:
private int myID;
private JTextField row, column, instru draft saved // ???
package question2;ction1, instruction2, seatLabel, rowLabel; // ???
我猜它是
private int myID;
private JTextField row, column, instruction1, instruction2, seatLabel, rowLabel;
这不会为我们编译:
int rows = AircraftSeatReservation.getRows();
int seatsInRow = AircraftSeatReservation.getSeatsInRow(); // and shouldn't this take an int row parameter?
因为我们没有你的AircraftSeatReservation课程(希望你在该课程中没有真正的静态方法)。
我们无法编译或运行您当前的代码。我们不希望看到您的整个程序,而是您应该将代码压缩到仍然编译的最小位,没有与您的问题无关的额外代码,但仍然可以证明您的问题。正如Andrew Thompson建议的那样,为了获得更好的帮助,请创建并发布您的Minimal, Complete, and Verifiable example或Short, Self Contained, Correct Example。
我会尽可能地尝试OOP-ify你的问题,让你分裂和征服。这可能涉及:
SeatClass
枚举,一个可能有两个元素,FIRST和COACH。getBackground(...)
,以便它的颜色取决于座位是否被保留。