1
謝謝你試圖幫助我。請幫助：當使用GridLayout（20,20）時，JPanel中的JButtons網格顯示一個JButton而不是400.
我想創建一個20 * 20平方的網格。它用於我的A-Star算法演示。 對於實驗目的，我寫了下面的代碼：
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
class Node extends JButton {
Node(){
super();
setSize(new Dimension(20,20));
}
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.white);
g.fillRect(0,0,getHeight(),getWidth());
}
}
public class Map
{
static final int n = 20;
JPanel p;
public JPanel init() {
p=new JPanel();
p.setLayout(new GridLayout(n, n));
p.setBackground(Color.black);
p.setFont(new Font("SansSerif", Font.BOLD, 24));
for(int i = 0; i < n; i++) {
for(int j = 0; j < n; j++) {
p.add(new Node());
}
}
return p;
}
}
public class Display extends JApplet{
public void init(){
Map m=new Map();
add(m.init());
}
}`
我得到了以下的輸出： 因爲我缺乏信譽10
但是請加載代碼& check.I不能發佈圖片，當我我試圖添加實驗代碼與我的原代碼演示 它沒有顯示所需的輸出。我的原始代碼如下：
import java.util.ArrayList;
import javax.swing.*;
import java.awt.*;
public class Node extends JButton implements Comparable<Node> {
/* Nodes that this is connected to */
private Node north;
private Node east;
private Node south;
private Node west;
private ArrayList<Node> neighbourList;
private boolean visited;
private float g;
private float h;
private Node parent;
private int x;
private int y;
private boolean isObstacle;
private boolean isStart;
private boolean isGoal;
Node(int x, int y) {
super();
neighbourList = new ArrayList<Node>();
this.x = x;
this.y = y;
this.visited = false;
this.g = Integer.MAX_VALUE;
this.isObstacle = false;
this.isStart = false;
this.isGoal = false;
}
public void setNorth(Node north) {
//replace the old Node with the new one in the neighbourList
if (neighbourList.contains(this.north))
neighbourList.remove(this.north);
neighbourList.add(north);
//set the new Node
this.north = north;
}
public void setEast(Node east) {
//replace the old Node with the new one in the neighbourList
if (neighbourList.contains(this.east))
neighbourList.remove(this.east);
neighbourList.add(east);
//set the new Node
this.east = east;
}
public void setSouth(Node south) {
//replace the old Node with the new one in the neighbourList
if (neighbourList.contains(this.south))
neighbourList.remove(this.south);
neighbourList.add(south);
//set the new Node
this.south = south;
}
public void setWest(Node west) {
//replace the old Node with the new one in the neighbourList
if (neighbourList.contains(this.west))
neighbourList.remove(this.west);
neighbourList.add(west);
//set the new Node
this.west = west;
}
public ArrayList<Node> getneighbourList() {
return neighbourList;
}
public boolean isVisited() {
return visited;
}
public void setVisited(boolean visited) {
this.visited = visited;
}
public float getG() {
return g;
}
public void setG(float f) {
this.g = f;
}
public Node getParent() {
return parent;
}
public void setParent(Node parent) {
this.parent = parent;
}
public float getH() {
return h;
}
public void setH(float h) {
this.h = h;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public boolean isObstacle() {
return isObstacle;
}
public void setObstacle(boolean isObstacle) {
this.isObstacle = isObstacle;
}
public boolean isStart() {
return isStart;
}
public void setStart(boolean isStart) {
this.isStart = isStart;
}
public boolean isGoal() {
return isGoal;
}
public void setGoal(boolean isGoal) {
this.isGoal = isGoal;
}
public boolean equals(Node node) {
return (node.x == x) && (node.y == y);
}
public int compareTo(Node otherNode) {
float thisTotalDistanceFromGoal = h + g;
float otherTotalDistanceFromGoal = otherNode.getH() + otherNode.getG();
if (thisTotalDistanceFromGoal < otherTotalDistanceFromGoal)
return -1;
else if (thisTotalDistanceFromGoal > otherTotalDistanceFromGoal)
return 1;
else
return 0;
}
protected void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.white);
g.fillRect(0,0,getHeight()-1,getWidth()-1);
}
}
public class Map {
private int mapWidth;
private int mapHeight;
private ArrayList<ArrayList<Node>> map;
private int startLocationX = 0;
private int startLocationY = 0;
private int goalLocationX = 0;
private int goalLocationY = 0;
private int[][] obstacleMap;
private JPanel p;
private Logger log = new Logger();
Image buffer;
Map(int mapWidth, int mapHeight, int[][] obstacleMap) {
this.mapWidth = mapWidth;
this.mapHeight = mapHeight;
this.obstacleMap = obstacleMap;
createMap();
log.addToLog("\tMap Created");
registerEdges();
log.addToLog("\tMap Node edges registered");
}
private void createMap() {
Node node;
map = new ArrayList<ArrayList<Node>>();
for (int x=0; x<mapWidth; x++) {
map.add(new ArrayList<Node>());
for (int y=0; y<mapHeight; y++) {
node = new Node(x,y);
if (obstacleMap[x][y] == 1)
node.setObstacle(true);
map.get(x).add(node);
}
}
}
/**
* Registers the nodes edges (connections to its neighbours).
*/
private void registerEdges() {
for (int x = 0; x < mapWidth-1; x++) {
for (int y = 0; y < mapHeight-1; y++) {
Node node = map.get(x).get(y);
if (!node.isObstacle()){
if (!(y==0))
node.setNorth(map.get(x).get(y-1));
if (!(x==mapWidth))
node.setEast(map.get(x+1).get(y));
if (!(y==mapHeight))
node.setSouth(map.get(x).get(y+1));
if (!(x==0))
node.setWest(map.get(x-1).get(y));
}
}
}
}
public ArrayList<ArrayList<Node>> getNodes() {
return map;
}
public void setObstacle(int x, int y, boolean isObstacle) {
map.get(x).get(y).setObstacle(isObstacle);
}
public Node getNode(int x, int y) {
return map.get(x).get(y);
}
public void setStartLocation(Node start) {
map.get(startLocationX).get(startLocationY).setStart(false);
map.get(start.getX()).get(start.getY()).setStart(true);
startLocationX = start.getX();
startLocationY = start.getY();
}
public void setStartLocation(int x, int y) {
map.get(startLocationX).get(startLocationY).setStart(false);
map.get(x).get(y).setStart(true);
startLocationX = x;
startLocationY = y;
}
public void setGoalLocation(Node goal) {
map.get(goalLocationX).get(goalLocationY).setGoal(false);
map.get(goal.getX()).get(goal.getY()).setGoal(true);
goalLocationX = goal.getX();
goalLocationY = goal.getY();
}
public void setGoalLocation(int x, int y) {
map.get(goalLocationX).get(goalLocationY).setGoal(false);
map.get(x).get(y).setGoal(true);
goalLocationX = x;
goalLocationY = y;
}
public int getStartLocationX() {
return startLocationX;
}
public int getStartLocationY() {
return startLocationY;
}
public Node getStartNode() {
return map.get(startLocationX).get(startLocationY);
}
public int getGoalLocationX() {
return goalLocationX;
}
public int getGoalLocationY() {
return goalLocationY;
}
public Node getGoalLocation() {
return map.get(goalLocationX).get(goalLocationY);
}
public float getDistanceBetween(Node node1, Node node2) {
//if the nodes are on top or next to each other, return 1
if (node1.getX() == node2.getX() || node1.getY() == node2.getY()){
return 1;
} else { //if they are diagonal to each other return diagonal distance: sqrt(1^2+1^2)
return (float) 1.4;
}
}
public int getMapWidth() {
return mapWidth;
}
public int getMapHeight() {
return mapHeight;
}
public JPanel init(){
int n=20;
p=new JPanel();
p.setLayout(new GridLayout(n, n));
p.setSize(400,400);
p.setFont(new Font("SansSerif", Font.BOLD, 24));
for(int i = 0; i < n; i++) {
for(int j = 0; j < n; j++) {
p.add(map.get(j).get(i));
}
}
return p;
}
public void clear() {
startLocationX = 0;
startLocationY = 0;
goalLocationX = 0;
goalLocationY = 0;
createMap();
registerEdges();
}
}
public class Display extends JApplet
{
private static int[][] M = {{0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0},
{0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,1,1,0},
{0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0},
{0,0,0,0,1,1,0,0,1,0,0,0,0,0,0,1,1,0,0,0},
{0,1,1,1,1,0,0,1,1,0,0,0,0,0,1,1,0,0,0,0},
{0,0,0,0,0,0,0,1,0,0,0,0,0,1,1,0,0,0,0,0},
{1,1,1,1,1,1,1,1,0,0,0,0,1,1,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,1,1,0,0,0,0,1,1,0,0,0,0},
{0,0,0,0,0,0,0,1,1,0,0,0,1,1,1,0,0,0,0,0},
{0,0,0,0,0,0,1,1,0,0,0,0,1,0,0,0,0,0,0,0},
{0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}};
public void init()
{
JRootPane rootPane = this.getRootPane();
rootPane.putClientProperty("defeatSystemEventQueueCheck", Boolean.TRUE);
Map m=new Map(20,20,M);
add(m.init());
}
}
這是我從上面的代碼得到的輸出： 因爲我缺乏信譽10
'擴展JApplet'爲什麼（哦，爲什麼）一個小程序？開發和調試應用程序要容易得多，即使我正在開發一個applet，我也會先在應用程序中使用它。如果這是由於規格。由老師，請參考[爲什麼CS老師應該停止教Java applets]（http://programmers.blogoverflow.com/2013/05/why-cs-teachers-should-stop-teaching-java-applets/）。 –
我花了幾分鐘試圖讓第二個代碼編譯，然後我停了下來。爲了更快地獲得更好的幫助，請發佈[SSCCE]（http://sscce.org/）。 –