我到处寻找答案,但一无所获。我不知道其他人以前是否遇到过这个问题,但我感谢所有帮助,谢谢。
我有一个 100 x 100 的标签网格,让我解释一下我是如何创建它的。我有一个创建并填充字符串数组的方法。下一个方法创建一个标签数组,然后使用 setText() 方法将字符串(从上一个方法创建)添加到标签中。之后的方法获取这些 JLabels 并将它们添加到网格布局的 JPanel 中。然后,我将 JPanel 添加到 JScrollPane,将 JScrollPane 添加到另一个带有空边框的 JPanel,最后将这个 JPanel 添加到 JFrame。这就是我创建网格的方式,我对此很满意,我不想更改它。
我唯一的问题是我无法从主方法修改 JLabels 的图像。我可以从创建和填充 JLabels 的方法中执行此操作,我可以从创建网格的方法中执行此操作,但我无法从主方法中更改 JLabel 的图像。我尝试为此创建一个新方法并在主方法中调用它 - 什么也没有。我还尝试从按钮的 ActionListener 更改它 - 没有再改变。我知道这是可能的,而且我知道我错过了一些非常明显的东西。
请问您能帮忙吗?下面是代码,如果运行它并单击按钮,您会发现什么也没有发生。然而,最奇怪的是我几乎可以从任何地方更改 JLabels 的背景颜色。
package roverMars;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class ArraysGrid extends JPanel {
private static final long serialVersionUID = -464020590200143351L;
final int rows = 50, columns = 50;
static BufferedImage Ahead, Down, Left, Right;
public void ImageLoader() {
try {
Ahead = ImageIO.read(this.getClass().getResource("Ahead.png"));
Down = ImageIO.read(this.getClass().getResource("Down.png"));
Left = ImageIO.read(this.getClass().getResource("Left.png"));
Right = ImageIO.read(this.getClass().getResource("Right.png"));
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("Error occured: " + e);
e.printStackTrace();
}
}
public void StringArray(String[][] labelText) {
int x = 1; // increment rows
for (int i = 0; i < labelText.length; i++) { // x
for (int j = 0; j < labelText.length; j++) { // y
labelText[i][j] = Integer.toString(x); // populate string
x++;
}
}
}
public void JLabelArray(JLabel[][] label, String[][] labelText) {
ImageLoader();
for (int i = 0; i < label.length; i++) { // x
for (int j = 0; j < label.length; j++) { // y
label[i][j] = new JLabel();
label[i][j].setText(labelText[i][j]);
label[i][j].setOpaque(true);
}
}
// Testing to see if image appears
label[0][0] = new JLabel(new ImageIcon(Down));
label[1][0] = new JLabel(new ImageIcon(Right));
}
// Add Labels to Panel,
public void Grid(JPanel Grid, JLabel[][] label) {
String x1[][] = new String[rows][columns];
StringArray(x1);
JLabelArray(label, x1);
int gHeight = label.length, gWidth = label.length;
Grid.setLayout(new GridLayout(gWidth, gHeight));
for (int i = 0; i < label.length; i++) { // x
for (int j = 0; j < label.length; j++) { // y
Grid.add(label[i][j]);
}
}
}
public void Frame(JPanel finalPanel, JPanel Grid) {
// Add Grid to Scroll Pane
JScrollPane x4 = new JScrollPane(Grid);
x4.setPreferredSize(new Dimension(700, 700)); // DO NOT DELETE THIS.
x4.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
x4.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
// Add Scroll Pane to another Panel with the Border
finalPanel.setBackground(new Color(153, 153, 204));
finalPanel.setBorder(BorderFactory.createEmptyBorder(50, 25, 50, 50));
finalPanel.add(x4);
}
// This method to button.
public static void setImage(JLabel l) {
ArraysGrid ag = new ArraysGrid();
ag.ImageLoader();
l = new JLabel(new ImageIcon(Left));
}
static JLabel[][] label = new JLabel[50][50];
public static void main(String[] args) {
ArraysGrid m = new ArraysGrid();
JPanel grid = new JPanel();
JPanel final1 = new JPanel();
m.Grid(grid, label);
m.Frame(final1, grid);
JFrame f = new JFrame();
f.setTitle("Project Testing");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setResizable(true);
f.setVisible(true);
f.setLocation(650, 50);
f.setSize(800, 800);
f.setAlwaysOnTop(true);
f.setBackground(Color.black);
f.add(final1);
JButton button = new JButton("Click Here");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Clicked");
label[1][1].setBackground(Color.RED);
label[2][1] = new JLabel(new ImageIcon(Ahead));
System.out.println(label[2][1].getIcon());
setImage(label[2][2]);
// label[2][2].setIcon((Icon) Ahead); // This throws several errors
}
});
f.add(button, BorderLayout.NORTH);
f.pack();
}
}
请问有人可以帮忙吗?昨天我花了一整天的时间试图让它发挥作用,但一无所获。另外,我对此很陌生,我在这个类上所做的一切都是我在过去几周内才学到的,所以如果您同意,请您解释一下我需要做什么以及为什么。
非常感谢!
最佳答案
我没有太多时间仔细检查它,但您不需要在以下行创建新的 JLabel
对象:
label[2][1] = new JLabel(new ImageIcon(Ahead));
因为它已经在代码的前面创建了。你还应该换行
label[2][2].setIcon((Icon)Ahead); // This throws several errors
至
label[2][2].setIcon(new ImageIcon(Ahead)); // This throws several errors
经过这些更改后,代码可以正常工作。
顺便说一句。你的代码看起来有点难看;)尝试重构它;)这是在我的计算机上运行的代码:
package roverMars;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class ArraysGrid extends JPanel {
private static final long serialVersionUID = -464020590200143351L;
final int rows = 50, columns = 50;
static BufferedImage Ahead, Down, Left, Right;
public void ImageLoader() {
try {
Ahead = ImageIO.read(this.getClass().getResource("Ahead.png"));
Down = ImageIO.read(this.getClass().getResource("Down.png"));
Left = ImageIO.read(this.getClass().getResource("Left.png"));
Right = ImageIO.read(this.getClass().getResource("Right.png"));
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("Error occured: " + e);
e.printStackTrace();
}
}
public void StringArray(String[][] labelText) {
int x = 1; // increment rows
for (int i = 0; i < labelText.length; i++) { // x
for (int j = 0; j < labelText.length; j++) { // y
labelText[i][j] = Integer.toString(x); // populate string
x++;
}
}
}
public void JLabelArray(JLabel[][] label, String[][] labelText) {
ImageLoader();
for (int i = 0; i < label.length; i++) { // x
for (int j = 0; j < label.length; j++) { // y
label[i][j] = new JLabel();
label[i][j].setText(labelText[i][j]);
label[i][j].setOpaque(true);
}
}
// Testing to see if image appears
label[0][0] = new JLabel(new ImageIcon(Down));
label[1][0] = new JLabel(new ImageIcon(Right));
}
// Add Labels to Panel,
public void Grid(JPanel Grid, JLabel[][] label) {
String x1[][] = new String[rows][columns];
StringArray(x1);
JLabelArray(label, x1);
int gHeight = label.length, gWidth = label.length;
Grid.setLayout(new GridLayout(gWidth, gHeight));
for (int i = 0; i < label.length; i++) { // x
for (int j = 0; j < label.length; j++) { // y
Grid.add(label[i][j]);
}
}
}
public void Frame(JPanel finalPanel, JPanel Grid) {
// Add Grid to Scroll Pane
JScrollPane x4 = new JScrollPane(Grid);
x4.setPreferredSize(new Dimension(700, 700)); // DO NOT DELETE THIS.
x4.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
x4.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
// Add Scroll Pane to another Panel with the Border
finalPanel.setBackground(new Color(153, 153, 204));
finalPanel.setBorder(BorderFactory.createEmptyBorder(50, 25, 50, 50));
finalPanel.add(x4);
}
// This method to button.
public static void setImage(JLabel l) {
ArraysGrid ag = new ArraysGrid();
ag.ImageLoader();
l = new JLabel(new ImageIcon(Left));
}
static JLabel[][] label = new JLabel[50][50];
public static void main(String[] args) {
ArraysGrid m = new ArraysGrid();
JPanel grid = new JPanel();
JPanel final1 = new JPanel();
m.Grid(grid, label);
m.Frame(final1, grid);
JFrame f = new JFrame();
f.setTitle("Project Testing");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setResizable(true);
f.setVisible(true);
f.setLocation(650, 50);
f.setSize(800, 800);
f.setAlwaysOnTop(true);
f.setBackground(Color.black);
f.add(final1);
JButton button = new JButton("Click Here");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println("Clicked");
label[1][1].setBackground(Color.RED);
//label[2][1] = new JLabel();
System.out.println(label[2][1].getIcon());
setImage(label[2][2]);
label[2][2].setIcon(new ImageIcon(Ahead)); // This throws several errors
}
});
f.add(button, BorderLayout.NORTH);
f.pack();
}
}
关于java - 从 JButton 更改 JLabel 的图像,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23720248/