尝试使用鼠标侦听器在数组中显示图像

Question

I have trying to learn about GUI and I created an array of ImageIcon that contains 3 pictures. I want to make it so the user can keep clicking and a new picture will show up. I am trying to use actionMouseListener but it only displays one picture that wont change. I'm pretty new to this so any advice on the most efficient way would be great because once this works I am hoping to add more pictures. I am also getting a really weird output in my console that I have never seen before and I have no idea what it means:

2015-11-12 17:49:33.656 java[22322:1488426] CoreText: *** Unmapped   
"e\uFE0F" <CTFont: 0x7fa89f0842a0>{name = .SFNSText-Regular, size = 
13.000000, matrix = 0x0, descriptor = <CTFontDescriptor: 
0x7fa89f084250>{attributes = <CFBasicHash 0x7fa89f0843f0 
[0x7fff77e2d390]>{type = mutable dict, count = 1,
entries =>
2 : <CFString 0x7fff7a657710 [0x7fff77e2d390]>{contents =  
"NSFontNameAttribute"} = <CFString 0x7fff7a64b5d0 [0x7fff77e2d390]>   
{contents = ".SFNSText-Regular"}
}
>}}

My code looks like

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
@SuppressWarnings("serial")
public class AubsGUI extends JFrame 
{
 private JLabel label, label1; // labels that is on our window  
 private JTextField textfield; //  the window will have writing 
 ImageIcon pic[] = new ImageIcon[3];
 JPanel panel;
 public AubsGUI() // constructor 
{
    setLayout (new FlowLayout()); 
    label = new JLabel (" title "); // creating a label 
    add(label); // adding label to the screen 
    textfield = new JTextField(" Heres a Picture ");//creating a text field
    add(textfield); // adding text field to the screen
    for(int i = 0; i < 3; i++)
    {
        pic[i] = new ImageIcon(getClass().getResource(i +".JPG"));
    }
    label1 = new JLabel();
    label1.setIcon(picture());
    add(label1);
    event e = new event(); 
    label1.addMouseListener(e);
}
public ImageIcon picture()
{
    int i = 0;
    i++;
    return  pic[i];
}
public class event implements MouseListener
{
    public void mouseClicked(MouseEvent e) 
    {
        label1.setIcon(picture());      
    }
    public void mousePressed(MouseEvent e) 
    {


    }
    public void mouseReleased(MouseEvent e) 
    {       
    }
    public void mouseEntered(MouseEvent e) 
    {   
    }
    public void mouseExited(MouseEvent e) 
    {   
    }
}
public static void main (String args [])
{
    AubsGUI aubs = new AubsGUI(); // creates an object aubs from class AubsGUi  
    aubs.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // allows window to close and program to end  
    aubs.pack();
    aubs.setVisible(true); // allows you to see window while program runs
    aubs.setTitle(" title️ ");  
}
}

Answer 1

I don't know about your error, but the problem with your images not swapping is because i is a local variable which ALWAYS starts at 0 , so it can never be more then 1

public ImageIcon picture()
{
    int i = 0;
    i++;
    return  pic[i];
}

Instead, i should be an instance variable, so on each invocation of picture , the value will be maintained

private int i = 0;

public ImageIcon picture() {
    if (i >= pic.length) {
        i = 0;
    }
    ImageIcon icon = pic[i];
    i++;
    return icon;
}

I modified the method slightly, so that when it's first called, the first image is returned, rather then the second

You should also be creating/modifying your UI only from within the context of the Event Dispatching Thread, see Initial Threads for more details.

You might like to have a read through Code Conventions for the Java TM Programming Language , it will make it easier for people to read your code and for you to read others

I "think" the error is related to aubs.setTitle(" title️ "); , which "seems" to have a Unicode character \️ at the end of the text, which the system or font is unable to find a mapping for, but I'm really just having a guess