How to add Items from an ArrayList of Objects to a JList.

问题

I want to add the toStrings from items in an Arraylist of Objects to a Jlist through a for loop. I tried this.

for (int i = 0; i < customer.slist.size(); i++) {
        ((DefaultListModel) checkOutList.getModel()).addElement(customer.slist.toString());//slist is an array of objects.
    }

But it didnt work. Also NetBeans tells me .addElement()is not a method for a JList when I tried

checkOutList.addElement("anything")

回答1:

instead of

customer.slist.toString()

try:

customer.slist.get(i).toString();

in your code.

回答2:

I have this implementation:

This is custom JList:

@SuppressWarnings("serial")
public class JListCustomered<T extends JListPresentedInterface> extends JList<T>{

private List<T> list;
private List<T> selectedList;

public JListCustomered(List<T> list){
    super();
    this.list=list;
    setCellRenderer(new JListRenderer());
    setModel(new ListModel());
}

public void loadData(List<T> list){
    getSelectedList().clear();
    this.list=list;
    setModel(new ListModel());
}


/** {@link JListCustomered#list} */
public List<T> getList() {
    if(list==null)
        list=new ArrayList<T>();
    return list;
}

/** {@link JListCustomered#selectedList} */
public List<T> getSelectedList() {
    if(selectedList==null)
        selectedList=new ArrayList<T>();
    return selectedList;
}


public class JListRenderer extends JLabel implements ListCellRenderer<T>{
    JSeparator separator;

    private JListRenderer(){
        separator=new JSeparator(JSeparator.HORIZONTAL);
        setOpaque(true);
    }

    /** @see javax.swing.ListCellRenderer#getListCellRendererComponent(javax.swing.JList, java.lang.Object, int, boolean, boolean) */
    public Component getListCellRendererComponent(JList<? extends T> list, T value, int index, boolean isSelected, boolean cellHasFocus) {
        if(value.isSeparator()){
             return separator;
        }

        List<T> selected = getSelectedList();
        if (isSelected) {
            if (!selected.contains(value)) {
                getSelectedList().add(value);
            }
            this.setBackground(getSelectionBackground());
        } else {
            if (selected.contains(value)) {
                getSelectedList().remove(value);
            }
            setBackground(Color.WHITE);
        }
        setFont(list.getFont());
        setText(value.getJListName());
        return this;
    }
}

private class ListModel implements javax.swing.ListModel<T>{

    /** @see javax.swing.ListModel#getSize() */
    public int getSize() {
        return getList().size();
    }

    /** @see javax.swing.ListModel#getElementAt(int) */
    public T getElementAt(int index) {
        return getList().get(index);
    }

    /** @see javax.swing.ListModel#addListDataListener(javax.swing.event.ListDataListener) */
    public void addListDataListener(ListDataListener l) {
    }

    /** @see javax.swing.ListModel#removeListDataListener(javax.swing.event.ListDataListener) */
    public void removeListDataListener(ListDataListener l) {
    }

}
}

below interface for object, which you want add to JList:

public interface JListPresentedInterface {

public String getJListName();
public boolean isSeparator();
}

you can reaload data on JList using method loadData, get selected list getList

来源：https://stackoverflow.com/questions/41081170/how-to-add-items-from-an-arraylist-of-objects-to-a-jlist

标签

java

swing

arraylist