将值和标签设置为JComboBox [英] Set Value and Label to JComboBox

问题描述

我有一个JComboBox，其中的项目是查询的结果.该组合显示了从查询中获取的所有类别名称，对吗?好的，它可以工作.现在，我需要为每个项目赋予一个值，该值就是产品的ID.

I have a JComboBox where the items are the results of a query. The combo shows all the categories names taken from a query, right? Ok, it works. Now I need to give each item a value, which would be the ID of the product.

这是我到目前为止所得到的:

This is what I've got so far:

    final JComboBox proveedorCombo = new JComboBox();

    contentPanel.add(proveedorCombo);

    ProveedorDAO dao = new ProveedorDAO();

    List<Proveedor> proveedor = dao.getAll();

    Object[][] elementos = new Object[proveedor.size()][2];

    for (int i = 0; i < proveedor.size(); i++) {
        Proveedor p = proveedor.get(i);
        elementos[i][0] = p.getId();
        elementos[i][1] = p.getNombre();
        proveedorCombo.addItem(elementos[i][1]);
    }

如您在代码中所见，每个项目的标签"是它的名称.现在，如何设置每个项目的ID，以便以后进行操作?

As you can see in the code, the "label" of each item is the name of it. Now, how can I set each item its ID so I can manipulate after?

感谢并尝试轻松回答，我最难尝试获取Java东西！哈！

Thanks and try to answer easily, I'm having the hardest time trying to get this Java thing! Ha!

推荐答案

JComboBox默认情况下使用渲染器，而使用toString()方法显示对象数据.因此，您可以创建自己的渲染类以自定义视图.

JComboBox by default uses a renderer wich uses toString() method to display object data. So you can make your own render class to customize the view.

这是它的设计方式.

proveedorCombo.setRenderer( new DefaultListCellRenderer(){

        @Override  
        public Component getListCellRendererComponent(
            JList list, Object value, int index,
            boolean isSelected, boolean cellHasFocus)
        {
            super.getListCellRendererComponent(list, value, index,
                isSelected, cellHasFocus);

                if(value != null){
                 Proveedor proveedor = (Proveedor)value;
                 setText( proveedor.getName());
                }
            return this;
        }
});

另一种骇人听闻的方法是从Proveedor覆盖toString()或使适配器类使用您的toString()，但是此解决方案不像其他解决方案那样灵活.

Another hacky approach is overriding toString() from Proveedor or making your adapter class that uses your toString() but this solution is not much flexible as the other one.

public class Proveedor {

//in some part
@Override
public String toString(){
    return this.nombre;
}

}

如果要从零开始填充，请在组合框中.

In the combobox if you want to populate from zero.

proveedorCombo.setModel(new DefaultComboBox(new Vector<Proveedor>(dao.getAll())));

或者如果您有以前的数据并且想要维护.

Or if you have previous data and you want to maintain.

for(Proveedor p : dao.getAll){
    proveedorCombo.addItem(p);
}

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