加上在Java组合框项目运行 [英] add items runtime on combobox in java

问题描述

我创建了一个的组合框在的秋千的，我想在另一个函数上添加项目。但问题是，数据项都没有显示调用该功能后：

 公共无效为addItems（）
{
    combo.addItem（）;
    //我想在这里补充项目正在调用该功能时，
    //但这些项目不调用此函数后显示
    //我打电话是按钮点击此功能
}
 

解决方案

在此 SSCCE 对我的作品>

 进口java.awt.BorderLayout中;
进口java.awt.event.ActionEvent中;
进口java.awt.event.ActionListener;进口javax.swing.JButton中;
进口javax.swing.JComboBox中;
进口javax.swing.JFrame中;
进口javax.swing.SwingUtilities中;
进口javax.swing.UnsupportedLookAndFeelException;公共类TestComboBox {    私人诠释计数= 0;    保护无效initUI（）{
        最终的JFrame帧=新的JFrame（TestComboBox.class.getSimpleName（））;
        frame.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
        最终的JComboBox组合框=新JComboBox中（新的对象[] {东西，东西，哔}）;
        JButton的增加=的新的JButton（添加项目）;
        add.addActionListener（新的ActionListener（）{            @覆盖
            公共无效的actionPerformed（ActionEvent的五）{
                comboBox.addItem（本期特价货品+计数++）;
            }
        }）;
        frame.add（组合框）;
        frame.add（添加，BorderLayout.SOUTH）;
        frame.pack（）;
        frame.setBounds（50，50，300，frame.getHeight（））;
        frame.setVisible（真）;
    }    公共静态无效的主要（字串[] args）抛出了ClassNotFoundException，InstantiationException，IllegalAccessException，
            UnsupportedLookAndFeelException {
        SwingUtilities.invokeLater（Runnable的新（）{            @覆盖
            公共无效的run（）{
                新TestComboBox（）initUI（）。
            }
        }）;
    }
}
 

I have created a comboBox in Swing and I want to add items on it in another function. But the problem is that items are not displaying after calling that function:

public void addItems()
{
    combo.addItem("");
    // i want to add items here when this function is being called
    // but those items are not displaying after calling this function
    // i m calling this function on button click
}

解决方案

Works for me in this SSCCE:

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.UnsupportedLookAndFeelException;

public class TestComboBox {

    private int count = 0;

    protected void initUI() {
        final JFrame frame = new JFrame(TestComboBox.class.getSimpleName());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        final JComboBox comboBox = new JComboBox(new Object[] { "Something", "Stuff", "Beep" });
        JButton add = new JButton("Add item");
        add.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                comboBox.addItem("Item-" + count++);
            }
        });
        frame.add(comboBox);
        frame.add(add, BorderLayout.SOUTH);
        frame.pack();
        frame.setBounds(50, 50, 300, frame.getHeight());
        frame.setVisible(true);
    }

    public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException,
            UnsupportedLookAndFeelException {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new TestComboBox().initUI();
            }
        });
    }
}

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