Question

如何将getSelectedItem（）从JComboBox转换为int或任何其他东西？即使转换为字符串也无效。 Eclipse说“类型不匹配：无法从Object转换为String”或int或其他。有没有办法实现这个目标？

Answer 1

这里的对象很好用。

import java.awt.*;
import javax.swing.*;

class TestCombo {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                Integer[] numbers = {1,2,3};
                String[] names = {"Ben", "Jill", "Peter"};
                JComboBox numberCombo = new JComboBox(numbers);
                JComboBox nameCombo = new JComboBox(names);
                JPanel p = new JPanel(new GridLayout(0,1,3,3));
                p.add(numberCombo);
                p.add(nameCombo);

                JOptionPane.showMessageDialog(null, p);

                Integer chosenNumber = (Integer)numberCombo.getSelectedItem();
                System.out.println("Chosen Number: " + chosenNumber);
                String chosenName = (String)nameCombo.getSelectedItem();
                System.out.println("Chosen Name: " + chosenName);
            }
        });
    }
}

典型输出：

Chosen Number: 2
Chosen Name: Peter
Press any key to continue . . .

我同意LBFF的评论。你需要回到基础。

Answer 2

答案实际上取决于您在JComboBox开始使用的项目类型。无论你投入什么（例如，使用addItem()或insertItemAt()），你都可以得到它。

Answer 3

您可以将其投射到(String)。

String value = (String) comboBox.getSelectedItem();

Answer 4

//compiled in netbeans

import java.awt.GridLayout;<br>
import javax.swing.JComboBox;<br>
import javax.swing.JOptionPane;<br>
import javax.swing.JPanel;<br>
import javax.swing.SwingUtilities;<br>

class TestCombo {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                Integer[] numbers = {1,2,3};
                String[] names = {"Ben", "Jill", "Peter"};
                JComboBox numberCombo = new JComboBox(numbers);
                JComboBox nameCombo = new JComboBox(names);
                JPanel p = new JPanel(new GridLayout(0,1,3,3));
                p.add(numberCombo);
                p.add(nameCombo);

                JOptionPane.showMessageDialog(null, p);

                Integer chosenNumber = (Integer)numberCombo.getSelectedItem();
                System.out.println("Chosen Number: " + chosenNumber);
                String chosenName = (String)nameCombo.getSelectedItem();
                System.out.println("Chosen Name: " + chosenName);
            }
        });
    }
}

Answer 5

String value = comboBox.getSelectedItem(comboBox.getSelectedIndex());

不需要演员表。

将getSelectedItem（）从JComboBox转换为int或任何其他东西

5 个答案: