[英]How I return the value of jcombobox when I push a jbutton
我是 Java 新手,我想知道在按下JButton
时如何打印从JComboBox
选择的值。 这是我的代码的一部分:
public class inizio extends javax.swing.JFrame {
public inizio() {
initComponents();
}
private void initComponents() {
jComboBox1 = new javax.swing.JComboBox();
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
jComboBox1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jComboBox1ActionPerformed(evt);
}
});
jButton1.setText("jButton1");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(27, 27, 27)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(169, Short.MAX_VALUE)
.addComponent(jButton1)
.addGap(152, 152, 152))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(117, 117, 117)
.addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(52, 52, 52)
.addComponent(jButton1)
.addContainerGap(84, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jComboBox1ActionPerformed(java.awt.event.ActionEvent evt) {
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
}
在private void jButton1ActionPerformed(java.awt.event.ActionEvent evt)
,我如何从evt
中获取JComboBox
的evt
? 谢谢!
您不能从evt
jComboBox
的evt
。 您可以使用jComboBox1.getSelectedItem()
来获取所选项目,因为您的jComboBox1
似乎是一个应该可以从方法内部访问的字段。
PS:如果你还没有这样做,你应该开始使用像eclipse这样的IDE。
jComboBox1.getSelectedItem()
给你物品。 像这样测试它:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
System.out.println(String.valueOf(jComboBox1.getSelectedItem()));
}
jComboBox1
应该是一个成员字段,由您的构造函数设置,以便jButton1ActionPerformed()
使用它:
class inizio {
JComboBox jComboBox1;
inizio() {
jComboBox1 = new JComboBox();
initComponents();
}
}
您可以在此处阅读有关该方法的更多信息。
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