java如何在netbeans中填充Jcombobox中的项
我在NetBeans中设计了一个表单，它由一个组合框组成。我希望在组合框中预先填充值。我从一个方法中以字符串的arraylist的形式获取这些值。现在我正在尝试将它们添加到组合框中。它正在设置，但不可见。我不明白这有什么问题
/*
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* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package com.digitate.agent.bp.ui;
import com.digitate.agent.bp.ingestor.translation.service.TranslationSpecificationProducer;
import java.util.List;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
/**
*
* @author 125529
*/
public class MainFrame extends javax.swing.JFrame {
/**
* Creates new form NewJFrame1
*/
public MainFrame() {
initComponents();
//addTemplatesToComboBox();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
private void initComponents() {
jToolBar1 = new javax.swing.JToolBar();
jButton1 = new javax.swing.JButton();
jSplitPane1 = new javax.swing.JSplitPane();
jScrollPane3 = new javax.swing.JScrollPane();
jList2 = new javax.swing.JList<>();
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
translationName = new javax.swing.JTextField();
jLabel4 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
jScrollPane2 = new javax.swing.JScrollPane();
mappingTable = new javax.swing.JTable();
destinationTemplateCombo = new javax.swing.JComboBox<>();
sourceFileNameCombo = new javax.swing.JComboBox<>();
submitButton = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jToolBar1.setRollover(true);
jButton1.setText("+");
jButton1.setFocusable(false);
jButton1.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
jButton1.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM);
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jToolBar1.add(jButton1);
jList2.setModel(new javax.swing.AbstractListModel<String>() {
String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
public int getSize() { return strings.length; }
public String getElementAt(int i) { return strings[i]; }
});
jList2.setMaximumSize(new java.awt.Dimension(100, 200));
jList2.setMinimumSize(new java.awt.Dimension(100, 200));
jScrollPane3.setViewportView(jList2);
jSplitPane1.setLeftComponent(jScrollPane3);
jLabel1.setText("Translation Name");
translationName.setToolTipText("");
jLabel4.setText("Source File");
jLabel2.setText("Destination Template");
jLabel5.setText("Mappings");
mappingTable.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null, null}
},
new String [] {
"Destination Field", "Destination Type", "Path/Constant/Script"
}
) {
Class[] types = new Class [] {
java.lang.String.class, java.lang.Object.class, java.lang.String.class
};
boolean[] canEdit = new boolean [] {
false, true, true
};
public Class getColumnClass(int columnIndex) {
return types [columnIndex];
}
public boolean isCellEditable(int rowIndex, int columnIndex) {
return canEdit [columnIndex];
}
});
mappingTable.setColumnSelectionAllowed(true);
jScrollPane2.setViewportView(mappingTable);
mappingTable.getColumnModel().getSelectionModel().setSelectionMode(javax.swing.ListSelectionModel.SINGLE_INTERVAL_SELECTION);
destinationTemplateCombo.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "\"abc\"", "\"xxxc\"", "\"abx\"" }));
destinationTemplateCombo.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
destinationTemplateComboActionPerformed(evt);
}
});
sourceFileNameCombo.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
submitButton.setText("Submit");
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 557, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(sourceFileNameCombo, javax.swing.GroupLayout.PREFERRED_SIZE, 197, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 112, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(translationName, javax.swing.GroupLayout.PREFERRED_SIZE, 319, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2)
.addComponent(jLabel5)
.addComponent(jLabel4, javax.swing.GroupLayout.PREFERRED_SIZE, 122, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(destinationTemplateCombo, javax.swing.GroupLayout.PREFERRED_SIZE, 197, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(245, 245, 245)
.addComponent(submitButton)))
.addContainerGap(21, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(translationName, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(sourceFileNameCombo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(8, 8, 8)
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(destinationTemplateCombo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(58, 58, 58)
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 178, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(34, 34, 34)
.addComponent(submitButton)
.addContainerGap(45, Short.MAX_VALUE))
);
jSplitPane1.setRightComponent(jPanel1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGap(532, 532, 532))
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jSplitPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 619, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jToolBar1, javax.swing.GroupLayout.PREFERRED_SIZE, 25, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jSplitPane1)
.addGap(6, 6, 6))
);
pack();
}// </editor-fold>//GEN-END:initComponents
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
// TODO add your handling code here:
}//GEN-LAST:event_jButton1ActionPerformed
private void destinationTemplateComboActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_destinationTemplateComboActionPerformed
// TODO add your handling code here:
}//GEN-LAST:event_destinationTemplateComboActionPerformed
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Windows".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MainFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
MainFrame mainFrame = new MainFrame();
// mainFrame.addSourceFileToCombobox();
mainFrame.addTemplatesToComboBox();
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new MainFrame().setVisible(true);
}
});
}
//add Template List in destinationTemplateCombo
public void addTemplatesToComboBox(){
TranslationSpecificationProducer translationSpecificationProducer = new TranslationSpecificationProducer();
List<String> templateLists = translationSpecificationProducer.getTemplates();
// String[] items = (String[]) templateLists.toArray();
DefaultComboBoxModel model = new DefaultComboBoxModel();
for(String template: templateLists){
model.addElement(template);
}
destinationTemplateCombo.setModel(model);
setVisible(true);
//System.out.println("Total Items"+destinationTemplateCombo.getItemCount());
//add(destinationTemplateCombo);
}
// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JComboBox<String> destinationTemplateCombo;
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JList<String> jList2;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JScrollPane jScrollPane3;
private javax.swing.JSplitPane jSplitPane1;
private javax.swing.JToolBar jToolBar1;
private javax.swing.JTable mappingTable;
private javax.swing.JComboBox<String> sourceFileNameCombo;
private javax.swing.JButton submitButton;
private javax.swing.JTextField translationName;
// End of variables declaration//GEN-END:variables
}
# 1 楼答案
API中没有任何方法可以将数据从ArrayList填充到组合框
因此，您需要使用一个简单的循环将数据从ArrayList复制到组合框中。您可以使用
JComboBox的addItem(...)方法将项目添加到组合框中：# 2 楼答案
问题是您尚未填充combobx
在java docs上列出了3种方法
第一种方法-在构造函数中调用initComponents（）后，添加代码以构建模型并调用destinationTemplateComb。setModel（myModel）来设置它。因此，构造函数看起来像：
第二种方法：
destinationTemplateCombo。addItem（myString[0]）
第三种方法：
destinationTemplateCombo=newjavax。摆动JComboBox（myString）
第一种方法比其他方法灵活得多