Java 将keyEvent应用于方法
我创建了这个方法:Java 将keyEvent应用于方法,java,swing,netbeans,jcombobox,keyevent,Java,Swing,Netbeans,Jcombobox,Keyevent,我创建了这个方法: public void comboS() { ResultSet rset = null; String sch = ((JTextField) ComboItemName.getEditor().getEditorComponent()).getText(); try { rset = new JDBC.DB().getData("SELECT * FROM item_reg WHERE id LIKE '" +
public void comboS() {
ResultSet rset = null;
String sch = ((JTextField) ComboItemName.getEditor().getEditorComponent()).getText();
try {
rset = new JDBC.DB().getData("SELECT * FROM item_reg WHERE id LIKE '" + sch + "%';");
} catch (Exception e) {
System.out.println(e);
}
ComboItemName.removeAllItems();
try {
while (rset.next()) {
String item = rset.getString("id");
ComboItemName.addItem(item);
}
} catch (SQLException ex) {
Logger.getLogger(jfilechooser.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println(sch);
ComboItemName.setSelectedItem(null);
ComboItemName.setPopupVisible(true);
((JTextField) ComboItemName.getEditor().getEditorComponent()).setText(sch);
}
我在JComboBox(ComboItemName)的actionPerformed中调用此方法…当我键入HDD并按enter键时,它会显示数据库中硬盘的所有ID..但我希望在键入HDD时显示此ID。我认为这样的方法应该应用keyEvent
public void comboS(java.awt.event.KeyEvent evt)
但是我不知道如何调用这个方法以及在组合框中的位置。请给我一些帮助。谢谢。
像这样
要在组合框上附加标签,首先您的组合框必须是可编辑的
jComboBox1.setEditable(true);
然后按如下方式连接KeyListener:
jComboBox1.getEditor().getEditorComponent().addKeyListener(new KeyListener() {
@Override
public void keyTyped(KeyEvent e) {
System.out.println(e.getKeyChar() + " KEY_TYPED DETECTED. \n");
}
@Override
public void keyPressed(KeyEvent e) {
System.out.println(e.getKeyChar() + " KEY_PRESS DETECTED. \n");
}
@Override
public void keyReleased(KeyEvent e) {
System.out.println(e.getKeyChar() + " KEY_RELEASE DETECTED. \n");
}
});
就这么简单:)
更新
正如@alex2410所指出的那样,最好使用。以下是如何:
final JTextComponent tc = (JTextComponent) jComboBox1.getEditor().getEditorComponent();
tc.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void insertUpdate(DocumentEvent e) {
System.out.println("Combo Value is: " + tc.getText() + " . \n");
}
@Override
public void removeUpdate(DocumentEvent e) {
System.out.println("Combo Value is: " + tc.getText() + " . \n");
}
@Override
public void changedUpdate(DocumentEvent e) {
System.out.println("Combo Value is: " + tc.getText() + " . \n");
}
});
作为旁注,请坚持在编辑器组件上使用此功能,下面是一个示例:
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
public class Example extends JFrame {
public Example() {
JComboBox comboBox = new JComboBox(new String[]{"1","2"});
comboBox.setEditable(true);
((JTextComponent)comboBox.getEditor().getEditorComponent()).getDocument().addDocumentListener(new DocumentListener() {
@Override
public void removeUpdate(DocumentEvent arg0) {
validateHDD(arg0);
}
@Override
public void insertUpdate(DocumentEvent arg0) {
validateHDD(arg0);
}
@Override
public void changedUpdate(DocumentEvent arg0) {
validateHDD(arg0);
}
private void validateHDD(DocumentEvent arg0) {
try {
String text = arg0.getDocument().getText(0, arg0.getDocument().getLength());
if(text.equals("HDD")){
System.out.println("HDD entered");
//call your method here
}
} catch (BadLocationException e) {
e.printStackTrace();
}
}
});
add(comboBox);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
Example frame = new Example();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
validatehd
validate如果您在JComboBox
的编辑器中输入了HDD,然后执行一些逻辑(如果是真的)。Ok然后在调用..JComboBox ActionExecuted或Combobobox任意事件的地方初始化Combo-1后您将连接KeyListenerKeyListener
这是低级实现,而不是需要在编辑器组件上使用DocumentListener
代码>。如果您是在NetBeans中执行此操作,则将此代码添加到构造函数的initComponents()之后代码>方法,用ComboItemName
替换JCombox1
,但所有这些都是在构造函数中完成的..但是我的应用程序在其中创建了带有拖放功能的组合框..在JSP中解决方案是什么不完全是HDD任何id从数据库HDD用于硬盘MON用于监视器