JDatePicker不会出现在JFrame上

Question

晚上好，我正在尝试在我的个人项目中实现JDatePicker库，我是该库的初学者，我以前从未使用过，我一直在阅读一些示例和教程，但我没有让这个组件显示在我的JFrame中，如果你们可以帮助我找到错误，我非常感谢您的帮助：

package Frames;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jdatepicker.impl.JDatePanelImpl;
import org.jdatepicker.impl.JDatePickerImpl;
import org.jdatepicker.impl.UtilDateModel;


public class BillForm extends javax.swing.JFrame {

/**
 * Creates new form BillForm
 */
public BillForm() {
    initComponents();
    crearJDatePicker();
}


private void crearJDatePicker (){
    UtilDateModel model = new UtilDateModel();
    //model.setDate(20,04,2014);
    // Need this...
    Properties p = new Properties();
    p.put("text.today", "Today");
    p.put("text.month", "Month");
    p.put("text.year", "Year");
    JDatePanelImpl datePanel = new JDatePanelImpl(model, p);
    // Don't know about the formatter, but there it is...
    JDatePickerImpl datePicker = new JDatePickerImpl(datePanel, new DateLabelFormatter());
    this.add(datePicker);
}

private Date getDate(){
    DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy");
    Date date = new Date();
    try {
        return dateFormat.parse(dateFormat.format(date));
    } catch (ParseException ex) {
        Logger.getLogger(BillForm.class.getName()).log(Level.SEVERE, null, ex);
    }
    return date;
}
public static void main(String args[]) {

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new BillForm().setVisible(true);
        }
    });
}

Answer 1

问题出在您的initComponents方法内，可能是使用GroupLayout ，这是手动尝试和管理的最差的布局管理器之一。

更好的选择是开始手动编码布局（或至少将布局管理器更改为更容易更新的内容）

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Properties;
import javax.swing.JFormattedTextField.AbstractFormatter;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import org.jdatepicker.impl.JDatePanelImpl;
import org.jdatepicker.impl.JDatePickerImpl;
import org.jdatepicker.impl.UtilDateModel;

public class Test {

    public static void main(String[] args) {
        new Test();
    }

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            UtilDateModel model = new UtilDateModel();
            Properties p = new Properties();
            p.put("text.today", "Today");
            p.put("text.month", "Month");
            p.put("text.year", "Year");
            JDatePanelImpl datePanel = new JDatePanelImpl(model, p);
            JDatePickerImpl datePicker = new JDatePickerImpl(datePanel, new DateLabelFormatter());
            setLayout(new GridBagLayout());
            add(datePicker);
        }

    }

    public class DateLabelFormatter extends AbstractFormatter {

        private String datePattern = "yyyy-MM-dd";
        private SimpleDateFormat dateFormatter = new SimpleDateFormat(datePattern);

        @Override
        public Object stringToValue(String text) throws ParseException {
            return dateFormatter.parseObject(text);
        }

        @Override
        public String valueToString(Object value) throws ParseException {
            if (value != null) {
                Calendar cal = (Calendar) value;
                return dateFormatter.format(cal.getTime());
            }

            return "";
        }

    }
}