Question

我有一个'格式化'字段 - 即它最终必须是这样的形式：xx / xxxx / xx 我想这样做，以便在打字时你自动添加'/'。

我想要拼凑的方式是这样的：

JTextField field = new JTextField ("xx/xxxx/xx");

// a focus listener to clear the "xx/xxxx/xx" on focus & restore on focus-out
// the override the 'document' with this:
field.setDocument (new PlainDocument () {
    public void insertString (int off, String str, AttributeSet attr) throws BadLocationException {
      if (off == 2 || off == 7) {
        super.insertString (off + 1, str + "/", attr);
      }
    }
}

这似乎会破坏 - 我如何正确处理它：xx / xx ..到xx？我认为让他们删除'/'是好的。

我觉得应该有更好的方法吗？也许我可以使用的图书馆？除了我......特别的东西。

感谢你的任何输入!!

Answer 1

嗯，您可以使用JFormattedTextField查看下面的示例，这将创建一个JFormattedTextField whic只接受数字并将其放入XX / XXXX / XX形式：

import java.awt.Dimension;
import java.awt.FlowLayout;
import java.text.ParseException;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.text.MaskFormatter;

public class FormattedTextFieldExample extends JFrame {

    public FormattedTextFieldExample() {
        initComponents();
    }

    private void initComponents() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(new Dimension(200, 200));
        getContentPane().setLayout(new FlowLayout(FlowLayout.LEFT));

        MaskFormatter mask = null;
        try {
            //
            // Create a MaskFormatter for accepting phone number, the # symbol accept
            // only a number. We can also set the empty value with a place holder
            // character.
            //
            mask = new MaskFormatter("##/####/##");
            mask.setPlaceholderCharacter('_');
        } catch (ParseException e) {
            e.printStackTrace();
        }

        //
        // Create a formatted text field that accept a valid phone number.
        //
        JFormattedTextField phoneField = new JFormattedTextField(mask);
        phoneField.setPreferredSize(new Dimension(100, 20));
        getContentPane().add(phoneField);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            public void run() {
                new FormattedTextFieldExample().setVisible(true);
            }
        });
    }
}

参考：

http://www.kodejava.org/examples/234.html

Answer 2

为此，我做到了这一点：

JTextField field = new JTextField ();

field.setDocument (new PlainDocument () {
  public void insertString (int off, String str, AttributeSet attr) throws BadLocationException {
    if (off < 10) {  // max size clause
      if (off == 1 || off == 6) { // insert the '/' occasionally
        str = str + "/";
      }
      super.insertString (off, str, attr);
    }
  }
});

field.setText ("xx/xxxx/xx"); // set AFTER otherwise default won't show up!
field.setForeground (ColorConstants.DARK_GRAY_080); // make it light! 
field.addFocusListener (new ClearingFocusListener (field)); // could be done in an anonymous inner class - but I use it other places

private static class ClearingFocusListener implements FocusListener {
  final private String initialText;
  final private JTextField field;

  public ClearingFocusListener (final JTextField field) {
    this.initialText = field.getText ();
    this.field = field;
  }

  @Override
  public void focusGained (FocusEvent e) {
    if (initialText.equals (field.getText ())) {
      field.setText ("");
      field.setForeground (ColorConstants.DARK_GRAY_080);
    }
  }

  @Override
  public void focusLost (FocusEvent e) {
    if ("".equals (field.getText ())) {
      field.setText (initialText);
      field.setForeground (ColorConstants.LIGHT_GRAY_220);
    }
  }
}

这与另一个解决方案的不同之处在于，当没有文本时，'/'不存在，它被添加到正确的位置。它目前没有处理任何替换的东西 - 呃。：/

JTextfield在键入时动态添加文本

2 个答案: