心法领悟046:格式文本框控件的输入。
在JFormatedTextField文本框控件运行期间可以输入非数字或者任意字符,它是在控件失去焦点时进行数据验证的。如果格式不被指定的类型格式器支持,将销毁本次输入。这样用户就必须重新输入标准格式的数据。
import java.awt.EventQueue; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.text.NumberFormat; import javax.swing.JButton; import javax.swing.JFormattedTextField; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.UIManager; import javax.swing.border.EmptyBorder; public class ArrayBound extends JFrame { private JPanel contentPane; private JFormattedTextField codeField; private JTextArea infoArea; /** * Launch the application. */ public static void main(String[] args) { try { UIManager .setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel"); } catch (Throwable e) { e.printStackTrace(); } EventQueue.invokeLater(new Runnable() { public void run() { try { ArrayBound frame = new ArrayBound(); frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } /** * Create the frame. */ public ArrayBound() { setTitle("\u6570\u7EC4\u4E0B\u6807\u8D8A\u754C\u5F02\u5E38"); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setBounds(100, 100, 349, 199); contentPane = new JPanel(); contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); setContentPane(contentPane); contentPane.setLayout(null); JLabel label = new JLabel("\u805A \u4F1A \u8DA3 \u5473 \u9898\uFF1A\u9009\u62E90-5\u7F16\u53F7\u7684\u9898\u76EE"); label.setBounds(10, 10, 317, 27); contentPane.add(label); codeField = new JFormattedTextField(NumberFormat.getIntegerInstance()); codeField.setBounds(77, 40, 122, 30); contentPane.add(codeField); codeField.setColumns(10); JLabel label_2 = new JLabel("\u9898\u76EE\u7F16\u53F7\uFF1A"); label_2.setBounds(10, 46, 67, 18); contentPane.add(label_2); JButton button = new JButton("\u786E\u5B9A"); button.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { do_button_actionPerformed(e); } }); button.setBounds(211, 40, 90, 30); contentPane.add(button); JScrollPane scrollPane = new JScrollPane(); scrollPane.setBounds(10, 76, 317, 79); contentPane.add(scrollPane); infoArea = new JTextArea(); infoArea.setLineWrap(true); scrollPane.setViewportView(infoArea); } private String[] infos = { "50元奖金", "唱一首歌", "学狗叫", "为大家讲一个笑话", "3万元奖金" }; protected void do_button_actionPerformed(ActionEvent e) { // 获取用户输入的整数 int index = ((Number) codeField.getValue()).intValue(); try { infoArea.setText(infos[index]);// 获取指定下标的数组元素显示在文本域控件中 } catch (Exception e2) { infoArea.setText("发生异常:\n" + e2.toString());// 异常信息显示在文本域控件中 } } }