JTextField的getText方法

Ruthless'' 2020-04-12 05:02:38

为什么无论在文本框里输入什么 str都输出是空白

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do_wa5810 2020-04-23

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楼上正解，增加一个Jbutton,添加点击监听事件 button.addActionListener(new ActionListener())

tianfang 2020-04-12

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你读取的时候，textfild还没有输入值。需要增加一个事件（比如按钮按下），后读取textfild 才能读到输入值

实现圆角矩形边框，hint文字，主要代码： Graphics2D g2d=(Graphics2D) g; g2d.setStroke(new BasicStroke(2,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND)); g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER,0.5f)); g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2d.setColor(borderColor); g2d.drawRoundRect(0, 0, c.getWidth()-4,c.getHeight()-4, 20, 20); JTextField textField = (JTextField) c; if ("".equals(textField.getText())) { g2d.setColor(Color.BLACK); g2d.drawString("请输入文字...", 10, 18); }

java JTextField组件的使用 java JTextField组件的使用 java JTextField组件的使用

主要介绍了Java Swing JTextField文本框的代码示例，文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值，需要的朋友们下面随着小编来一起学习学习吧

主要介绍了Java Swing中的文本框(JTextField)与文本区(JTextArea)使用实例,Swing是一个用于开发Java应用程序用户界面的开发工具包,需要的朋友可以参考下

java+sql房屋租赁系统例： import java.awt.BorderLayout; import javax.swing.JPanel; import javax.swing.JFrame; import java.awt.Dimension; import java.awt.SystemColor; import javax.swing.JLabel; import java.awt.Rectangle; import javax.swing.SwingConstants; import java.awt.Font; import java.awt.Point; import java.sql.Connection; import java.sql.DriverManager; import java.sql.Statement; import javax.swing.JTextField; import javax.swing.JButton; import database.DatabaseUtil; public class DeleteHouseImformation extends JFrame { private static final long serialVersionUID = 1L; private JPanel jContentPane = null; private JLabel jLabel = null; private JLabel jLabel1 = null; private JLabel jLabel2 = null; private JLabel jLabel3 = null; private JLabel jLabel4 = null; private JLabel jLabel5 = null; private JLabel jLabel6 = null; private JTextField jTextField = null; private JTextField jTextField1 = null; private JTextField jTextField2 = null; private JTextField jTextField3 = null; private JTextField jTextField4 = null; private JTextField jTextField5 = null; private JButton jButton = null; private JButton jButton1 = null; private JButton jButton2 = null; /** * This is the default constructor */ public DeleteHouseImformation() { super(); initialize(); } /** * This method initializes this * * @return void */ private void initialize() { this.setSize(453, 286); this.setContentPane(getJContentPane()); this.setTitle("删除房屋信息"); } /** * This method initializes jContentPane * * @return javax.swing.JPanel */ private JPanel getJContentPane() { if (jContentPane == null) { jLabel6 = new JLabel(); jLabel6.setText("HouseStatus："); jLabel6.setSize(new Dimension(97, 18)); jLabel6.setHorizontalAlignment(SwingConstants.RIGHT); jLabel6.setLocation(new Point(18, 210)); jLabel5 = new JLabel(); jLabel5.setText("HouseAddress："); jLabel5.setSize(new Dimension(97, 18)); jLabel5.setHorizontalAlignment(SwingConstants.RIGHT); jLabel5.setLocation(new Point(18, 180)); jLabel4 = new JLabel(); jLabel4.setText("HousseStyle："); jLabel4.setSize(new Dimension(97, 18)); jLabel4.setHorizontalAlignment(SwingConstants.RIGHT); jLabel4.setLocation(new Point(18, 150)); jLabel3 = new JLabel(); jLabel3.setText("MaxNumder："); jLabel3.setSize(new Dimension(97, 18)); jLabel3.setHorizontalAlignment(SwingConstants.RIGHT); jLabel3.setLocation(new Point(18, 120)); jLabel2 = new JLabel(); jLabel2.setText("HouseRent："); jLabel2.setSize(new Dimension(97, 18)); jLabel2.setHorizontalAlignment(SwingConstants.RIGHT); jLabel2.setLocation(new Point(18, 90)); jLabel1 = new JLabel(); jLabel1.setText("HouseID："); jLabel1.setSize(new Dimension(97, 18)); jLabel1.setHorizontalAlignment(SwingConstants.RIGHT); jLabel1.setLocation(new Point(18, 60)); jLabel = new JLabel(); jLabel.setBounds(new Rectangle(75, 11, 295, 41)); jLabel.setHorizontalAlignment(SwingConstants.CENTER); jLabel.setHorizontalTextPosition(SwingConstants.CENTER); jLabel.setFont(new Font("\u534e\u6587\u65b0\u9b4f", Font.BOLD, 24)); jLabel.setText("请输入要删除的房屋信息"); jContentPane = new JPanel(); jContentPane.setLayout(null); jContentPane.setBackground(SystemColor.inactiveCaption); jContentPane.setFont(new Font("Dialog", Font.PLAIN, 12)); jContentPane.add(jLabel, null); jContentPane.add(jLabel1, null); jContentPane.add(jLabel2, null); jContentPane.add(jLabel3, null); jContentPane.add(jLabel4, null); jContentPane.add(jLabel5, null); jContentPane.add(jLabel6, null); jContentPane.add(getJTextField(), null); jContentPane.add(getJTextField1(), null); jContentPane.add(getJTextField2(), null); jContentPane.add(getJTextField3(), null); jContentPane.add(getJTextField4(), null); jContentPane.add(getJTextField5(), null); jContentPane.add(getJButton(), null); jContentPane.add(getJButton1(), null); jContentPane.add(getJButton2(), null); } return jContentPane; } /** * This method initializes jTextField * * @return javax.swing.JTextField */ private JTextField getJTextField() { if (jTextField == null) { jTextField = new JTextField(); jTextField.setLocation(new Point(118, 58)); jTextField.setSize(new Dimension(130, 22)); } return jTextField; } /** * This method initializes jTextField1 * * @return javax.swing.JTextField */ private JTextField getJTextField1() { if (jTextField1 == null) { jTextField1 = new JTextField(); jTextField1.setLocation(new Point(118, 90)); jTextField1.setSize(new Dimension(130, 22)); } return jTextField1; } /** * This method initializes jTextField2 * * @return javax.swing.JTextField */ private JTextField getJTextField2() { if (jTextField2 == null) { jTextField2 = new JTextField(); jTextField2.setLocation(new Point(118, 118)); jTextField2.setSize(new Dimension(130, 22)); } return jTextField2; } /** * This method initializes jTextField3 * * @return javax.swing.JTextField */ private JTextField getJTextField3() { if (jTextField3 == null) { jTextField3 = new JTextField(); jTextField3.setLocation(new Point(118, 152)); jTextField3.setSize(new Dimension(130, 22)); } return jTextField3; } /** * This method initializes jTextField4 * * @return javax.swing.JTextField */ private JTextField getJTextField4() { if (jTextField4 == null) { jTextField4 = new JTextField(); jTextField4.setLocation(new Point(118, 182)); jTextField4.setSize(new Dimension(130, 22)); } return jTextField4; } /** * This method initializes jTextField5 * * @return javax.swing.JTextField */ private JTextField getJTextField5() { if (jTextField5 == null) { jTextField5 = new JTextField(); jTextField5.setLocation(new Point(118, 208)); jTextField5.setSize(new Dimension(130, 22)); } return jTextField5; } /** * This method initializes jButton * * @return javax.swing.JButton */ private JButton getJButton() { if (jButton == null) { jButton = new JButton(); jButton.setLocation(new Point(344, 122)); jButton.setText("删除"); jButton.setSize(new Dimension(64, 29)); jButton.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent e) { //String url = "jdbc:jtds:sqlserver://localhost:1433;DatabaseName=housesystem"; Connection con = DatabaseUtil.getConnection(); try { //Class.forName("net.sourceforge.jtds.jdbc.Driver"); //Connection con = DriverManager.getConnection(url,"sa","123456"); Statement stmt = con.createStatement(); String HouseID = jTextField.getText(); String HouseRent = jTextField1.getText(); String MaxNumder =jTextField2.getText(); String HousseStyle = jTextField3.getText(); String HouseAddress = jTextField4.getText(); String HouseStatus = jTextField5.getText(); String SQL="DELETE FROM HouseImformation WHERE HouseID=('"+HouseID+"') OR HouseRent=('"+HouseRent+"') OR MaxNumder=('"+MaxNumder+"') OR HousseStyle=('"+HousseStyle+"') OR HouseAddress=('"+HouseAddress+"') OR HouseStatus=('"+HouseStatus+"')"; stmt.executeUpdate(SQL); stmt.close(); con.close(); } catch (Exception ex) { } System.out.println("删除成功！");// TODO Auto-generated Event stub actionPerformed() } }); } return jButton; } /** * This method initializes jButton1 * * @return javax.swing.JButton */ private JButton getJButton1() { if (jButton1 == null) { jButton1 = new JButton(); jButton1.setBounds(new Rectangle(348, 159, 64, 29)); jButton1.setText("退出"); jButton1.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent e) { dispose(); // TODO Auto-generated Event stub actionPerformed() } }); } return jButton1; } /** * This method initializes jButton2 * * @return javax.swing.JButton */ private JButton getJButton2() { if (jButton2 == null) { jButton2 = new JButton(); jButton2.setText("清空"); jButton2.setSize(new Dimension(64, 29)); jButton2.setLocation(new Point(350, 199)); jButton2.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent e) { jTextField.setText(""); jTextField1.setText(""); jTextField2.setText(""); jTextField3.setText(""); jTextField4.setText(""); jTextField5.setText(""); // TODO Auto-generated Event stub actionPerformed() } }); } return jButton2; } } // @jve:decl-index=0:visual-constraint="205,9"

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