Java Swing快速构建窗体应用程序


Java Swing的很多属性设置用的方法,而NET用的属性.例如设置窗体标题,java swing用的是setTitle().另外窗体居中用的是setLocationRelativeTo(getOwner()). 获取文本框的值为getText()方法,如下代码所示:

1     public Login() {
2         initComponents();
3         setTitle("登录");
4         setDefaultCloseOperation(EXIT_ON_CLOSE);
5         setVisible(true);
6         setResizable(false);
7         setLocationRelativeTo(getOwner()); //居中显示
8
9     }

1  private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) {
2     // TODO add your handling code here:
3    if(this.txtUserName.getText()!="" && this.txtPWD.getText().toString()!="")
4     {
5         Connection conn = DBConnection.getConnection();
6         PreparedStatement ps = null;
7         ResultSet rs = null;
8         try {
9             ps = conn.prepareStatement(
　　　　　　　　　"select * from users where UserName = ? and password = ?");
10             ps.setString(1,this.txtUserName.getText());//
11             ps.setString(2, this.txtPWD.getText());
12             rs = ps.executeQuery();
13             while (rs.next()) {
14                 User user = new User();
15                 user.setId(rs.getInt("id"));
16                 user.setUsername(rs.getString("UserName"));
17                 user.setPassword(rs.getString("password"));
18
19                 System.out.println(user.toString());
20                 //跳转页面
21                 FrameMain frm=new FrameMain(user.getUsername());
22                 frm.setVisible(true);
23                 this.dispose();//关闭当前窗体
24
25             }
26         } catch (SQLException e) {
27             e.printStackTrace();
28         } finally {
29             DBConnection.closeResultSet(rs);
30             DBConnection.closeStatement(ps);
31             DBConnection.closeConnection(conn);
32         }
33
34      }
35  }

 显示一个窗体是设置其setVisiable(true);关闭一个窗体用的dispose();在登录界面想着输完用户名和密码后,按enter键可以自动登录,在网上搜下,发现了一个变通的方法,就是监听密码框的keypressed事件,当然需要验证一下用户名和密码是否为空(此处未加验证!),如下代码所示:

1    private void txtPWDKeyPressed(java.awt.event.KeyEvent evt) {
2         // TODO add your handling code here:
3         if(evt.getKeyCode()==KeyEvent.VK_ENTER)
4         {
5             //调用登录事件
6             btnLoginActionPerformed(null);
7
8         }
9     }