JAVA-SWING入门常见问题集I

 

1、FRAME怎么实现全屏幕
首先要知道屏幕窗口的大小，然后将窗口的位置和大小调整到屏幕窗口的相同大小就ok了。两种方法可实现。

   Ⅰ：
    程序代码如下：
    JFrame frame = new JFrame("Test Full Screen JFrame");
    frame .setUndecorated(true);
    frame .getGraphicsConfiguration().getDevice().setFullScreenWindow(frame );
    frame .setVisible(true);

　Ⅱ：
    JFrame frame = new JFrame("Test Full Screen JFrame");
    Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
    Rectangle bounds =   new   Rectangle(screenSize);
    frame .setBounds(bounds);
    frame .setVisible(true);

2、swing之frame在运行时自动窗口最大化
import javax.swing.*;

        Frame frame = new Frame();
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
        frame.setVisible(true);
3、初始屏幕居中
AstCenterBootstrap astCenter = new AstCenterBootstrap("AstCenter系统"); 
astCenter.pack(); 
Dimension local_size = new Dimension(300, 200); 
astCenter.setSize(local_size); 
astCenter.setLocationRelativeTo(null); 
astCenter.setVisible(true); 

4、swing 显示模态窗口
public class SubDialog extends JDialog {
 public SubDialog(JFrame f)
 {
  super(f,true);
  this.setSize(200,300);
  this.setTitle("dialog");
  this.setLocationRelativeTo(null);
  
 }
 public SubDialog()
 {
  
 }
}

5、子窗口向父窗口传递值、从控件取值
方法一：
父子窗口之间通过一个数据对象联系，该对象属于父窗口，子窗口初始化时保存该对象引用
在子窗口的事件处理对象的函数里，先重子窗口控件取值，再赋予该数据对象的参数
jDialog.fatherData.lostRate = Integer.valueOf(jDialog.jTextField.getText());

6、窗口控件排列

7、弹出提示对话框
JOptionPane

8、枚举中STRING的转换, ENUM.VALUEOF
public enum StrList {
 APPLE,

 PEAR,

 ORANGE
}

  switch(StrList.valueOf(cmd))
  {
  case APPLE:
   break;
  case PEAR:
   break;
  default:
   break;
  }
9、设置关闭窗口，进程即结束
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

10、菜单快捷键设置及事件触发
newItem.setAccelerator(KeyStroke.getKeyStroke('N',CTRL_DOWN_MASK));
11、打开文件及过滤器
打开文件类JFileChooser
过滤器需要自己编写，继承FileFilter
package WindowsPak;
import javax.swing.*;
import javax.swing.filechooser.FileFilter;
import java.io.*;

public final class CapFileFilter extends FileFilter {
 private String extention;
 private String desc;
 public CapFileFilter( String extention, String description )
 {
  super();
  this.extention = extention;
  this.desc = description;
  
 }
 public boolean accept( File f )
 {
  if( null != f )
  {
   if ( f.isDirectory() )
    return true;
   String ext = getExtention( f );
   if ( null != f && this.extention.equals(ext) )
   {
    return true;
   }
  }
  return false;
 }
 public String getDescription( )
 {
  return this.desc;
 }
 private String getExtention( File f )
 {
  if ( null != f )
  {
   String file_name = f.getName();
   int i = file_name.lastIndexOf( '.' );
   return file_name.substring( i + 1 ).toLowerCase();
  }
  return null;
 }
}
12、JTABLE数据刷新
方法1：
主要通过设置MODEL来刷新显示数据
//模式申明
        TableModel dataModel = new AbstractTableModel() { 
            // These methods always need to be implemented. 
            public int getColumnCount() { return column_names.length; } 
            public int getRowCount() { return data.length;} 
            public Object getValueAt(int row, int col) {return data[row][col];} 
 
            // The default implementations of these methods in 
            // AbstractTableModel would work, but we can refine them. 
            public String getColumnName(int column) {return column_names[column];} 
            public Class getColumnClass(int c) {return getValueAt(0, c).getClass();} 
            public boolean isCellEditable(int row, int col) {return true;} 
            public void setValueAt(Object aValue, int row, int column) { 
                System.out.println("Setting value to: " + aValue); 
                data[row][column] = aValue; 
            } 
         };  /*
         //给表设置模式
         //申请表
    table_view = new JTable( dataModel );
    table_view.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); 
   */
  packet_table.setModel( dataModel );

//更新JTABLE
jtable.updateUI();

方法2：
刷新表格数据时使用如下：   
modol.getDataVector().removeAllElements();
modol.fireTableDataChanged();

14、GridBagLayout布局3格两列
GridBagLayout gridbag=new GridBagLayout();
    
     container.setLayout( gridbag );
     //this.setLayout( g_layout );
     //a. 窗体表部分
     tab_pane = addPanel();
     tab_pane.add( "Packet List", addJScrollPane() );
    
     //设置窗体表tab位置
     GridBagConstraints gridBagConstraints_a = new java.awt.GridBagConstraints( 0, 0, 3, 1, 1, 1, GridBagConstraints.BASELINE, GridBagConstraints.BOTH, new Insets(0, 0, 0, 0), 0, 0);
     //GridBagConstraints(gridx,gridy,gridwidth,gridheight,weightx,weighty,anchor,fill,inset,ipadx,ipady);
    
     gridbag.setConstraints( tab_pane, gridBagConstraints_a );
     container.add( tab_pane );
15、JTREE节点选中事件
//添加鼠标左键选中事件
   rtp_tree.addMouseListener( new  MouseAdapter() {
         public   void  mousePressed(MouseEvent e) {
           int  selRow  =  rtp_tree.getRowForLocation(e.getX(), e.getY()); //  返回节点所在的行，-1表示鼠标定位不在显示的单元边界内
          TreePath selPath  =  rtp_tree.getPathForLocation(e.getX(), e.getY()); //  返回指定节点的树路径
    
           boolean  condition  =   true ;
          condition  =  condition  &&  (selRow  !=   - 1 ); //  如果选中
           // condition = condition && (e.getButton() == 1); //  左键 e.getButton() == 1  右键  e.getButton() == 3
          condition  =  condition  &&  (e.getClickCount()  ==   1 ); //  单击
        
    
           //  如果是左键点击
           if  (condition  ==   true   &&  (e.getButton()  ==   1 )) {
            Object[] nodes  =  selPath.getPath();
          
            DefaultMutableTreeNode node  =  (DefaultMutableTreeNode) nodes[nodes.length  -   1 ];
            JOptionPane.showMessageDialog(null , node.toString());
    
          }
        }
      });
16、提示对话框用JOptionPane类
17、编辑树JTREE,使用DefaultCellEditor  
public class CapTreeCellEditorListener extends DefaultCellEditor   {
 public JTree edit_tree = null;
 public CapTreeCellEditorListener( JTextField textField )
 {
  super( textField );
  this.setClickCountToStart(2);
 }
 public boolean  stopCellEditing()
 {
  TreePath tree_path = edit_tree.getSelectionPath();
  
  String new_value = getCellEditorValue().toString();
  edit_tree.getModel().valueForPathChanged( tree_path, new_value );
  System.out.println( "INFO:" + new_value );
  //JOptionPane.showMessageDialog(null , new_value );
  fireEditingCanceled();
  return true;
 }
 public void cancelCellEditing() {
  
  TreePath tree_path = edit_tree.getSelectionPath();
  
  String new_value = getCellEditorValue().toString();
  edit_tree.getModel().valueForPathChanged( tree_path, new_value );
  System.out.println( "INFO:" + new_value );
  
  fireEditingCanceled();
 }
} 

//
DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) rtp_tree.getCellRenderer();
   JTextField textField = new JTextField();
   CapTreeCellEditorListener editor = new CapTreeCellEditorListener( textField );
      editor.edit_tree = rtp_tree;
      rtp_tree.setCellEditor( editor );
18. JTABLE选定行事件
public void valueChanged(ListSelectionEvent e1){
  
  if ( 0 < dataTable.getSelectedRow() )
  { 
   
   int index = (Integer) dataTable.getValueAt( dataTable.getSelectedRow(), 0 ); //行+列
   mFrame.update_tree( index );
  }
 }

ListSelectionModel selectMode = packet_table.getSelectionModel();
         CapTableListSelectionListener capListListener = new CapTableListSelectionListener( this, packet_table );
         selectMode.addListSelectionListener( capListListener );
         selectMode.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        
19. JTREE默认全部展开
//展开树
 private void expandAll(JTree tree, TreePath parent, boolean expand) {
      TreeNode node = (TreeNode) parent.getLastPathComponent();
          if (node.getChildCount() > 0) {
               for (Enumeration e = node.children(); e.hasMoreElements();) {
                     TreeNode n = (TreeNode) e.nextElement();
                      TreePath path = parent.pathByAddingChild(n);
                       expandAll(tree, path, expand);
                 }
           }
       if (expand) {
          tree.expandPath(parent);
       } else {
           tree.collapsePath(parent);
      }
 }
20. JTABLE设置一次只选一行 
selectMode.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

21. 更新树的节点值
((DefaultTreeModel)rtp_tree.getModel()).valueForPathChanged( dst_path, "Destination Mac:" + selected_packet.get_dst_mac() );