netbeans窗体初步

痛定思痛。 2022-08-27 07:55 179阅读 0赞

开始学java,使用netbeans,从开始学做桌面软件开始。

1.做一个MDI窗体

新建一个Frame,在上面在放一个JDesktopPane.再放一个菜单。

再建几个继承自JInternalFrame的类。点选菜单时执行以下代码.

private void jTableTestActionPerformed(java.awt.event.ActionEvent evt) \{

NewJInternalFrame d = new NewJInternalFrame();

jDesktop1.add(d, javax.swing.JLayeredPane.DEFAULT\_LAYER);

d.setVisible(true);

2.使MDI中子窗体不重复

点菜单时做执行如下代码.

private void jTableTestActionPerformed(java.awt.event.ActionEvent evt) \{

JInternalFrame\[\] frames = this.jDesktop1.getAllFrames();

boolean isExisted = false;

for (int i = 0; i < frames.length; ++i) \{

if (frames\[i\] instanceof NewJInternalFrame) \{

(this.jDesktop1.getDesktopManager()).activateFrame((frames\[i\]));

isExisted = true;

break;

\} \}

if (!isExisted) \{

NewJInternalFrame d = new NewJInternalFrame();

jDesktop1.add(d, javax.swing.JLayeredPane.DEFAULT\_LAYER);

d.setVisible(true);

3.给MDI窗体加滚动条

首先继承JDesktopPane，做一个JDesktop.代码如下。

在Frame上放一个JScrollPane,在JScrollPane上放上刚做的JDesktop

public class JDesktop extends JDesktopPane

public @Override void paint(Graphics g)

super.paint(g);

Dimension d = preferredSizeOfAllFrames();

this.setPreferredSize(d);

this.revalidate();

/\*\*

\* @return 返回最佳desktop尺寸..

\* 注：往左移时，尺寸没有变化，需改进。

\*/

public Dimension preferredSizeOfAllFrames()

JInternalFrame \[\] array = getAllFrames();

int maxX = 0;

int maxY = 0;

for (int i = 0; i < array.length; i++)

if ( array\[ i \].isVisible() )

int cx;

cx = array\[i\].getX();

int x = cx + array\[i\].getWidth();

if (x > maxX) maxX = x;

int cy;

cy = array\[i\].getY();

int y = cy + array\[i\].getHeight();

if (y > maxY) maxY = y;

return new Dimension(maxX, maxY);

5.使Frame屏幕居中

public MainFrame() \{

initComponents();

//以下是netbeans生成的代码

setLocationRelativeTo(null); //只需加这一句

6.设置启动窗体

只需新增一个独立类，这个类只需有以下一个方法.

public class Main \{

public static void main(String args\[\]) \{

java.awt.EventQueue.invokeLater(new Runnable() \{

public void run() \{

new MainFrame().setVisible(true);//这句设置第一个显示窗体

\});

7.制作PictureBox

直接用label

8.设计登录窗体

将登录窗体设为启动窗体(参考6)，点登录按钮时，执行如下代码.

private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) \{

if(!this.txtUserNo.getText().equals(""))

this.dispose();//这个函数好像已过时了。

new MainFrame().setVisible(true);

else

JOptionPane.showMessageDialog(this, "对不起!用户名不能为空.", "错误提示", JOptionPane.ERROR\_MESSAGE);

9.添加事件  
class TableSelectionFrame extends JFrame implements MouseListener \{  
private DefaultTableModel model;

private JTable table;

public TableSelectionFrame() \{  
setTitle("TableSelectionTest");  
setSize(300, 200);  
addWindowListener(new WindowAdapter() \{  
public void windowClosing(WindowEvent e) \{  
System.exit(0);  
\}  
\});

model = new DefaultTableModel(10, 10);

for (int i = 0; i < model.getRowCount(); i++)  
for (int j = 0; j < model.getColumnCount(); j++)  
model.setValueAt(new Integer((i + 1) \* (j + 1)), i, j);

table = new JTable(model);

table.addMouseListener(this);

Container contentPane = getContentPane();  
contentPane.add(new JScrollPane(table), "Center");

table.setCellSelectionEnabled(true);  
\}

public void mouseClicked(MouseEvent e) \{  
int row = table.getSelectedRow();  
int column = table.getSelectedColumn();  
System.out.println(model.getValueAt(row, column));  
\}

public void mouseEntered(MouseEvent e) \{  
\}

public void mouseExited(MouseEvent e) \{  
\}

public void mousePressed(MouseEvent e) \{  
\}

public void mouseReleased(MouseEvent e) \{  
\}  
\}

10.反射生成子窗口  
步骤１：  
private void showInternalFrame(String\[\] args) \{  
JInternalFrame\[\] frames = this.jDesktop1.getAllFrames();  
boolean isExisted = false;  
for (int i = 0; i < frames.length; ++i) \{  
if (frames\[i\].getClass().getName().equals(args\[0\])) \{  
(this.jDesktop1.getDesktopManager()).activateFrame((frames\[i\]));  
isExisted = true;  
break;  
\}  
\}  
if (!isExisted) \{  
try \{  
Class classDefinition = Class.forName(args\[0\]);  
Object obj = classDefinition.newInstance();  
jDesktop1.add((JInternalFrame) obj, javax.swing.JLayeredPane.DEFAULT\_LAYER);  
((JInternalFrame) obj).setVisible(true);  
\} catch (InstantiationException ex) \{  
Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);  
\} catch (IllegalAccessException ex) \{  
Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);  
\} catch (ClassNotFoundException ex) \{  
Logger.getLogger(MainFrame.class.getName()).log(Level.SEVERE, null, ex);  
\}  
\}

\}  
步骤２：调用  
showInternalFrame(new String\[\]\{"javaapplication1.DefineEditor"\});