JFrame,JPanel默认哪些布局？_course

JFrame,JPanel默认哪些布局？

为什么我的JFrame已经设置布局了，下面设置却会报错_course

public class CreatChat { private static JFrame jf = new JFrame(); /** * */ public CreatChat(){ CreatPanel creatPanel = new CreatPanel(); jf.setSize(426, 300); jf.setLocationRelativeTo(null); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jf.setUndecorated(true); jf.setResizable(false); BorderLayout border_layout = new BorderLayout(); jf.setLayout(border_layout); JPanel panel1 = creatPanel.CreateNorthPanel(jf); jf.add(panel1,BorderLayout.PAGE_START); JPanel panel2 = creatPanel.CrateCenterPanel(jf); jf.add(panel2,BorderLayout.CENTER); JPanel panel3 = creatPanel.CreateWestPanel(jf); jf.add(panel3,BorderLayout.LINE_START); JPanel panel4 = creatPanel.CrateSouthPanel(jf); jf.add(panel4,BorderLayout.PAGE_END); JPanel panel5 = creatPanel.CrateEastPanel(jf); jf.add(panel5,BorderLayout.LINE_END); jf.setVisible(true); } } public class CreatPanel { /** * */ private static final long serialVersionUID = -9049626153916559813L; private static LoginListener ll = null; public static JPanel CreateNorthPanel(final JFrame jf){ JPanel panel = new JPanel(); panel.setLayout(null); panel.setPreferredSize(new Dimension()); ImageIcon image = new ImageIcon("images/back.jpg"); JLabel background = new JLabel(image); background.setBounds(0, 0, 426, image.getIconHeight()); panel.add(background); JButton out = new JButton(new ImageIcon("images/close_normal.jpg")); out.setBounds(403, 0, 26, 26); out.setRolloverIcon(new ImageIcon("images/close_hover.jpg")); out.setBorderPainted(false); out.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub jf.dispose(); } }); panel.add(out); return panel; } public static JPanel CreateWestPanel(){ JPanel panel = new JPanel(); panel.setLayout(null); panel.setPreferredSize(new Dimension(130,0)); ImageIcon image = new ImageIcon("images/qq.jpg"); JLabel background = new JLabel(image); background.setBounds(0, 0, 120, 110); panel.add(background); return panel; } public static JPanel CrateCenterPanel(JFrame jf){ JPanel panel = new JPanel(); String str[] = {"123456789","456789123","789456123"}; JComboBox jcoCenter = new JComboBox(str);//为什么不能使用JComboBox<Object> panel.add(jcoCenter); jcoCenter.setEditable(true); jcoCenter.setBounds(0, 15, 175, 30); jcoCenter.setFont(new Font("Calibri",0,13)); JPasswordField jpaCenter = new JPasswordField(); jpaCenter.setLayout(new FlowLayout(FlowLayout.RIGHT,0,0)); jpaCenter.setBounds(0, 44, 175, 30); jpaCenter.setPreferredSize(new Dimension(185,25)); panel.add(jpaCenter); ImageIcon image = new ImageIcon("image/keyboard.jgp"); JButton jbu = new JButton(image); jbu.setPreferredSize(new Dimension(22,20)); jbu.setBorderPainted(false); jpaCenter.add(jbu); JCheckBox jch1 = new JCheckBox("记住密码"); jch1.setFocusPainted(false); jch1.setFont(new Font("宋体",0,13)); jch1.setBounds(0, 85, 80, 20); panel.add(jch1); JCheckBox jch2 = new JCheckBox("自动登录"); jch2.setFocusPainted(false); jch2.setFont(new Font("宋体",0,12)); jch2.setBounds(100, 85, 80, 20); ll = new LoginListener(jcoCenter, jpaCenter, jf); panel.add(jch2); return panel; } public static JPanel CrateEastPanel(){ JPanel panel = new JPanel(); panel.setLayout(null); panel.setPreferredSize(new Dimension(100,0)); JLabel regeist = new JLabel("注册账号"); regeist.setForeground(new Color(100,149,238)); regeist.setBounds(0, 13, 60, 30); regeist.setFont(new Font("宋体",0,12)); JLabel regetpwd = new JLabel("找回密码"); regetpwd.setForeground(new Color(100,149,238)); regetpwd.setBounds(0, 13, 60, 30); regetpwd.setFont(new Font("宋体",0,12)); panel.add(regetpwd); panel.add(regeist); return panel; } public static JPanel CrateSouthPanel(){ JPanel panel = new JPanel(); panel.setPreferredSize(new Dimension(0,51)); panel.setLayout(null); JButton jble = new JButton(new ImageIcon("images/single_normal.jgp")); jble.setPreferredSize(new Dimension(40,40)); jble.setFocusPainted(false); jble.setRolloverIcon(new ImageIcon("images/single_down.jpg")); jble.setBorderPainted(false); jble.setContentAreaFilled(false); jble.setBounds(0, 10, 40, 40); jble.setToolTipText("多账号登录"); ImageIcon image = new ImageIcon("images/login_normal.jpg"); JButton jb = new JButton("登 录",image); jb.setFont(new Font("宋体",0,13)); jb.setBounds(130, 0, 175, 40); jb.setHorizontalTextPosition(SwingConstants.CENTER); jb.setFocusPainted(false); jb.setContentAreaFilled(false); jb.setBorderPainted(false); jb.setRolloverIcon(new ImageIcon("images/login_hover.jpg")); jb.addActionListener(ll); JButton jbri = new JButton(new ImageIcon("images/right_normal.jpg")); jbri.setBounds(380, 10, 40, 40); jbri.setFocusPainted(false); jbri.setBorderPainted(false); jbri.setContentAreaFilled(false); jbri.setRolloverIcon(new ImageIcon("images/right_hover.jpg")); jbri.setToolTipText("二维码登录"); panel.add(jble); panel.add(jb); panel.add(jbri); panel.add(panel); return panel; } } 为什么我的JFrame已经设置布局了，下面设置却会报错

eclipse中new- other找不到JFrame_course

在代码中可以正常import swing，但是新建other中找不到JFrame，这是怎么回事，怎样解决？

java swing 布局，设置jpanel大小，位置_course

jpanel.setsize。。。这个为什么不生效？总是布满整个窗口，我只想一小块在中间。 注意：这个方法如果不行，有别的方法吗？ 绝对布局除外

JFrame布局学习_course

public void ManageView(){ jf.setVisible(false); JFrame jframe=new JFrame("超市购物管理"); JMenuBar jmb=new

java中的Jframe到底是怎么布局的？_course

起因：主要想实现一个注册界面。 问题：使用JFrame生成窗口，为什么在这同一个窗口(Frame)下添加一个按钮(Button)后原来的面板panel不见了？就是只能添加两个panel，之后再添加其它

SWING技术如何实现从JFrame窗口跳转到另一个JFrame窗口_course

比如用户登录界面登录成功了要转到新的用户界面 如何实现 原先的JFrame里面要写什么方法么还是直接new出新的JFrame？ 旧窗口是不是要用什么方法把窗口隐藏起来还是摧毁窗口此类的方法？

JAVA的Jframe图标怎么修改_course

 试了好多种办法图标这两个替换不掉，代码如下 ``` package demo; import java.awt.BorderLayout; import java.awt.EventQueue; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.border.EmptyBorder; import java.awt.Toolkit; public class test2 extends JFrame { private JPanel contentPane; /** * Launch the application. */ public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { try { test2 frame = new test2(); frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } /** * Create the frame. */ public test2() { setIconImage(Toolkit.getDefaultToolkit().getImage("C:\\Users\\yyj\\Desktop\\testPostOrder\\lib\\icon.jpg")); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setBounds(100, 100, 450, 300); contentPane = new JPanel(); contentPane.setBorder(new EmptyBorder(5, 5, 5, 5)); contentPane.setLayout(new BorderLayout(0, 0)); setContentPane(contentPane); } } ```

JPanel中添加组件覆盖问题_course

JPanel中添加组件，空布局，默认是先添加的显示层次比后添加的前。这个层次不可以不额外添加面板修改吗？

关于Java中JFrame继承的问题_course

如图，想问一下，为何我这里this无法调用setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

Java JFrame 使用 paint 方法不显示绘制图像。_course

``` public class Show extends JFrame{ public Show(){ setTitle("Calcutor"); setSize(90*3,160*3); setVisible(true); } } public class Main { public static void main(String args[]){ Show show=new Show(); Graphics g= show.getGraphics(); g.setColor(Color.pink); g.fillRect(0, 0, show.getWidth(), show.getHeight()); } } ``` 上面这个不能显示图片。 ``` public class Main { public static void main(String args[]){ Show show=new Show(); Graphics g= show.getGraphics(); try { Thread.currentThread().sleep(1000);//毫秒 } catch(Exception e){} g.setColor(Color.pink); g.fillRect(0, 0, show.getWidth(), show.getHeight()); } } ``` 当我加上 ``` try { Thread.currentThread().sleep(1000);//毫秒 } catch(Exception e){}； ``` 时就会显示图像，这是怎么回事？能不能 不加这个也能显示图像呢？

Swing中JFrame的刷新问题？_course

看API介绍的时候JFrame好像已经实现了双缓冲，但我调用repaint()的时候，原来存在的填充不会刷新掉，还保留在原来的位置上，一般的Frame我重写一个update()方法实现双缓冲就能把旧的

java JPanel布局_course

请教大家一个问题啊，我在一个JFrame的contentpane上面直接加了几个JButton,然后又想加一个JPanel，设置了JPanel透明，有什么办法或者JPanel加到什么地方能够让他覆盖掉

GUI里一个JFrame如何调用另一个JFrame？？_course

我写了个MainMenu的JFrame界面，里面在处理事件响应时要能调用另一个JFrame界面或Applet界面，但不知为啥原来MainMenu里的部分组建还显示？？ 部分代码如下： public v

请教JFrame和Frame的区别_course

比如我想做一个小动画，让球在移动。用paint和线程，不断重画，然后我发现用Frame可以成功实现。但是用JFrame却会出现出现新的球，原来的球还在，即可以看到几个球。。这是为什么

关于JFrame 组件布局 里面的坐标怎么确定啊_course

就是用坐标 布局 怎么确定位置呢 有什么工具吗

JAVA中画的图形不能显示，想知道问题出在哪？_course

package ObjectPrinciple; import java.awt.EventQueue; import javax.swing.ButtonGroup; import javax.swing.JFrame; import javax.swing.JToolBar; import java.awt.BorderLayout; import java.awt.Button; import javax.swing.JPanel; import javax.swing.JRadioButton; import java.awt.event.ItemListener; import java.awt.event.ItemEvent; import javax.swing.JPanel; import javax.swing.JSplitPane; import javax.swing.JList; public class DrawingBroad implements ItemListener{ private JFrame frame; private Canvas canvas; /** * Launch the application. */ public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { try { DrawingBroad window = new DrawingBroad(); window.frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } public void itemStateChanged(ItemEvent e) { JRadioButton rdb; rdb=(JRadioButton) e.getSource();//把获得的来源转换成单选按钮的类型 //强制转换 事件是由哪个对象发出来的 if(rdb.isSelected())//保证其中有一个按钮是被选中的 { if (rdb.getText()=="Lines") {//也就是按钮的名称，做到匹配 canvas.setTodoAction(0);//在中做得事件进行编号 } else if (rdb.getText()=="rectangle") { canvas.setTodoAction(1); } else if (rdb.getText()=="circle") { canvas.setTodoAction(2); }//可以在此添加代码，新按钮 else if (rdb.getText()=="move") { canvas.setTodoAction(100); } } } /** * Create the application. */ public DrawingBroad() {//构造函数， initialize(); } /** * Initialize the contents of the frame. */ private void initialize() { frame = new JFrame(); frame.setBounds(100, 100, 800, 600); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JSplitPane splitPane = new JSplitPane(); splitPane.setDividerLocation(160); frame.getContentPane().add(splitPane, BorderLayout.CENTER); canvas= new Canvas(); splitPane.setRightComponent(canvas); JList<String> list = new JList<String>(); splitPane.setLeftComponent(list); canvas.setLayers(list); JToolBar toolBar = new JToolBar(); frame.getContentPane().add(toolBar, BorderLayout.NORTH); JRadioButton rdbtnLines = new JRadioButton("lines"); rdbtnLines.setSelected(true);//首先选择一个按钮 rdbtnLines.addItemListener(this); toolBar.add(rdbtnLines); JRadioButton rdbtnRectangle = new JRadioButton("rectangle"); rdbtnRectangle.addItemListener(this); toolBar.add(rdbtnRectangle); JRadioButton rdbtnMove = new JRadioButton("move"); rdbtnMove.addItemListener(this); toolBar.add(rdbtnMove); JRadioButton rdbtnCircle = new JRadioButton("circle"); rdbtnCircle.addItemListener(this); toolBar.add(rdbtnCircle); ButtonGroup bg=new ButtonGroup(); bg.add(rdbtnLines); bg.add(rdbtnRectangle); bg.add(rdbtnMove); bg.add(rdbtnCircle); } } package ObjectPrinciple; import java.awt.Color; import java.awt.Graphics; import java.awt.Point; import java.awt.Rectangle; import java.awt.event.MouseEvent; import java.util.ArrayList; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.event.MouseInputAdapter; import javax.swing.event.MouseInputListener; public class Canvas extends JPanel { private int todoAction; private Rectangle scope; private ArrayList<Shape> shapes; private JList<String > layers; public void setLayers(JList<String> layers) { this.layers = layers; } public void setTodoAction(int todoAction) { this.todoAction = todoAction; } public Canvas() { shapes= new ArrayList<Shape>(); addMouseMotionListener(mouseHandler); addMouseListener(mouseHandler); } public void paintShape(Shape s) { // TODO Auto-generated method stub shapes.add(s); String[] strings = new String[shapes.size()]; int i=0; for (Shape shape:shapes) { strings[i++]=shape.toString(); } layers.setListData(strings); repaint(); } private MouseInputListener mouseHandler = new MouseInputAdapter() { Point startPoint; @Override public void mousePressed(MouseEvent e) { // TODO Auto-generated method stub //初始化 startPoint = e.getPoint(); scope = new Rectangle(); } @Override public void mouseReleased(MouseEvent e) { // TODO Auto-generated method stub //消除矩形框 if(todoAction==100) { Moving m = shapes.get(layers.getSelectedIndex()); m.move(e.getPoint().x, e.getPoint().y); scope = null; repaint(); } else { setScope(startPoint,e.getPoint()); if(scope.width > 0||scope.height>0) if(todoAction==0) { MyLine line = new MyLine(); line.setShape(scope.x, scope.y, scope.width, scope.height, 0, "line"); paintShape(line); }else if(todoAction == 1) { MyRectangle rectangle = new MyRectangle(); rectangle.setShape(scope.x, scope.y, scope.width, scope.height, 1, "rectangle"); paintShape(rectangle); }else if (todoAction == 2) { Circle circle= new Circle(); circle.setShape(scope.x, scope.y, scope.width, scope.height, 2, "circle"); paintShape(circle); } scope=null; repaint(); } } @Override public void mouseDragged(MouseEvent e) { // TODO Auto-generated method stub if(scope==null) { setScope(startPoint, e.getPoint()); } repaint(); } private void setScope(Point starPoint,Point endPoint) { int x=Math.min(startPoint.x, endPoint.x); int y=Math.min(startPoint.y, endPoint.y); int w=Math.abs(startPoint.x - endPoint.x); int h=Math.abs(startPoint.y - endPoint.y); scope.setBounds(x,y,w,h); } }; @Override public void print(Graphics g) { // TODO Auto-generated method stub super.print(g); g.setColor(Color.BLACK); if(scope != null) g.drawRect(scope.x, scope.y, scope.width,scope.height); //需要一个队列，需要把画的图形加到队列，调用每个元素的drawingshape方法 for(Drawing d:shapes) { d.drawingShape(g); } } } package ObjectPrinciple; import java.awt.Graphics; public interface Drawing { public void drawingShape(Graphics g); } package ObjectPrinciple; public interface Moving { public void move(int x,int y); } package ObjectPrinciple; public abstract class Shape implements Drawing,Moving{ //位置 int x,y; //宽度，高度 int width,height; int shapetype; String shapename; public void setShape(int x, int y, int width, int height, int shapetype, String shapename) { //super(); this.x = x; this.y = y; this.width = width; this.height = height; this.shapetype = shapetype; this.shapename = shapename; } @Override public void move(int x, int y) { // TODO Auto-generated method stub this.x = x; this.y = y; } @Override public String toString() { return shapename; } } package ObjectPrinciple; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.geom.Line2D; public class MyLine extends Shape { public void drawingShape(Graphics g) { Graphics2D g2d=(Graphics2D) g; Line2D line2d = new Line2D.Double(x,y,x+width,y+height); g2d.draw(line2d); } } package ObjectPrinciple; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import java.awt.geom.Line2D; import java.awt.geom.Rectangle2D; public class MyRectangle extends Shape { @Override public void drawingShape(Graphics g) { // TODO Auto-generated method stub Graphics2D g2d=(Graphics2D) g; //Rectangle2D rect = new Line2D Rectangle2D rect = new Rectangle2D.Double(x,y,x+width,y+height); g2d.draw(rect); } }