GUI树组件，表格

GUI树组件，表格

树组件首先要new一个JTree，再加结点，然后添加到 JScrollPane

JTree tree1=new JTree();

//.......添加节点

add(new ScrollPane(tree1)

添加节点

DefaultMutableTreeNode root=new DefaultMutableTreeNode("dongxi")//后面的是备注

DefaultMutableTreeNode root=new DefaultMutableTreeNode(new Good("aa",11));//还可以作为叶子new 对象

添加监视器（由树来添加

addTreeSelectionListener(TreeSelectionListener listener)

TreeSelectionListener接口的方法

public void valueChanged(TreeSelectionEvent e)

在上面的接口方法中，返回树的结点，再返回结点中的对象

DefaultMutableTreeNode node1=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();//只有树Tree才能用的方法

if(node.isLeaf())//判断是否叶子节点

Obeject a=(Obeject)node.getUserObject()//返回叶子里面的对象

完整的测试代码

public class test{

    public static void main(String args[]){

        MyWin window1=new MyWin();

        window1.setBounds(12,12,400,300);

    }

}

class MyWin extends JFrame implements TreeSelectionListener{

    JTextField text1;

    JButton button1,button2;

    JTextArea textArea1,textArea2;

    JLabel label1;

    JTree tree1;

    MyWin(){

        init();

        setVisible(true);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    void init(){

        DefaultMutableTreeNode root=new DefaultMutableTreeNode("Goods");

        DefaultMutableTreeNode nodeTV=new DefaultMutableTreeNode("TV");

        DefaultMutableTreeNode nodePhone=new DefaultMutableTreeNode("phone");

        DefaultMutableTreeNode tv1=new DefaultMutableTreeNode(new Goods("huangTV",11));

        DefaultMutableTreeNode tv2=new DefaultMutableTreeNode(new Goods("yuTV",21));

        DefaultMutableTreeNode phone1=new DefaultMutableTreeNode(new Goods("ga",31));

        DefaultMutableTreeNode phone2=new DefaultMutableTreeNode(new Goods("bing",11));

        root.add(nodeTV);

        root.add(nodePhone);

        nodeTV.add(tv1);

        nodeTV.add(tv2);

        nodePhone.add(phone1);

        nodePhone.add(phone2);

        tree1=new JTree(root);

        tree1.addTreeSelectionListener(this);

        setLayout(new GridLayout(1,2));

        add(new JScrollPane(tree1));

        textArea2=new JTextArea(15,15);

        add(new JScrollPane(textArea2));

    }

    public void valueChanged(TreeSelectionEvent e){

        DefaultMutableTreeNode a=(DefaultMutableTreeNode)tree1.getLastSelectedPathComponent();

        if(a.isLeaf()){//是叶子节点？

            Goods b=(Goods)a.getUserObject();

            textArea2.append(b.name+": "+b.price+"\n");

        }

        else

            textArea2.setText(null);

    }

}

class Goods{

    String name;

    double price;

    Goods(String name,double price){

        this.name=name;

        this.price=price;

    }

}

---

表格组件

Jtable默认的构造方法有7个，这里说常用的3个

JTable()

JTable(int a,int b)//几行几列

JTable(Object data[][],Object columnName[])//data为数据数组，columnName为列名数组

如果表格data[][]是 数字类型，可以用 Double.parseDouble 或者Integer.parseInt(s);

调用repaint来刷新表格

计算成绩代码测试

class MyWin extends JFrame implements ActionListener{

    JTable table1;

    JButton button1;

    Object a[][];

    Object name[]={"姓名","英语成绩","数学成绩","总成绩"};

    MyWin(){

        init();

        setVisible(true);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }

    void init(){

        a=new Object[8][4];

        for(int i=0;i<8;i++){

            for(int j=0;j<4;j++){

                if(j!=0)

                    a[i][j]=0;

                else

                    a[i][j]="姓名";

            }

        }

        button1=new JButton("click");

        table1=new JTable(a,name);

        Container con1=this.getContentPane();//获得一个容器,不用add

        getContentPane().add(new JScrollPane(table1), BorderLayout.CENTER);

        con1.add(new JLabel("update the data and click the button"),BorderLayout.NORTH);

        con1.add(button1,BorderLayout.SOUTH);

        button1.addActionListener(this);

//        validate();//验证组件

    }

    public void actionPerformed(ActionEvent e) {

        double sum=0;

        boolean boo=true;

        for(int i=0;i<8;i++){

            sum=0;

            for(int j=1;j<3;j++){

                try{sum+=Double.parseDouble(a[i][j].toString());

                }

                catch(Exception ee){

                    boo=false;

                    table1.repaint();

                }

            }

            if(boo==true){

                a[i][3]=sum+"";//把他改为String

                table1.repaint();

            }

        }

    }

}