java - 每次按钮事件发生时从 JTable 中删除以前的内容

Question

我很难从 JTable 中删除数据。我尝试过 JTable .repaint()、setRowCount(0) 以及 model.removeRow()。我创建了 print 语句来查看使用 setRowCount 时的行数，行数确实变为 0，但我的表没有更新。这是我需要实现的该项目的最后一部分。我不确定为什么我的表没有更新，因为我正在使用 removeRow 和 setRowCount 更改模型。如果你们能引导我走向正确的方向，我将不胜感激。

public class TemplateGui extends JFrame  {
    private final ButtonGroup buttonGroup = new ButtonGroup();
    private JTextField textField;
    private static String [] sortedRoles_Flags,finalFlagsArr,finalHSArr;
    private static String finalFlags="",finalHS="",columnToConvert="Result";
    private Vector<String> SF,HS,column;
    private JTable hotelSecurityTable,securityFlagsTable;
    private DefaultTableModel hsTableModel,sfTableModel;


    public TemplateGui(){

        super("Galaxy Template Generator V1.0");
        //column name
        column = new Vector(Arrays.asList(columnToConvert));

        getContentPane().setForeground(new Color(0, 0, 0));
        getContentPane().setLayout(null);
        getContentPane().setBackground(new Color(51, 51, 51));

        //radio buttons
        JRadioButton rdbtnNewRadioButton = new JRadioButton("Central User ");
        rdbtnNewRadioButton.setFont(new Font("Tahoma", Font.BOLD, 11));
        rdbtnNewRadioButton.setBackground(Color.WHITE);
        buttonGroup.add(rdbtnNewRadioButton);
        rdbtnNewRadioButton.setBounds(222, 75, 127, 36);
        getContentPane().add(rdbtnNewRadioButton);

        final JRadioButton rdbtnPropertyUser = new JRadioButton("Property User");
        rdbtnPropertyUser.setFont(new Font("Tahoma", Font.BOLD, 11));
        rdbtnPropertyUser.setBackground(Color.WHITE);
        buttonGroup.add(rdbtnPropertyUser);
        rdbtnPropertyUser.setBounds(222, 38, 127, 34);
        getContentPane().add(rdbtnPropertyUser);

        textField = new JTextField();
        textField.setFont(new Font("Tahoma", Font.BOLD, 18));
        textField.setBounds(10, 35, 53, 34);
        getContentPane().add(textField);
        textField.setColumns(10);

        JLabel lblHotelSecurity = new JLabel("Hotel Security (H S)");
        lblHotelSecurity.setHorizontalAlignment(SwingConstants.CENTER);
        lblHotelSecurity.setFont(new Font("Tahoma", Font.BOLD, 13));
        lblHotelSecurity.setBounds(10, 144, 189, 23);
        lblHotelSecurity.setBackground(new Color(204, 204, 204));
        lblHotelSecurity.setOpaque(true);
        getContentPane().add(lblHotelSecurity);

        JLabel label = new JLabel("Security Flags (S F)");
        label.setHorizontalAlignment(SwingConstants.CENTER);
        label.setFont(new Font("Tahoma", Font.BOLD, 13));
        label.setBounds(222, 144, 372, 23);
        label.setBackground(new Color(204, 204, 204));
        label.setOpaque(true);
        getContentPane().add(label);

        JLabel lblEnterTemplateCode = new JLabel("ENTER TEMPLATE CODE");
        lblEnterTemplateCode.setForeground(new Color(255, 255, 255));
        lblEnterTemplateCode.setFont(new Font("Tahoma", Font.BOLD, 14));
        lblEnterTemplateCode.setBounds(10, 9, 175, 23);
        getContentPane().add(lblEnterTemplateCode);

        JLabel lblSelectUserRole = new JLabel("SELECT USER ROLE LEVEL");
        lblSelectUserRole.setForeground(new Color(255, 255, 255));
        lblSelectUserRole.setFont(new Font("Tahoma", Font.BOLD, 14));
        lblSelectUserRole.setBounds(222, 13, 195, 14);
        getContentPane().add(lblSelectUserRole);

        //Submit button action
        Button button = new Button("Generate Template");
        button.setFont(new Font("Dialog", Font.BOLD, 12));
        button.setBackground(new Color(102, 255, 102));
        button.setForeground(Color.BLACK);
        button.setBounds(467, 83, 127, 41);
        getContentPane().add(button);


        button.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent arg0) {

                Query excell = new Query();
                //get template text
                String template = textField.getText().toUpperCase();
                System.out.println(template);

                if(rdbtnPropertyUser.isSelected()){
                    try {
                    //property user was selected
                        excell.runProcess(1);
                        System.out.println("you selected Property user");
                    } catch (IOException e) {

                        e.printStackTrace();
                    }
                }
                else{
                    try {
                    //Central User was selected 
                        excell.runProcess(2);
                        System.out.println("you selected central user");
                    } catch (IOException e) {

                        e.printStackTrace();
                    }
                }

                System.out.println("NOW WERE HERE");
                //get static variables from Excel Query 
                for(int i = 0; i< Query.sortedGF.length; i++)
                {
                    if(Query.sortedGF[i].contains(template)){
                         sortedRoles_Flags  =Query.sortedGF[i].split(" ");
                         System.out.println("THIS RAN"+" :"+i); 
                         break;
                    }

                }

                //add data to table
                int j=1;
                int sizeOfFlags = Query.securityFlags.length;


                //Add HS to FinalHS Variable only if Yes
                for(int i=0;i< sortedRoles_Flags.length+1-sizeOfFlags;i++)
                {
                    if(sortedRoles_Flags[i].matches("Y|y|Y\\?|\\?Y|y\\?|\\?y"))
                        {
                            System.out.println("Hotel security:"+" "+sortedRoles_Flags[i]+" HS Added: "+Query.hotelSecurity[i]);
                            finalHS += Query.hotelSecurity[i]+"+";
                            System.out.println("Hotel security:"+" "+finalHS);
                        }
                }

                //add Security Flags to Final Flags
                for(int i=(sortedRoles_Flags.length-sizeOfFlags+1);i< sortedRoles_Flags.length;i++)
                {                   
                        finalFlags += Query.securityFlags[j]+"\t\t: "+ sortedRoles_Flags[i]+" + ";
                        j++;
                }

                //Leave open just incase they would prefer a text file for template in which case we just write it
                System.out.println(finalFlags);

                System.out.println(finalHS);

                //Convert to String Arrays in order to add to our JTable
                finalFlagsArr= finalFlags.split("\\+");
                finalHSArr = finalHS.split("\\+");

                for(int i=0; i <finalHSArr.length;i++)
                    finalHSArr[i].replaceAll(" ","");

                hsTableModel.setRowCount(0);
                for (String row : finalHSArr) {
                    hsTableModel.addRow(new Object[]{row});
                }
                sfTableModel.setRowCount(0);
                for (String row : finalFlagsArr) {
                    sfTableModel.addRow(new Object[]{row});
                }

            }
        });
        //scroll panes for flags
        JScrollPane scrollPaneHS = new JScrollPane();
        scrollPaneHS.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
        scrollPaneHS.setBounds(10, 170, 189, 185);
        getContentPane().add(scrollPaneHS);

        JScrollPane scrollPaneSF = new JScrollPane();
        scrollPaneSF.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS);
        scrollPaneSF.setBounds(222, 170, 372, 187);
        getContentPane().add(scrollPaneSF);

        //tables for updates
        hsTableModel = new DefaultTableModel(HS,column);
        hotelSecurityTable = new JTable(hsTableModel);
        hotelSecurityTable.setBackground(new Color(255, 255, 255));
        scrollPaneHS.setViewportView(hotelSecurityTable);

        sfTableModel = new DefaultTableModel(SF,column);
        securityFlagsTable = new JTable(sfTableModel);
        scrollPaneSF.setViewportView(securityFlagsTable);


    }


}

更新我的最新尝试。这似乎有效，但第二次就不行了。

if(hsTableModel.getRowCount() !=0 && sfTableModel.getRowCount() !=0){
                    for(int i=0; i<hsTableModel.getRowCount();i++)
                        hsTableModel.removeRow(i);

                    for(int i=0; i<sfTableModel.getRowCount();i++)
                        sfTableModel.removeRow(i);

                    sfTableModel.fireTableRowsDeleted(0, sfTableModel.getRowCount()-1);
                    hsTableModel.fireTableRowsDeleted(0, hsTableModel.getRowCount()-1);
                }

Answer 1

when using setRowCount and the rows do become 0 however my table does not update.

由于您使用的是 DefaultTableModel，因此 setRowCount(0) 是用于清除所有条目的模型的正确方法。应该自动重新绘制自己。

创建一个简单的SSCCE这说明了你的问题。 SSCCE 应包含一个包含数据的 JTable，然后是一个用于调用 setRowCount() 方法的 JButton。

向自己证明基本概念有效，然后确定为什么您的实际代码不起作用。如果表没有重新绘制，则通常意味着您正在对尚未添加到 GUI 上可见的 JTable 的 TableModel 调用 setRowCount() 方法。

另外，不要:

1. 使用按钮。您应该使用 JButton
2. 使用空布局。 Swing 被设计为与布局管理器一起使用。