java - getColumnName 无法正常工作

Question

我正在为 TableModel 使用一个新类，它扩展了 AbstractTableModel，但是当我尝试添加标题行时，它没有显示。这是代码:

 public class StudentTableModel extends AbstractTableModel {

    private ArrayList<Student> student;
    private ArrayList<Group> groups;
    private int tableType=2;
    public String []coluNamess = {
                                    "id","name",
                                    "last name",
                                    " birth date",
                                    "phone","adress",
                                    "class"
                                 };
    public String  []coluNamesg = {
                                    "id","title",
                                    "level","num"
                                  };

    public String getColumnName(int column ) {
        if(tableType==1) {
            return this.coluNamess[column];
        } else {
            return this.coluNamesg[column];
        } 
    }

    public int getColumnCount() {
        if(tableType==1) {
            return 7;
        } else {
            return 4;
        }
    }

    public int getRowCount() {
        if(tableType==1) { 
            return student.size();
        } else {
            return groups.size();
        }
    }

    public String getValueAt(int row, int colu) {
        if(tableType==1) {
            Student studentm=student.get(row);
            switch(colu) {
                case 0:
                    return  Double.toString((double)studentm.getId());
                case 1:
                    return studentm.getFname();
                case 2:
                    return studentm.getLname();
                case 3:
                    return studentm.getB_date();
                case 4:
                    return studentm.getPhone();
                case 5:
                    return studentm.getAdress();
                case 6:
                    return Double.toString((double)studentm.getGroupId());
            }
        } else if(tableType==2) {
            Group group=groups.get(row);
            switch(colu) {
                case 0:
                    return  Double.toString((double)group.getId());
                case 1:
                    return  group.getTitle();
                case 2:
                    return  group.getLevel();
                case 3:
                    return  Double.toString((double)group.getTime());
            }
        }  
        return null;
    }

    public void setStudent(ArrayList<Student> students) {
        this.student= students;
    }

    public void setGroup(ArrayList<Group> groups) {
        this.groups= groups;
    }

    public void setType(int type) {
        this.tableType=type;
    }
}

标题未出现，但显示内容。我不知道问题出在哪里!!!!

Answer 1

向滚动 Pane 添加一个表格，即:new JScrollPane(table)。请参阅Adding a Table to a Container了解更多详情:

The scroll pane automatically places the table header at the top of the viewport. The column names remain visible at the top of the viewing area when the table data is scrolled.

If you are using a table without a scroll pane, then you must get the table header component and place it yourself.