JTable输入验证器 [英] JTable Input Verifier

问题描述

我正在尝试为JTable创建一个简单的输入验证器. 最后，我重写了方法:editingStopped(). 问题在于该事件不包含有关已更新单元的信息.

I am trying to create a simple Input Verifier for a JTable. I ended up with overriding the method: editingStopped(). The problem is that the event does not include informations about the cell that has been updated.

这是我的伪代码":

  If (user finished editing a cell)  {
     Check if cell`s value is "1" or "0" or "-"  (Karnaugh-Veitch)
     If (check = false)
        setValue (cell, "");
   }

我第一次尝试的是这里:

The first I tried was this here:

table.getModel().addTableModelListener(new TableModelListener() {
            @Override
            public void tableChanged(TableModelEvent e) {
                inputVerify (e.getColumn(), e.getFirstRow());
            }
});

    public void inputVerify (int column, int row) {
        boolean verified = true;
        String field = table.getValueAt(row, column).toString();

        if (field != null && field.length() == 1) {
            if ( !(field.charAt(0) == '0' || field.charAt(0) == '1' || field.charAt(0) == '-' ))
                verified = false;
        }
        else {
            verified = false;
        }

        if (!verified) {
            table.getModel().setValueAt("", row, column);
            java.awt.Toolkit.getDefaultToolkit().beep();
        }

        System.out.println ("Column = " + column + " Row = " + row + " Value = " + table.getValueAt(row, column) +" Verified = "+verified);
    }

但是最终结果是:StackOverflow异常.我猜是问题所在:setValueAt(..)触发了另一个tableChanged()事件，并且正在生成一个无限循环.

But this ends up with an : StackOverflow Exception. I guess the problem is that: setValueAt(..) fires another tableChanged() event and an endless loop is being generated.

现在，我在这里尝试过

    table.getDefaultEditor(Object.class).addCellEditorListener(new CellEditorListener() {

        // called when editing stops
        public void editingStopped(ChangeEvent e) {

            // print out the value in the TableCellEditor
            System.out.println(((CellEditor) e.getSource()).getCellEditorValue().toString());

        }

        public void editingCanceled(ChangeEvent e) {
            // whatever
        }
    });

但是正如您所看到的，我只能获取单元格的新值，而不是坐标". 我需要调用:setValueAt(..)方法，但是我不知道如何获取单元格的坐标.

But as you can see I can just retrieve the new value of the cell, not the "coordinates". I need to call: setValueAt( .. ) method, but I dont know how to get the cell`s coordinates.

还是有一种更简单的方法来创建输入验证器?

Or is there a more simple way to create an input verifier??

最诚挚的问候 约阿尼斯·K.

Best regards Ioannis K.

推荐答案

首先:不完全支持JTable编辑的输入验证.一些评论

First: input validation on JTable editing is not well supported. A couple of comments

• TableModelListener中的tableChanged并不是进行验证的好地方，因为那时更改已经发生(模型将事实通知给其侦听器)
• 结果，无论您选择哪种验证(验证)方法挂钩，都永远不会回过头来讨论该模型，您最终将陷入无限循环(如您所见)
• 应用程序提供的CellEditorListeners相当无用，因为a)无法保证通知顺序(JTable可能尚未更新模型)b)编辑器的生命周期定义不明确

在所有这些(不完整的，不幸的是；-)不可以之后，有点希望:最好的选择是实现一个自定义CellEditor，它在stopCellCellEditing中进行验证:如果新值无效，则返回false并有选择地提供视觉错误反馈.查看JTable.GenericEditor，以了解如何实现

After all those (incomplete, unfortunately ;-) no-nos, a little hope: best bet is to implement a custom CellEditor which does the validation in stopCellCellEditing: if the new value isn't valid, return false and optionally provide a visual error feedback. Have a look at JTable.GenericEditor to get an idea of how that might be done

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