如何防止在JTable单元格中键入除数字以外的字符? [英] How to prevent typing characters except numbers in JTable cells?

问题描述

我正在一个项目中，我必须使用JTable从用户那里获取输入.在这里，我创建了一个JTable，它将仅包含数值.我在keyTyped上对其进行了验证，并且可以正常工作，直到按F2或单击该单元格为止.当我这样做时，它将光标放在单元格中，并且还键入了其他字符.

I am working in a project where I have to get input from user by using a JTable. Here I had created a JTable which will have only numerical values. I validated it on keyTyped and its working fine until I press F2 or click on the cell. When I am doing so, it put a cursor in cell and other characters are also being typed.

jtblValues.addKeyListener(new KeyListener() {
        public void keyPressed(KeyEvent e) {
            if (e.getKeyCode()==KeyEvent.VK_ENTER && (jtblValues.getRowCount() == (jtblValues.getSelectedRow()+1))) 
                model.addRow(new Object[]{"", "", ""}); 
            else if (e.getKeyCode()==KeyEvent.VK_TAB && (jtblValues.getRowCount() == (jtblValues.getSelectedRow()+1)) && (jtblValues.getColumnCount() == (jtblValues.getSelectedColumn()+1)))
                model.addRow(new Object[]{"", "", ""}); 
        }
        public void keyReleased(KeyEvent e) {}
        public void keyTyped(KeyEvent e) {
            char c = e.getKeyChar();
            if (!((c >= '0') && (c <= '9') || (c == KeyEvent.VK_BACK_SPACE) || (c == KeyEvent.VK_DELETE) || (c == KeyEvent.VK_ENTER) || (c == KeyEvent.VK_TAB))) {
                getToolkit().beep();
                e.consume();
            }
        } 
    } );

那么，如何通过键入数字以外的其他字符来阻止用户?

So, how to prevent user by typing other characters than numbers?

谢谢.

推荐答案

您可以通过提供适当的部分"rel =" nofollow noreferrer>如何使用表格教程.

You can achieve this by providing an appropriate TableCellEditor as described in Using an Editor to Validate User-Entered Text section of How to Use Tables tutorial.

关键是使用 JFormattedTextfield 使用 NumberFormatter 和 NumberFormat .例如:

The key is using a JFormattedTextfield as editor with NumberFormatter and NumberFormat. For instance:

NumberFormat integerFormat = NumberFormat.getIntegerInstance();
NumberFormatter formatter = new NumberFormatter(integerFormat);
formatter.setAllowsInvalid(false);
JFormattedTextField textfield = new JFormattedTextField(formatter);

请参见如何使用带格式的文本字段教程进一步的细节.

See How to Use Formatted Text Fields tutorial for further details.

使用Swing时，最好使用Keybinding而不是KeyListener，这是出于本主题中讨论的原因:键绑定与键监听器在Java中.请参考以KeyBinding开始的教程:如何使用键绑定

It's preferable use Keybinding over KeyListeners when you're working with Swing for the reasons discussed in this topic: Key bindings vs. key listeners in Java. Refer to the tutorial to start with KeyBinding: How to Use Key Bindings

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