Question

我的JTable有一个密码字段编辑器。我想在用户单击编辑另一个字段时，如果文本长度小于8位，则显示错误消息。我尝试过焦点听众。但它不起作用。请帮助我，因为我刚刚开始使用java swing。

class PasswordEditor extends DefaultCellEditor 
{

    TextBox m_passWord = new TextBox(); 
    public PasswordEditor() {
        super(new TextBox());
    }

    @Override
    public Object getCellEditorValue() {

        return this.m_passWord.getText();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {

        Object fieldValue = value;
        if(null == fieldValue)
            fieldValue = Constants.EMPTY_STRING;

        this.m_passWord.addInputMethodListener(new InputMethodListener() {

            @Override
            public void inputMethodTextChanged(InputMethodEvent event)
            {
                // TODO Auto-generated method stub

            }

            @Override
            public void caretPositionChanged(InputMethodEvent event)
            {
                // TODO Auto-generated method stub

            }
        })
        this.m_passWord.addFocusListener(new FocusListener() {

            @Override
            public void focusLost(FocusEvent e)
            {
                if (!e.isTemporary()) {
                      String content = PasswordEditor.this.m_passWord.getText();
                      System.out.println((content));
                }

            }

            @Override
            public void focusGained(FocusEvent e)
            {
                //TODO init
            }
        });

        this.m_passWord.setEditable(true);
        this.m_passWord.setText(fieldValue.toString());
        return this.m_passWord;
    }


}

Answer 1

正如我理解这个问题，它是关于验证编辑器中的输入（保护自身免受无效值的模型是另一个故事，IMO）并在s /时通知用户他/她的错误他试图提交意见。

这样做的一个简单方法是使用InputVerifier：

在其验证方法中实施验证规则
在其shouldYieldFocus
子类DefaultCellEditor并覆盖其stopCellEditing以调用shouldYieldFocus并返回其结果（又名：拒绝提交编辑）

一些代码段：

final InputVerifier iv = new InputVerifier() {

    @Override
    public boolean verify(JComponent input) {
        JTextField field = (JTextField) input;
        return field.getText().length() > 8;
    }

    @Override
    public boolean shouldYieldFocus(JComponent input) {
        boolean valid = verify(input);
        if (!valid) {
            JOptionPane.showMessageDialog(null, "invalid");
        }
        return valid;
    }

};
DefaultCellEditor editor = new DefaultCellEditor(new JTextField()) {
    {
        getComponent().setInputVerifier(iv);
    }

    @Override
    public boolean stopCellEditing() {
        if (!iv.shouldYieldFocus(getComponent())) return false;
        return super.stopCellEditing();
    }

    @Override
    public JTextField getComponent() {
        return (JTextField) super.getComponent();
    }

};

JTable table = new JTable(10, 2);
table.setDefaultEditor(Object.class, editor);

Answer 2

覆盖stopCellEditing（）并在其中实现条件。

 class PasswordEditor extends DefaultCellEditor 
{

    TextBox m_passWord = new TextBox(); 
    public PasswordEditor() {
        super(new TextBox());
    }

            @Override
    public boolean stopCellEditing()
    {
        if(getCellEditorValue().toString().length() < 8)
        {
            JOptionPane.showMessageDialog(UsmUserView.this.m_Parent, "Password Must Be 8 Bytes Long !! Please Check");
            return false;
        }
        fireEditingStopped();
        return true;
    }

    @Override
    public Object getCellEditorValue() {

        return this.m_passWord.getText();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {

        Object fieldValue = value;
        if(null == fieldValue)
            fieldValue = Constants.EMPTY_STRING;

        this.m_passWord.setEditable(true);
        this.m_passWord.setText(fieldValue.toString());
        return this.m_passWord;
    }


}

Answer 3

覆盖stopCellEditing（），你可以尝试以下代码来获取错误单元的焦点。

class PasswordEditor extends DefaultCellEditor 
{

    private TextBox m_passWord = new TextBox(); 
    public PasswordEditor() {
        super(new TextBox());
    }

            @Override
    public boolean stopCellEditing()
    {
        if(getCellEditorValue().toString().length() < 8)
        {
            // Text box will get the focus and will shown in Red line as border for that cell.
            TextBox aTextBox = (TextBox)getComponent();
            aTextBox.setBorder(new LineBorder(Color.red));
            aTextBox.selectAll();
            aTextBox.requestFocusInWindow();
            JOptionPane.showMessageDialog(UsmUserView.this.m_Parent, "Password Must Be 8 Bytes Long !! Please Check");
            return false;
        }
        return super.stopCellEditing();
    }

    @Override
    public Object getCellEditorValue() {

        return this.m_passWord.getText();
    }

    @Override
    public Component getTableCellEditorComponent(JTable table,
            Object value, boolean isSelected, int row, int column) {

        Object fieldValue = value;
        if(null == fieldValue)
            fieldValue = Constants.EMPTY_STRING;

        this.m_passWord.setEditable(true);
        this.m_passWord.setText(fieldValue.toString());
        return this.m_passWord;
    }


}

使用编辑器验证表的单元格

3 个答案: