java - swing默认选择文本

Question

默认情况下，有什么方法可以在事件发生时JTextField自动选择文本？JTextAreafocusGained

Answer 1

你刚刚说了怎么做——一个 FocusListener 的 focusGained 事件。

然后，您可以通过 FocusEvent 的方法获取其焦点已获得的 JComponent，然后在其上getSource()调用该selectAll()方法。

就像是：

FocusAdapter selectAllFocusAdapter = new FocusAdapter() {
  public void focusGained(FocusEvent e) {
    final JTextComponent tComponent = (JTextComponent) e.getSource();
    SwingUtilities.invokeLater(new Runnable() {

      @Override
      public void run() {
        tComponent.selectAll();
      }
    });
    tComponent.selectAll();
  }
};

myJTextField.addFocusListener(selectAllFocusAdapter);
otherJTextField.addFocusListener(selectAllFocusAdapter);
myTextArea.addFocusListener(selectAllFocusAdapter);

Answer 2

这就是你需要的：

jTextField1.selectAll();

更多内容如下：

jTextField1.addFocusListener(new FocusListener() {

        @Override
        public void focusGained(FocusEvent e) {
            if(jTextField1.getText().equals(initialText))
                //jTextField1.setText("");
                jTextField1.selectAll();
        }

        @Override
        public void focusLost(FocusEvent e) {
            if(jTextField1.getText().equals(""))
                jTextField1.setText("whatever");
        }
    });

Answer 3

你期待像

    class MyFocusTextField extends JTextField {
    {
        addFocusListener(new FocusListener() {

            @Override
            public void focusGained(FocusEvent e) {
                FocusTextField.this.select(0, getText().length());
            }

            @Override
            public void focusLost(FocusEvent e) {
                FocusTextField.this.select(0, 0);
            }
        });
    }
}