默认情况下，在swing中选择文本

Question

当JTextField事件发生时，默认情况下会自动选择JTextArea和focusGained中的文字吗？

Answer 1

你刚刚说了怎么做 - FocusGistener的focusGained事件。

然后，您可以通过FocusEvent的getSource()方法获取焦点已获得的JComponent，然后在其上调用selectAll()方法。

类似的东西：

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();

更多信息如下：

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

这样的东西

    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);
            }
        });
    }
}