addFocusListener(FocusListener fl);class fl implements FocusListener
{
public focusGained(FocusEvent e)
{
}
public focusLost(FocusEvent e)
{
}
}
{
public focusGained(FocusEvent e)
{
}
public focusLost(FocusEvent e)
{
}
}
class TextFocusListener extends FocusAdapter{}
在里面重写
public void focusLost(FocusEvent e){}方法,实现你的想法。
在你的JTextField声明后加入addFocusListener(new TextFocusListener());
jTextField1.addFocusListener(new FocusAdapter(){
public void focusLost(FocusEvent e){
if (jTextField1.getText().length()==0){
JOptionPane.showMessageDialog(null,"ad","",JOptionPane.DEFAULT_OPTION);
}
}
});
jTextField1.addFocusListener(new FocusAdapter(){
public void focusLost(FocusEvent e){
if(e.isTemporary()) return;
if (jTextField1.getText().length()==0){
JOptionPane.showMessageDialog(null,"ad","",JOptionPane.DEFAULT_OPTION);
}
}
});