关于combobox

Question

你可以设一个String变量来存放上一次选中的Item：
String preItem;
preItem = jComboBox1.getSelectedItem().toString();

Answer 1

问题是我在哪个event里加这句话啊???

Answer 2

private Object lastSelected;
jComboBox1.addActionListener(new ActionListener() {
   public void actionPerformed(ActionEvent e ) {
      Object obj = jComboBox1.getSelectedItem();
      if( obj != lastSelected ) {
          lastSelected  = obj;
          ....
      }
   }
});

Answer 3

给你个例子：
String selectedItem = "";jComboBox1.addActionListener(new java.awt.event.ActionListener() {
  public void actionPerformed(ActionEvent e) {
    jComboBox1_actionPerformed(e);
  }
});void jComboBox1_actionPerformed(ActionEvent e) {
  if(!(selectedItem.equals(jComboBox1.getSelectedItem().toString()))){
    selectedItem = jComboBox1.getSelectedItem().toString();
    //···
  }
}