java – 一次调用两次JComboBox itemStateChanged事件
发布时间:2020-12-14 05:03:00 所属栏目:Java 来源:网络整理
导读:resultCombo = new JComboBox();resultCombo.addItemListener(new ItemListener() { @Override public void itemStateChanged(ItemEvent ie) { sampleText=resultCombo.getSelectedItem().toString(); System.out.println("SampleText : "+sampleText); }});
resultCombo = new JComboBox(); resultCombo.addItemListener(new ItemListener() { @Override public void itemStateChanged(ItemEvent ie) { sampleText=resultCombo.getSelectedItem().toString(); System.out.println("SampleText : "+sampleText); } }); output: SampleText : selectedword SampleText : selectedword 为什么在组合框中选择项目时会调用此事件两次. 解决方法
对于单个更改,JComoboBox ItemListener会被调用两次.一次用于SELECTED事件,一次用于DESELECTED事件.
有关如何编写ItemListener的信息,请参见this tutorial page. 基本上你要做的就是 public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { //Do any operations you need to do when an item is selected. } else if(e.getStateChange() == ItemEvent.DESELECTED){ //Do any operations you need to do when an item is de-selected. } } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |