I have a JComboBox which it's items are updating with other parts of program every second. I need a listener when the user tried to type anything there or tried to select an item from JComboBox it updates it's content and show the new items added. I used actionPerformed but it is bringing new items but user can not select then I used itemStateChanged but the program crashed and I had to close netbeans!
我有一个JComboBox，它的项目每秒都会与程序的其他部分一起更新。当用户尝试在那里输入任何内容或尝试从JComboBox中选择一个项目时，我需要一个监听器，它会更新它的内容并显示添加的新项目。我使用actionPerformed但它带来了新的项目，但是用户无法选择然后我使用了itemStateChanged但是程序崩溃了，我不得不关闭netbeans！
Answer: My JcomboBox was on the JPanel. The best way I figure out was to add the listener on JPanel so any element on JPanel even JcomboBox get clicked it will update the comboBox.
答：我的JcomboBox在JPanel上。我弄清楚的最好的方法是在JPanel上添加监听器，这样JPanel上的任何元素甚至JcomboBox都会被点击它会更新comboBox。
My JcomboBox was on the JPanel. The best way I figure out was to add the listener on JPanel so any element on JPanel even JcomboBox get clicked it will update the comboBox.
我的JcomboBox在JPanel上。我弄清楚的最好的方法是在JPanel上添加监听器，这样JPanel上的任何元素甚至JcomboBox都会被点击它会更新comboBox。
2 个解决方案
#1
1
Events effecting the contents of the combo box are generated by the model.
影响组合框内容的事件由模型生成。
Try attaching a ListDataListener to the model itself.
尝试将ListDataListener附加到模型本身。
If you are worried about being notified when/if the model changes, you would need to attach a PropertyChangeListener to the JComboBox and monitor for the model property and update your data listeners accordingly...
如果您担心在/如果模型更改时收到通知，则需要将PropertyChangeListener附加到JComboBox并监视模型属性并相应地更新数据侦听器...
#2
0
ItemListener for when user selects a different item.
用户选择其他项目时的ItemListener。
KeyListener for when the user is typing into the JComboBox.
用户在JComboBox中键入时的KeyListener。
Perhaps your program kept crashing because you weren't using a model for your JComboBox (I'm assuming you kept setting all of the items again)
也许你的程序一直在崩溃，因为你没有为你的JComboBox使用模型（我假设你再次设置了所有的项目）
#1
1
Events effecting the contents of the combo box are generated by the model.
影响组合框内容的事件由模型生成。
Try attaching a ListDataListener to the model itself.
尝试将ListDataListener附加到模型本身。
If you are worried about being notified when/if the model changes, you would need to attach a PropertyChangeListener to the JComboBox and monitor for the model property and update your data listeners accordingly...
如果您担心在/如果模型更改时收到通知，则需要将PropertyChangeListener附加到JComboBox并监视模型属性并相应地更新数据侦听器...
#2
0
ItemListener for when user selects a different item.
用户选择其他项目时的ItemListener。
KeyListener for when the user is typing into the JComboBox.
用户在JComboBox中键入时的KeyListener。
Perhaps your program kept crashing because you weren't using a model for your JComboBox (I'm assuming you kept setting all of the items again)
也许你的程序一直在崩溃，因为你没有为你的JComboBox使用模型（我假设你再次设置了所有的项目）