如何获得用可编辑的JComboBox编写的值？ [英] How to get value that has been written in editable JComboBox?

问题描述

我一直在搜索，似乎每个人都只使用 JComboBox＃getSelectedItem 。但我的组合框可编辑，用户可以输入任何内容。 getSelectedItem 方法返回组合框中的一个实际项目，而不是字段中输入的字符串。

I keep searching and it seems like everybody is using only the JComboBox#getSelectedItem. But my combo box is editable and the user can enter anything. The getSelectedItem method returns one of the actual items in the combo box, not a string entered in the field.

如果我的包含Bar和项目和用户输入Foo，我想得到Foo！

If my box contains "Bar" and "Item" and user enters "Foo", I want to get "Foo"!

有人指出 getSelectedItem 也会返回输入的字符串。但是没有指出，这仅在用户停止编辑字段后才有效。我附加了这些事件监听器：

It was pointed out that getSelectedItem does also return the string entered. It was not pointed out though, that this only works after the user stops editing the field. I attached these event listeners:

Component[] comps = input.getComponents();
//Third is the text field component
comps[2].addKeyListener(new KeyListener() {
  public void keyTyped(KeyEvent e) {
    doSomething();
  }
});
//Also fire event after user leaves the field
input.addActionListener (new ActionListener () {
    @Override
    public void actionPerformed(ActionEvent e) {
      doSomething();
    }
});

这就是结果：

KeyEvent:
 JComboBox.getEditor().getItem() = 6  
 JComboBox.getSelectedItem()     = null
KeyEvent:
 JComboBox.getEditor().getItem() = 66
 JComboBox.getSelectedItem()     = null
KeyEvent:
 JComboBox.getEditor().getItem() = 666
 JComboBox.getSelectedItem()     = null
ActionEvent:
 JComboBox.getEditor().getItem() = 6666
 JComboBox.getSelectedItem()     = 6666

如您所见，动作事件监听器可以捕获值，但关键事件不能。

As you can see, the action event listener could capture the value, but the key event could not.

推荐答案

这样： combobox.getEditor（）。getItem（）。不错的画作。

这篇关于如何获得用可编辑的JComboBox编写的值？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！