您好,我还是Java的新手,希望学习这个不错的功能…
您好,我有4个组合框,里面和里面的相同

-Select-
Item 1
Item 2
Item 3
Item 4

当我在comboBox1上选择项目1时,
 comboBox2,comboBox3和comboBox4仅具有这些元素

-Select-
Item 2
Item 3
Item 4

然后当我在comboBox2上选择第3项时,comboBox3和comboBox4都有这个剩余元素

-Select-
Item 2
Item 4

有人知道如何在Java上执行此操作吗？我正在Netbeans上使用GUI Builder …

编辑1

这是我的代码

private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {
    jComboBox2.removeItem(jComboBox1.getSelectedItem());
    jComboBox3.removeItem(jComboBox1.getSelectedItem());
    jComboBox4.removeItem(jComboBox1.getSelectedItem());
}

在那之后我添加了相同的代码jComboBox2,jComboBox3和jComboBox4 …
当我选择-选择-时-选择-也消失了…

还有一个问题是,当我已经选择全部并且想再次更改它时…所有项目都消失了,不再有其他选择了..我只想再次备份可用项目…

编辑2

例

jComboBox1
-Select-
Item 1
Item 2 <-- I select Item2, then the other combo box will remove Item 2**
Item 3
Item 4

jComboBox2
-Select-
Item 1
Item 3 <-- then I select Item 3
Item 4

jComboBox3
-Select-
Item 1
Item 4 <-- then Item 4

jComboBox4
-Select-
Item 1 

但是我改变主意了…然后我需要回到jComboBox2以选择Item3
所以我选择
jComboBox2并选择-Select-,因此我可以在jComboBox4上选择item3

但结果是
jComboBox4
空(无项目)

解决方法:

不知道您的两个答案中的哪个将被删除,但这又是相同的答案.请注意,您可以使用循环创建所有JComboBoxes和选项,以防止真正冗长的重复代码.然后,您可以使用getSource()方法来判断事件来自哪个组合框.如果将JComboBoxes创建为数组,则可以非常清晰地循环遍历它们.为了重新添加内容,我只需要跟踪选择了什么以及使用String数组的组合框.然后,您可以检查此数组,并根据需要使用它来添加项目.请注意,它们不会以相同的顺序返回.如果您想要该功能,则可以使用insertItemAt,但这可能会有些混乱(因为自从添加和删除项目以来索引一直在变化),因此我将其省略.

//Declare and initialize the options that the comboboxes will have
String[] options = {"-Select-", "Item 1", "Item 2", "Item 3", "Item 4"};
//Declare and initialize an array that will hold the currently selected options in each combobox by index
//For example the currently selected value of comboBoxes[1] is selected[1]
String[] selected = {"-Select-", "-Select-", "-Select-", "-Select-"};

//Declare and initialize an array of comboBoxes. 
//Four comboboxes will be created all containing the options array
JComboBox[] comboBoxes = new JComboBox[4];
for(int i = 0; i < comboBox.length; i++) {
    comboBoxes[i] = new JComboBox(options);
}

private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {
    //Loop through all of the comboboxes in comboBoxes
    for(int i = 0; i < comboBoxes.length; i++) {
        //Check to see if the current combobox in the array matches the source of your event
        if(evt.getSource() == comboBoxes[i]) {
            //Get the string value of the combobox that fired the event
            String currentSelection = (String)comboBoxes[i].getSelectedItem();
            //Make sure that the value actually changed
            if(!currentSelection.equals(selected[i]) {
                //If the previous value of the combobox was "-Select-" don't add it to all the other comboboxes
                if(!selected[i].equals(options[0])) {
                    //Add back the previous value to all comboboxes other than the one that fired the event
                    for(int j = 0; j < comboBoxes.length; j++) {
                        if(j != i) {
                            comboBoxes[j].addItem(selected[i]);
                        }
                    }
                }
                //If current value of the combobox is "-Select-" don't remove it from all other comboboxes
                if(!currentSelection.equals(options[0]) {
                    //Remove the current value from all comboboxes other than the one that fired the event
                    for(int j = 0; j < comboBoxes.length; j++) {
                        if(j != i) {
                            comboBoxes[j].removeItem(comboBoxes[i].getSelectedItem());
                        }
                    }
                }
            }
            //Set the selected item for the combobox that fired the event to the current value
            selected[i] = currentSelection;
        }
    }
}