Java-如果在combox1中选择了一个值，则应在所有其他组合框中将其禁用

Question

您好，我仍然是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

当我选择Item 1时comboBox1，comboBox2,comboBox3 and comboBox4只有这些元素

-Select-
Item 2
Item 3
Item 4

然后当我选择Item 3on时comboBox2，comboBox3 and comboBox4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());
}

我添加相同的代码jComboBox2, jComboBox3 and jComboBox4之后......当我去选择-Select-的-Select-是没了......和

还有一个问题是，当我已经全部选择并打算再次更改时…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

但我改变了我的脑海里......然后我需要回去 jComboBox2选择Item3 ，所以我选择
jComboBox2和选择-Select-，这样我就可以选择item3上jComboBox4

但结果是jComboBox4为空（无项目）

Answer 1

不知道您的两个答案中的哪个将被删除，但是这里又是相同的答案。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，我只需要跟踪已选择的内容以及使用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;
        }
    }
}