jcombobox

问题 I have a problem with making JComboBox transparent. I tried setting opaque to false and alpha of background 0 but it doesnt work. I guess that i need to change some class that does rendering or something similar.And here is the code.. import java.awt.EventQueue; import java.awt.Graphics; import java.awt.Rectangle; import javax.swing.JFrame; import javax.swing.JComboBox; import javax.swing.JTextField; import javax.swing.plaf.basic.BasicComboBoxUI; import java.awt.Color; public class App {

问题 I've got an ArrayList of objects, and all the objects have names. How can I populate a JComboBox with those names? I've looked online and found nothing so far. There are some resources, but they tend to go with a hardcoded version, which is useless. Since I don't have any code yet showing what I'm doing, I can't attach any. 回答1: JComboBox works with Array or Vector . You should use .toArray() method in the ArrayList to create an array. String[] names = namesList.toArray(new String[0]); then

问题 I am attempting to write a pretty short class that "ties" a JPanel to a JComboBox. I think I have the logic down, but nothing happens when I select something new using the JComboBox... Here is (more or less) my code: private DisplayPanel currentDisplay; //a displaypanel is simply an extended JPanel with an id field, and an overriden .equals() method private JComboBox selector; private List<DisplayPanel> displays; public SelectionPanel(DisplayPanel panel){ displays = new ArrayList<DisplayPanel

问题 I am attempting to write a pretty short class that "ties" a JPanel to a JComboBox. I think I have the logic down, but nothing happens when I select something new using the JComboBox... Here is (more or less) my code: private DisplayPanel currentDisplay; //a displaypanel is simply an extended JPanel with an id field, and an overriden .equals() method private JComboBox selector; private List<DisplayPanel> displays; public SelectionPanel(DisplayPanel panel){ displays = new ArrayList<DisplayPanel

问题 At beginning I will say that I don't have in mind auto-complete combobox, but rather having a "setFilter(Set)" method in my combobox, so it displays what is in the set. I was unable to achieve that effect, trying different approaches and I think it's the view responsibility to filter what it displays, so I should not extend ComboBoxModel. This is what I have so far (main includes the case which doesn't work): import java.awt.*; import java.util.Set; import javax.swing.*; public class

问题 I have a ComboBox in which I have 8 Items out of which I want to display all but on a certain condition, the user should only be able to select the first two of them, so I have programmed that if the condition is true and the user chooses any other option then it shows up a Message Box showing "You cannot choose this" and then selecting the default automatically. So far so good. But now the thing is that the user cannot make out by seeing the options of JComboBox that which ones can he select

问题 I'd like to change OOTB behaviour of combobox, to freeze it after right mouse button click (detecting which button was clicked is easy, so that's not the point) and open JPopupMenu istead of choosing that entry. So - how to disable choosing entry on given condition and use custom behaviour then? I tried to start by adding mouse listeners to all combobox components, but without success - nothing changed import java.awt.BorderLayout; import java.awt.Component; import java.awt.event.MouseAdapter

问题 I have a written an AbstractTableModel for my JTable in my application. I see from tutorials that I can make the column to have a combobox by getting the column model and then the specific column for example: TableColumn sportColumn = table.getColumnModel().getColumn(2); ... JComboBox comboBox = new JComboBox(); comboBox.addItem("Snowboarding"); comboBox.addItem("Rowing"); comboBox.addItem("Chasing toddlers"); comboBox.addItem("Speed reading"); comboBox.addItem("Teaching high school");

问题 I'm doing a search on the database using an editable JComboBox, but when it comes to writing, only accepts write me a letter and any amount of numbers, how I can do that allows me to write letters and numbers? The following code accepts only numbers, backspace key, enter key, but not letters. comboBusqueda.getEditor().getEditorComponent().addKeyListener(new KeyAdapter() { public void keyPressed(KeyEvent evt) { String cadenaEscrita = comboBusqueda.getEditor().getItem().toString(); if (evt

问题 class RuleComboBox extends JComboBox { public RuleComboBox() { super(); this.setModel(new javax.swing.DefaultComboBoxModel(new String[]{"abc", "defg"})); ((JLabel) this.getRenderer()).setHorizontalAlignment(SwingConstants.CENTER); } } The getRenderer() line aligns the text to centre. When I use ruleComboBox1.setEnabled(false) and ruleComboBox1.setEditable(true) , the text aligns back to the left which I don't want. How can I stop this? I should explain that I'm using setEditable(true) to keep