摆动部件的透明度失效

Question

我一直在使用Color（p，p，p，p）来解决JCombobox的透明度问题。一旦我点击它，所有显示的选项似乎都被光标选中，当它只在其中一个上时。有时其他按钮出现在透明度组件后面，但它们并不在它后面。

透明度确实有效，但我不希望它看起来有问题，我一直在尝试使用paintComponents（）方法和fill rect，它只适用于jcombobox，当它的选项没有显示时，它看起来很完美而不是有问题，但是一旦我显示组合框的选项，这些似乎都被选中并且背后有其他组件的阴影。有没有办法获得包含选项的jcombobox的显示组件，并设置一个不透明的背景或什么来解决这个问题？

这里是Panel的代码，我有3个带MyComboBox的按钮和一个测试类：

//========================== MYCOMBOBOX CLASS ===========================

package views;

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JComboBox;

import models.EnumModels;

public class MyComboBox<E> extends JComboBox<E> {

    public MyComboBox () {
        setOpaque(false);
        setBackground(new Color(18, 10, 44, 100));
    }

    protected void paintComponent(Graphics g)
    {
        g.setColor( getBackground() );
        g.fillRect(0, 0, getWidth(), getHeight());
        super.paintComponent(g);
    }
}
//======================= PANEL WITH MYCOMBOBOX ====================


package views;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;

import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.DefaultComboBoxModel;

import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import controller.Actions;
import controller.EventsController;
import models.EnumModels;

public class CentralPanel extends JPanel{

    MyButton info, add, recent, modelFilter;

    boolean bool;

    JTextField modelField;

    MyComboBox<EnumModels> modelsBox;

    public CentralPanel() {
        setLayout(new BoxLayout(this,BoxLayout.Y_AXIS));
        setSize(600,845);
        setOpaque(false);
        setBackground(new Color(18, 10, 44, 100));
        setBorder(BorderFactory.createLineBorder(Color.decode("#E80909"), 4, true));

        JPanel infoPanel = new JPanel();
        infoPanel.setLayout(new BorderLayout());
        infoPanel.setBorder(BorderFactory.createEmptyBorder(100, 65, 0, 65));
        JPanel addPanel = new JPanel();
        addPanel.setLayout(new BorderLayout());
        addPanel.setBorder(BorderFactory.createEmptyBorder(100, 65, 0, 65));
        JPanel recentPanel = new JPanel();
        recentPanel.setLayout(new BorderLayout());
        recentPanel.setBorder(BorderFactory.createEmptyBorder(100, 65, 0, 65));
        JPanel modelFilterPanel = new JPanel();
        modelFilterPanel.setLayout(new BorderLayout());
        modelFilterPanel.setBorder(BorderFactory.createEmptyBorder(100, 65, 65, 65));


        info = new MyButton();
        info.setFont(new Font("Unispace", Font.BOLD, 24));
        info.setForeground(Color.decode("#E80909"));
        info.setText("Información de Vehículos");
        add = new MyButton();
        add.setFont(new Font("Unispace", Font.BOLD, 24));
        add.setForeground(Color.decode("#E80909"));
        add.setText("Agregar Vehículo");
        recent = new MyButton();
        recent.setFont(new Font("Unispace", Font.BOLD, 24));
        recent.setForeground(Color.decode("#E80909"));
        recent.setText("Vehículos Recientes");
        modelFilter = new MyButton();
        modelFilter.setFont(new Font("Unispace", Font.BOLD, 24));
        modelFilter.setForeground(Color.decode("#E80909"));
        modelFilter.setText("Filtro de Modelo");

        modelsBox = new MyComboBox<>();
        DefaultComboBoxModel model = new DefaultComboBoxModel<>(EnumModels.values());

        modelsBox.setModel(model);
//      modelsBox.setBackground(new Color(18, 10, 44, 100));
        modelsBox.setForeground(Color.decode("#8A7676"));
        modelsBox.setFont(new Font("Unispace", Font.BOLD, 20));
        ((JLabel)modelsBox.getRenderer()).setHorizontalAlignment(SwingConstants.CENTER);
        ((JLabel)modelsBox.getRenderer()).setFocusable(false);
//      ((JLabel)modelsBox.getRenderer()).setOpaque(false);
//      ((JLabel)modelsBox.getRenderer()).setBackground(new Color(18, 10, 44,100));

        info.addActionListener(EventsController.getInstance());
        info.setActionCommand(Actions.MAIN_INFO.name());
        add.addActionListener(EventsController.getInstance());
        add.setActionCommand(Actions.MAIN_ADD.name());
        recent.addActionListener(EventsController.getInstance());
        recent.setActionCommand(Actions.MAIN_RECENT.name());
        modelFilter.addActionListener(EventsController.getInstance());
        modelFilter.setActionCommand(Actions.MAIN_FILTER.name());

        infoPanel.add(info);
        infoPanel.setOpaque(false);
        addPanel.add(add);
        addPanel.setOpaque(false);
        recentPanel.add(recent);
        recentPanel.setOpaque(false);
        modelFilterPanel.add(modelsBox);
        modelFilterPanel.setOpaque(false);

        add(infoPanel);
        add(addPanel);
        add(recentPanel);
        add(modelFilterPanel);

    }

    protected void paintComponent(Graphics g)
    {
        g.setColor( getBackground() );
        g.fillRect(0, 0, getWidth(), getHeight());
        super.paintComponent(g);
    }


///================================ MAIN RUNNER ============================

package test;

import java.awt.Image;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;

import views.CentralPanel;

public class TestViews extends JFrame {

    CentralPanel panel;

    public TestViews() {
        setExtendedState(MAXIMIZED_BOTH);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        panel = new CentralPanel();
        add(panel);
        setVisible(true);
    }

    public static void main(String[] args) {
        new TestViews();
    }
}

//================================ ENUM-COMBOBOX =============================

package models;

public enum EnumModels {


    NOVENTA("1990"),NOVENTA_UNO("1991"),NOVENTA_DOS("1992"),NOVENTA_TRES("1993"),NOVENTA_CUATRO("1994"),NOVENTA_CINCO("1995"),NOVENTA_SEIS("1996"),NOVENTA_SIETE("1997"),NOVENTA_OCHO("1998"),NOVENTA_NUEVE("1999"),
    DOSMIL_UNO("2001"),DOSMIL_DOS("2002"),DOSMIL_TRES("2003"),DOSMIL_CUATRO("2004"),DOSMIL_CINCO("2005"),DOSMIL_SEIS("2006"),DOSMIL_SIETE("2007"),DOSMIL_OCHO("2008"),DOSMIL_NUEVE("2009"),DOSMIL_DIEZ("2010"),DOSMIL_ONCE("2011"),
    DOSMIL_DOCE("2012"),DOSMIL_TRECE("2013"),DOSMIL_CATORCE("2014"),DOSMIL_QUINCE("2015"),DOSMIL_DIEZ_Y_SEIS("2016"),DOSMIL_DIEZ_Y_SIETE("2017"),DOSMIL_DIEZ_Y_OCHO("2018"),DOSMIL_DIEZ_Y_NUEVE("2019"),DOSMIL_VEINTE("2020");

    private String year;

    public String getYear() {
        return this.year;
    }

    private EnumModels(String year) {
        this.year = year;
    }

    public String toString() {
        return year;
    }

}

Answer 1

使用透明背景时，Swing组件无法正确绘制，因为Swing期望组件基于组件的setOpaque（...）属性为不透明或不透明。

如果要使用透明度，则必须手动确保背景涂有以下代码：

JPanel panel = new JPanel()
{
    protected void paintComponent(Graphics g)
    {
        g.setColor( getBackground() );
        g.fillRect(0, 0, getWidth(), getHeight());
        super.paintComponent(g);
    }
};
panel.setOpaque(false); // background of parent will be painted first
panel.setBackground( new Color(255, 0, 0, 20) );
frame.add(panel);

您需要使用透明背景为每个组件自定义绘画。

或者更简单的方法是使用AlphaContainer，它充当组件的包装面板并为您绘制背景。有关更多信息，请参阅Backgrounds With Transparency。