java

2024-07-12 16:01| 来源: 网络整理| 查看: 265

我创建了一个 JFrame，它包含一个 JPanel。我创建了许多 JLabel。我可以将 JLabels 添加到 JPanel，并正确显示它们。但我想实现它们，以便它们按顺序显示；每个 JLabel 显示之间的时间延迟。

搜索StackOverfLow后，我尝试了一些代码，但没有效果!。那么如何使用定时器，通过设置时间延迟，使组件(标签)依次显示出来。

我不想修复我的代码，特别是在答案中。只是展示如何以延迟的方式显示任何类型的组件，每个组件一段时间后显示的组件。就这些。我提供了我的代码来展示我为解决问题所做的努力。

首先，这是要使用的 JLabel 的子类:(没有问题)

import java.awt.Color; import java.awt.Dimension; import java.awt.Font; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.BorderFactory; import javax.swing.JLabel; public class DLabel extends JLabel { Dimension size = new Dimension(70, 75); Font font = new Font(Font.SANS_SERIF, 12, 35); public DLabel(String t) { this.setPreferredSize(size); this.setBorder(BorderFactory.createBevelBorder(1, Color.white, Color.black)); this.setVerticalAlignment(JLabel.CENTER); this.setHorizontalAlignment(JLabel.CENTER); this.setText(t); this.setFont(font); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g; Color color1 = new Color(226, 218, 145); Color color2 = color1.brighter(); int w = getWidth(); int h = getHeight(); GradientPaint gp = new GradientPaint( 0, 0, color1, 0, h, color2); g2d.setPaint(gp); g2d.fillRect(0, 0, w, h); super.paintComponent(g); } }

使用DLabel类的另一个类:

import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.Timer; import javax.swing.UIManager; public class DelayedLabels extends JPanel { static JFrame frame; Timer timer; //timer to be used for dealy DLabel card_1; //Defining the DLabels DLabel card_2; DLabel card_3; JLabel[] labelsArray; public DelayedLabels() { this.setLayout(null); card_1 = new DLabel("1"); card_2 = new DLabel("2"); card_3 = new DLabel("3"); labelsArray = new DLabel[3]; //create the array createLabelsArray(); //add the Labels Objects to labelsArray setLabelsLocations(labelsArray); // set the locations of the Labels to be displayed on the JPanel addLabelsToPanel(labelsArray); //The adding of the Labels to the JPanel } private void createLabelsArray() { labelsArray[0] = card_1; labelsArray[1] = card_2; labelsArray[2] = card_3; } private void setLabelsLocations(JLabel[] labels) { int length = labels.length; int gap = 10; int counter = 10; for (int i = 0; i < length; i++) { labels[i].setBounds(170, counter, 60, 70); counter = counter + labels[i].getBounds().height + gap; } } private void addLabelsToPanel(JLabel[] labels) { for (int i = 0; i < labels.length; i++) { frame.revalidate(); frame.repaint(); this.add(labels[i]); timer = new Timer(1000, timerAction); //timer to use with 1000 milliseconds timer.start(); } } private ActionListener timerAction = new ActionListener() //action to be invoked after each label added { @Override public void actionPerformed(ActionEvent ae) { frame.revalidate(); frame.repaint(); } }; private static void createAndShowGUI() { frame = new JFrame(); frame.setSize(600, 700); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); DelayedLabels demo = new DelayedLabels(); demo.setOpaque(true); frame.add(demo); frame.setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { UIManager.put("swing.boldMetal", Boolean.FALSE); createAndShowGUI(); } }); } }

最佳答案

import java.awt.*; import java.awt.event.*; import javax.swing.*; public class DelayedLabels extends JPanel { static JFrame frame; Timer timer; //timer to be used for dealy JLabel card_1; //Defining the JLabels JLabel card_2; JLabel card_3; JLabel[] labelsArray; ActionListener listener; public DelayedLabels() { listener = new ActionListener() { int i = 0; @Override public void actionPerformed(ActionEvent e) { Component c = DelayedLabels.this.getTopLevelAncestor(); DelayedLabels.this.add(labelsArray[i++]); c.validate(); c.repaint(); if (i==labelsArray.length) { timer.stop(); } } }; this.setLayout(new GridLayout(0, 1, 20, 20)); card_1 = new JLabel("Label 1"); card_2 = new JLabel("Label 2"); card_3 = new JLabel("Label 3"); labelsArray = new JLabel[3]; //create the array createLabelsArray(); //add the Labels Objects to labelsArray timer = new Timer(1000,listener); timer.start(); } private void createLabelsArray() { labelsArray[0] = card_1; labelsArray[1] = card_2; labelsArray[2] = card_3; } private static void createAndShowGUI() { frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); DelayedLabels demo = new DelayedLabels(); demo.setOpaque(true); frame.add(demo, BorderLayout.PAGE_START); frame.pack(); frame.setSize(200, 150); frame.setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { UIManager.put("swing.boldMetal", Boolean.FALSE); createAndShowGUI(); } }); } }

关于java - 如何在向 JFrame 添加组件之间添加时间延迟？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14302180/

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