在JFrame中显示.png图像？

本文介绍了在JFrame中显示.png图像？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有点卡住了。为什么不这样做？我只是得到一个错误说：

I am a little stuck. Why wont this work? I just get a error saying:

java.lang.NoSuchMethodError：main

java.lang.NoSuchMethodError: main

线程main中的异常

import java.awt.*; import javax.swing.*; @SuppressWarnings("serial") public class ShowPNG extends JFrame { public void main(String arg) { if (arg == null ) { arg = "C:/Eclipse/workspace/ShowPNG/bin/a.png"; } JPanel panel = new JPanel(); panel.setSize(500,640); panel.setBackground(Color.CYAN); ImageIcon icon = new ImageIcon(arg); JLabel label = new JLabel(); label.setIcon(icon); panel.add(label); this.getContentPane().add(panel); this.setVisible(true); } }

推荐答案

main需要是静态的，并且必须有一个String []的参数，而不是String。

main needs to be static, and must have an argument of String[], not String.

要修复这个在构造函数中的所有内容，例如

To fix this stick everything in a constructor, such as

import java.awt.*; import javax.swing.*; @SuppressWarnings("serial") public class ShowPNG extends JFrame { private ShowPNG(String arg){ if (arg == null ) { arg = "C:/Eclipse/workspace/ShowPNG/bin/a.png"; } JPanel panel = new JPanel(); panel.setSize(500,640); panel.setBackground(Color.CYAN); ImageIcon icon = new ImageIcon(arg); JLabel label = new JLabel(); label.setIcon(icon); panel.add(label); this.getContentPane().add(panel); } public static void main(String[] args) { new ShowPNG(args.length == 0 ? null : args[0]).setVisible(true); } }