小编mv7*_*700的帖子

我有一个程序在循环中构建一个字符串,我的程序太慢了.现在需要大约600毫秒才能运行Oblig1Test.oppgave7.有什么办法可以加快速度？

Oblig1.toString:

public static String toString(int[] a, char v, char h, String mellomrom)
{
    String s ="";

    s += v;

    if(a.length != 0)
    {
        for(int i = 0; i < a.length-1; i++)
        {
                s += a[i] + mellomrom; 
        }

        s += a[a.length-1];
    }

    s += h;

    return s;
}

Oblig1Test:

public static int oppgave7()
{
   int[] b = new int[20000];
   long tid = System.currentTimeMillis();
   Oblig1.toString(b,' ',' '," ");
   tid = System.currentTimeMillis() - tid;

  if (tid > 40) …

这段代码有点问题.该actionPerformed方法不起作用.按钮knappStartSalg和knappStartKunde,当我按动按钮没有反应.

应该导入的所有内容都是导入的.

非常感谢任何帮助.

开始上课.

public class Startmeny extends JFrame implements ActionListener
{

    public JButton knappStartSalg, knappStartKunde, knappStartInfo, knappStartStatistikk;

    public JPanel startmeny()
    {
    JPanel startpanel = new JPanel();
    startpanel.setLayout(new GridLayout(2, 0, 25, 25) );
    startpanel.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
    startpanel.setBackground(Color.white);

    JButton knappStartSalg = new JButton();
    knappStartSalg.setText("Salg");
    knappStartSalg.setVerticalTextPosition(JButton.BOTTOM);
    knappStartSalg.setHorizontalTextPosition(JButton.CENTER);
    knappStartSalg.setIcon(new javax.swing.ImageIcon(getClass().getResource("salg.png")));
    knappStartSalg.setIconTextGap(6);
    knappStartSalg.setForeground(Color.black);
    knappStartSalg.setBackground(Color.white);
    knappStartSalg.setBorderPainted(false);
    knappStartSalg.addActionListener(this);

    startpanel.add(knappStartSalg);

    JButton knappStartKunde = new JButton();
    knappStartKunde.setText("Kontroll");
    knappStartKunde.setVerticalTextPosition(JButton.BOTTOM);
    knappStartKunde.setHorizontalTextPosition(JButton.CENTER);
    knappStartKunde.setIcon(new javax.swing.ImageIcon(getClass().getResource("heiskontroll.png")));
    knappStartKunde.setIconTextGap(6);
    knappStartKunde.setForeground(Color.black);
    knappStartKunde.setBackground(Color.white);
    knappStartKunde.setBorderPainted(false);
    knappStartKunde.addActionListener(this);

    startpanel.add(knappStartKunde);

    JButton knappStartInfo = new JButton();
    knappStartInfo.setText("Informasjonsvindu");
    knappStartInfo.setVerticalTextPosition(JButton.BOTTOM); …