diaolizhi

class OnlyYou
{
    //构造函数
    private OnlyYou()
    {

    }

    //注意类型是 OnlyYou，并且是静态的
    private static OnlyYou obj = null;

diaolizhi

public partial class Form2 : Form
{
    //唯一实例
    private static Form2 obj = null;
    
    private Form2()
    {
        //初始化控件（自动生成）
        InitializeComponent();
    }

diaolizhi

private void Form2_FormClosing(object sender, FormClosingEventArgs e)
{
    e.Cancel = (MessageBox.Show("Sure?",
                            "Exit",
                            MessageBoxButtons.YesNo,
                            MessageBoxIcon.Question) == DialogResult.Yes);

    DialogResult result = MessageBox.Show("提示", "确定退出吗？", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
    if (result == DialogResult.Yes)
    {

diaolizhi

public static void shuffle(Object[] a) {
    //判断数组 a 是否可以转为整型数组 
    validateNotNull(a);
    int n = a.length;
    for (int i = 0; i < n; i++) {
        int r = i + uniform(n-i);     // between i and n-1
        Object temp = a[i];
        a[i] = a[r];
        a[r] = temp;
    }

diaolizhi

public Form1()
{
    //TimerCallback 是委托类型，可以关联一个形参为 Object 的函数
    TimerCallback timerCallback = new TimerCallback(timeUpdate);

    //Timer 每隔 1000ms 调用委托
    System.Threading.Timer timer = new System.Threading.Timer(timerCallback, "", 0, 1000);
}

public void timeUpdate(Object obj)

diaolizhi

//读
btn1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(MainActivity.this, WizardOne.class);
        intent.putExtra("setting", setting);
        startActivityForResult(intent, 1);
    }
});

diaolizhi

btnFinish.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intentToFinish = new Intent(WizardThree.this, FinishActivity.class);
        //重点是下面这一句
        intentToFinish.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        intentToFinish.putExtra("setting", setting);
        startActivity(intentToFinish);
        WizardThree.this.finish();
    }

diaolizhi

package chapter3;

/**
 * @program: studythread2
 * @description: synchronized Demo
 * @author: diaolizhi
 * @create: 2018-11-13 10:29
 **/
public class SynchronizedDemo {

diaolizhi

package chapter3;

/**
 * @program: studythread2
 * @description: 懒汉式单例模式
 * @author: diaolizhi
 * @create: 2018-11-13 12:39
 **/
public class LazySingleton {

diaolizhi

package com.diaolizhi.mybatisdemo.utils;

import com.diaolizhi.mybatisdemo.domain.User;
import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;


import java.util.Date;