C#控制台连接Mysql数据库，有配置数据库连接字符串的配置文件

实现功能

1. 读取..txt 中的配置文件，来初始化连接字符串
2. 让连接字符串的配置文件不存在会主动创建默认的连接字符串

注意点：

1. 需要引用Newtonsoft
2. 使用mysql

代码如下

using System;
using MySql.Data.MySqlClient;
using Newtonsoft.Json;namespace 连接数据库
{class Program{static void Main(string[] args){string filePath = AppDomain.CurrentDomain.BaseDirectory + "ConnectionStrConfig.txt";//设置文件路径if (!System.IO.File.Exists(filePath))//判断文件是否存在{Console.WriteLine("文件不存在！已创建新的文件，请重启程序");System.IO.File.CreateText(filePath);//创建文件System.IO.File.WriteAllText(filePath, CreateDefaultConnectionString());//写入文件内容，默认的数据库配置文件return;//程序退出}string configFile = System.IO.File.ReadAllText(filePath);//读取文件内容if (configFile.Length == 0)//文件内容是空的{Console.WriteLine("没有读取到内容");System.IO.File.WriteAllText(filePath, CreateDefaultConnectionString());//写入文件内容，默认的数据库配置文件return;}Console.WriteLine(configFile);ConnectionStrConfig connectionStrConfig;try{connectionStrConfig = JsonConvert.DeserializeObject<ConnectionStrConfig>(configFile);//将读取到的内容转成配置文件的对象}catch (Exception e){Console.WriteLine("Josn 序列化失败，检查配置文件");//转换失败Console.ReadKey();return;}if (connectionStrConfig.Database == null){Console.WriteLine("Josn 序列化失败，检查配置文件");//转换失败return;}// 与数据库连接的信息MySqlConnectionStringBuilder builder = new MySqlConnectionStringBuilder();//用户名builder.UserID = connectionStrConfig.UserID;//密码builder.Password = connectionStrConfig.Password;//服务器地址builder.Server = connectionStrConfig.Server;//连接时的数据库builder.Database = connectionStrConfig.Database;//设置端口号builder.Port = connectionStrConfig.Port;//定义与数据连接的链接MySqlConnection connection = new MySqlConnection(builder.ConnectionString);//打开这个链接connection.Open();//connection.OpenAsync();Console.WriteLine("这是一个控制台程序");Console.WriteLine("这是一个控制台程序，数据库连接完成");Console.ReadKey();connection.Close();//数据库连接关闭//connection.CloseAsync();Console.WriteLine("数据库连接断开");Console.ReadKey();}/// <summary>/// 创建默认的连接字符串/// </summary>/// <returns>默认的配置文件的string</returns>static string CreateDefaultConnectionString(){string defaultString = "";//默认连接字符串的配置文件ConnectionStrConfig connectionStrConfig = new ConnectionStrConfig("root", "root", "localhost", "testdatabase", 3308);//通过”构造函数“ 创建默认的连接字符串的配置文件defaultString = JsonConvert.SerializeObject(connectionStrConfig);//Json序列化为stringreturn defaultString;}}[Serializable]class ConnectionStrConfig{private string userid;private string password;private string server;private string database;private uint port;/// <summary>/// 用户名/// </summary>public string UserID{get{return userid;}private set{userid = value;}}/// <summary>/// 密码/// </summary>public string Password{get{return password;}private set{password = value;}}/// <summary>/// 服务地址/// </summary>public string Server{get{return server;}private set{server = value;}}/// <summary>/// 数据库名称/// </summary>public string Database{get{return database;}private set{database = value;}}/// <summary>/// 端口号/// </summary>public uint Port{get{return port;}private set{port = value;}}/// <summary>/// 数据库连接字符串的配置文件/// </summary>/// <param name="userid">用户名</param>/// <param name="password">密码</param>/// <param name="server">服务</param>/// <param name="database">数据库名称</param>/// <param name="port">端口号</param>public ConnectionStrConfig(string userid, string password,string server,string database,uint port){this.userid = userid;this.password = password;this.server = server;this.database = database;this.port = port;}//public ConnectionStrConfig()//{当反序列化对象的时候，被反序列化的对象如果有get或者set修饰的属性，那么就不可以显式的写无参的构造函数。//}}}