net core依赖注入设置数据库连接

一、在appsetting.json中设置数据库连接字符串 

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{ "ConnectionStrings": {     "DianXinMySql": "server=localhost;port=3306;user=root;password=password;database=db_name" }, "Logging": {     "LogLevel": {     "Default": "Information",     "Microsoft.AspNetCore": "Warning"     } }, "AllowedHosts": "*" }

　　 

二、在Program.cs中添加如下代码

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builder.Services.AddDbContext<TelecomDbContext>(options =>     options.UseMySQL(builder.Configuration.GetConnectionString("DianXinMySql")));     其他写法： IConfiguration configuration = new ConfigurationBuilder()     .AddJsonFile("appsettings.json", true, true)     .Build();   //IConfiguration configuration = new ConfigurationBuilder().SetBasePath(Environment.CurrentDirectory).AddJsonFile("appsettings.json").Build();    builder.Services.AddDbContext<TelecomDbContext>(options => {     options.UseMySQL(configuration.GetConnectionString("DianXinMySql")); });

　

三、在Controller依赖注入后调用

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public class HomeController : Controller {     private readonly ILogger<HomeController> _logger;     private readonly TelecomDbContext _bd;       public HomeController(ILogger<HomeController> logger, TelecomDbContext bd)     {         _logger = logger;         _bd = bd;     }       public IActionResult Index()     {           var list = _bd.CommonDistributionPtCities.ToList();         return View();     } }