從自定義類.Net核心訪問DbContext

Question

我需要從一個處理類中訪問我的DbContext，該類在Startup.cs類的configure方法中實例化。如何實例化我的處理程序類以便使用在Startup.ConfigureServices方法中使用依賴注入容器註冊的數據庫上下文。

這是我的代碼：

Startup.cs：

public void ConfigureServices(IServiceCollection services) 
{ 

    var connection = @"Server=MyDb;Initial Catalog=MYDB;Persist Security Info=True; Integrated Security=SSPI;"; 
    services.AddDbContext<iProfiler_ControlsContext>(options => options.UseSqlServer(connection)); 

    //......... 
} 

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) 
{ 
    //............. 

    options.SecurityTokenValidators.Add(new MyTokenHandler(MY INSTANCE OF DBCONTEXT HERE)); 
    app.UseJwtBearerAuthentication(options); 

    //.............. 

} 

處理類：

internal class MyTokenHandler : ISecurityTokenValidator 
{ 
    private JwtSecurityTokenHandler _tokenHandler; 
    private iProfiler_ControlsContext _context; 

    public MyTokenHandler(iProfiler_ControlsContext context) 
    { 
     _tokenHandler = new JwtSecurityTokenHandler(); 
     _context = context; 
    } 

    public ClaimsPrincipal ValidateToken(string securityToken, TokenValidationParameters validationParameters, out SecurityToken validatedToken) 
    { 

    var principal = _tokenHandler.ValidateToken(securityToken, validationParameters, out validatedToken); 

    var tblVerificationPortalTimeStamps = _context.TblVerificationPortalTimeStamps.ToList(); 

    //......   

    } 
} 

Answer 1

首先更新ConfigureServices從服務集合返回一個服務提供商。

public IServiceProvider ConfigureServices(IServiceCollection services) { 

    var connection = @"Server=MyDb;Initial Catalog=MYDB;Persist Security Info=True; Integrated Security=SSPI;"; 
    services.AddDbContext<iProfiler_ControlsContext>(options => options.UseSqlServer(connection)); 

    //......... 

    var provider = services.BuildServiceProvider(); 
    return provider; 
} 

下次更新Configure方法注入IServiceProvider

public void Configure(IApplicationBuilder app, IHostingEnvironment env, 
         ILoggerFactory loggerFactory, IServiceProvider provider) { 
    //............. 

    var dbContext = provider.GetService<iProfiler_ControlsContext>(); 
    options.SecurityTokenValidators.Add(new MyTokenHandler(dbContext)); 
    app.UseJwtBearerAuthentication(options); 

    //.............. 

}