不使用OnConfiguring（DbContextOptionsBuilder optionsBuilder）无法构造DbContext

Question

我正在开发具有DLL（EF Core 2.1）中声明的DbContext的.NET CORE MVC 2.1 Web应用程序。

我想使用IServiceCollection.AddContext<GladContext>来配置上下文，但是如果我没有 ALSO 对其进行配置DbContext.OnConfiguring(DbContextOptionsBuilder optionsBuilder)，则会被告知尚未配置任何数据库提供程序尽管有一个构造函数使用DbContextOptions<GladContext>

    public GladContext(DbContextOptions<GladContext> options, IGladConnectionStringProvider connectionStringProvider) : base(options)
    {
        _connectionStringProvider = connectionStringProvider;
    }
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        GladOptionsBuilderHelper.ConfigureDefaultOptionsBuilder(optionsBuilder, _connectionStringProvider.ConnectionString);
        base.OnConfiguring(optionsBuilder);
    }

IGladConnectionStringProvider是我当前的解决方法，如果不是，那是可以接受的，因为我现在需要同时配置DbContextOptionsBuilder和DbContextOptionsBuilder<GladContext>

public static class GladOptionsBuilderHelper
{

    public const string GladMigrationsHistory = "__GladMigrationsHistory";
    public static DbContextOptionsBuilder<GladContext> CreateDefaultTypedOptionsBuilder(string connectionString) 
    {

        var optionsBuilder = new DbContextOptionsBuilder<GladContext>();

        optionsBuilder
            .UseSqlServer(connectionString, options =>
            {
                options.EnableRetryOnFailure();
                options.MigrationsHistoryTable(GladMigrationsHistory, EntityBase.SchemaName);
            })
            .ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));

        return optionsBuilder;
    }


    public static void ConfigureDefaultOptionsBuilder(DbContextOptionsBuilder optionsBuilder, string connectionString)
    {
        optionsBuilder
            .UseSqlServer(connectionString, options =>
            {
                options.EnableRetryOnFailure();
                options.MigrationsHistoryTable(GladMigrationsHistory, EntityBase.SchemaName);
            })
            .ConfigureWarnings(warnings => warnings.Throw(RelationalEventId.QueryClientEvaluationWarning));

    }
}

DbContextOptionsBuilder<GladContext>中使用了IDesignTimeDbContextFactory<GladContext>

您能告诉我如何使用AddContext来配置GladContext或如何从DbContextOptionsBuilder来构建DbContextOptionsBuilder<GladContext>或相反吗？

Answer 1

其中的配置部分是IServiceCollection.AddDbContext（）的覆盖。

因此，当您调用AddDbContext时，只需将您的选项添加到括号中即可，如下所示：

var connectionString = "CONNECTION-STRING-HERE";

services.AddDbContext<MyContext>(o => o
                .UseSqlServer(connectionString)
                .UseQueryTrackingBehavior(true)
                .EnableSensitiveDataLogging(true));



public class MyContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }

    public MyContext(DbContextOptions<MyContext> options) : base(options)
    { 

    }
}