c# - 错误提示。没有为此 DbContext 配置数据库提供程序

问题描述

我在访问数据库表中的数据时遇到错误，说InvalidOperationException: No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.

我使用了通用存储库模式。我在单独的类库项目中有我的 DbContext 即 BlazorContext 和模型类。

任何帮助都会很感激。

下面是我在 appsettings.json 中的连接字符串

 "ConnectionStrings": {
"myconn": "server=DESKTOP-VM2VP34; database=BlazorDB;Trusted_Connection=True;"
  },<br><br>

下面是我的startup.cs

services.AddDbContext<BlazorContext>(item => item.UseSqlServer(Configuration.GetConnectionString("myconn")));

下面是我的 DbContext 即 BlazorContext

namespace Blazor.Model.Models
{
public class BlazorContext:DbContext
{
    public BlazorContext()
    {
    }

    public BlazorContext(DbContextOptions<BlazorContext> options)
        : base(options)
    {
        Database.EnsureCreated();
    }

    public DbSet<Person> Persons { get; set; }
}
}

下面是我的通用存储库实现，它显示错误

namespace Blazor.Repository.Implementation
{
public class GenericRepository<T> : IGenericRepository<T> where T : class
{
    protected BlazorContext _entities;
    protected readonly DbSet<T> _dbset; // error in this line

    public GenericRepository(BlazorContext context)
    {
        _entities = context;
        _dbset = context.Set<T>();
    }

    public IEnumerable<T> GetAll()
    {
        return _dbset.AsEnumerable();
    }
}
}

下面是我的 GenericUnitOfWork

namespace Blazor.Repository.Implementation
{
public sealed class GenericUnitOfWork : IGenericUnitOfWork, IDisposable
{
    private BlazorContext entities = null;
    public GenericUnitOfWork()
    {
        entities = new BlazorContext();
    }

    public Dictionary<Type, object> repositories = new Dictionary<Type, object>();

    public IGenericRepository<T> Repository<T>() where T : class
    {
        if (repositories.Keys.Contains(typeof(T)) == true)
        {
            return repositories[typeof(T)] as IGenericRepository<T>;
        }
        var t = typeof(T);

        IGenericRepository<T> repo = new GenericRepository<T>(entities);//error in this line
        repositories.Add(typeof(T), repo);
        return repo;
    }
}
}

标签： c#asp.net-coreentity-framework-core

c# - 错误提示。没有为此 DbContext 配置数据库提供程序

问题描述

解决方案

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