/// <summary>
/// 获取指定数据上下文类型<typeparamref name="TEntity"/>的实例，并将同数据库连接字符串的上下文实例进行分组归类
/// </summary>
/// <typeparam name="TEntity">实体类型</typeparam>
/// <typeparam name="TKey">实体主键类型</typeparam>
/// <returns><typeparamref name="TEntity"/>所属上下文类的实例</returns>
public IDbContext GetDbContext <TEntity, TKey>() where TEntity : IEntity <TKey> where TKey : IEquatable <TKey>
{
IEntityConfigurationTypeFinder typeFinder = _serviceProvider.GetService <IEntityConfigurationTypeFinder>();
Type entityType = typeof(TEntity);
Type dbContextType = typeFinder.GetDbContextTypeForEntity(entityType);
OSharpDbContextOptions dbContextOptions = GetDbContextResolveOptions(dbContextType);
DbContextResolveOptions resolveOptions = new DbContextResolveOptions(dbContextOptions);
//已存在上下文对象，直接返回
DbContextBase dbContext = _dbContextMamager.Get(dbContextType, resolveOptions.ConnectionString);
if (dbContext != null)
{
return(dbContext);
}
IDbContextResolver contextResolver = _serviceProvider.GetService <IDbContextResolver>();
dbContext = (DbContextBase)contextResolver.Resolve(resolveOptions);
if (!dbContext.ExistsRelationalDatabase())
{
throw new OsharpException($"数据上下文“{dbContext.GetType().FullName}”的数据库不存在，请通过 Migration 功能进行数据迁移创建数据库。");
}
if (resolveOptions.ExistingConnection == null)
{
resolveOptions.ExistingConnection = dbContext.Database.GetDbConnection();
}
_dbContextMamager.Add(dbContextOptions.ConnectionString, dbContext);
return(dbContext);
}