/// <summary>
/// 获取指定类型的数据上下文对象
/// </summary>
/// <param name="resolveOptions">上下文解析选项</param>
/// <returns></returns>
public IDbContext Resolve(DbContextResolveOptions resolveOptions)
{
Type dbContextType = resolveOptions.DbContextType;
IDbContextOptionsBuilderCreator builderCreator = _serviceProvider.GetServices <IDbContextOptionsBuilderCreator>()
.FirstOrDefault(m => m.Type == resolveOptions.DatabaseType);
if (builderCreator == null)
{
throw new OsharpException($"无法解析类型为“{resolveOptions.DatabaseType}”的 {typeof(IDbContextOptionsBuilderCreator).FullName} 实例");
}
DbContextOptionsBuilder optionsBuilder = builderCreator.Create(resolveOptions.ConnectionString, resolveOptions.ExistingConnection);
DbContextModelCache modelCache = _serviceProvider.GetService <DbContextModelCache>();
IModel model = modelCache.Get(dbContextType);
if (model != null)
{
optionsBuilder.UseModel(model);
}
DbContextOptions options = optionsBuilder.Options;
//创建上下文实例
if (!(ActivatorUtilities.CreateInstance(_serviceProvider, dbContextType, options) is DbContext context))
{
throw new OsharpException($"实例化数据上下文“{dbContextType.AssemblyQualifiedName}”失败");
}
return(context as IDbContext);
}
/// <summary>
/// 构建<see cref="DbContextOptionsBuilder"/>，附加必要的扩展属性
/// </summary>
public static DbContextOptionsBuilder BuildDbContextOptionsBuilder <TDbContext>(this IServiceProvider provider, DbContextOptionsBuilder builder)
where TDbContext : DbContext
{
Type dbContextType = typeof(TDbContext);
OsharpOptions osharpOptions = provider.GetOSharpOptions();
OsharpDbContextOptions osharpDbContextOptions = osharpOptions?.GetDbContextOptions(dbContextType);
if (osharpDbContextOptions == null)
{
throw new OsharpException($"无法找到数据上下文 {dbContextType.DisplayName()} 的配置信息");
}
ILogger logger = provider.GetLogger(typeof(ServiceExtensions));
//启用延迟加载
if (osharpDbContextOptions.LazyLoadingProxiesEnabled)
{
builder = builder.UseLazyLoadingProxies();
logger.LogDebug($"数据上下文类型 {dbContextType} 应用延迟加载代理");
}
DatabaseType databaseType = osharpDbContextOptions.DatabaseType;
//处理数据库驱动差异处理
IDbContextOptionsBuilderDriveHandler driveHandler = provider.GetServices <IDbContextOptionsBuilderDriveHandler>()
.LastOrDefault(m => m.Type == databaseType);
if (driveHandler == null)
{
throw new OsharpException($"无法解析类型为 {databaseType} 的 {typeof(IDbContextOptionsBuilderDriveHandler).DisplayName()} 实例，是否未在Startup执行AddPack<{databaseType}DefaultDbContextMigrationPack>()");
}
//选择主/从数据库连接串
IConnectionStringProvider connectionStringProvider = provider.GetRequiredService <IConnectionStringProvider>();
string connectionString = connectionStringProvider.GetConnectionString(typeof(TDbContext));
ScopedDictionary scopedDictionary = provider.GetRequiredService <ScopedDictionary>();
string key = $"DbConnection_{connectionString}";
DbConnection existingDbConnection = scopedDictionary.GetValue <DbConnection>(key);
builder = driveHandler.Handle(builder, connectionString, existingDbConnection);
//使用模型缓存
DbContextModelCache modelCache = provider.GetService <DbContextModelCache>();
IModel model = modelCache?.Get(dbContextType);
if (model != null)
{
builder = builder.UseModel(model);
}
return(builder);
}
/// <summary>
/// 将基于Osharp数据上下文基类<see cref="DbContextBase"/>上下文类型添加到服务集合中
/// </summary>
/// <typeparam name="TDbContext">基于Osharp数据上下文基类<see cref="DbContextBase"/>上下文类型</typeparam>
/// <param name="services">依赖注入服务集合</param>
/// <param name="optionsAction">数据库选项创建配置，将在内置配置后运行</param>
/// <returns>依赖注入服务集合</returns>
public static IServiceCollection AddOsharpDbContext <TDbContext>(this IServiceCollection services, Action <IServiceProvider, DbContextOptionsBuilder> optionsAction = null) where TDbContext : DbContextBase
{
services.AddDbContext <TDbContext>((provider, builder) =>
{
Type dbContextType = typeof(TDbContext);
OsharpOptions osharpOptions = provider.GetOSharpOptions();
OsharpDbContextOptions osharpDbContextOptions = osharpOptions?.GetDbContextOptions(dbContextType);
if (osharpDbContextOptions == null)
{
throw new OsharpException($"无法找到数据上下文“{dbContextType.DisplayName()}”的配置信息");
}
//启用延迟加载
if (osharpDbContextOptions.LazyLoadingProxiesEnabled)
{
builder = builder.UseLazyLoadingProxies();
}
DatabaseType databaseType = osharpDbContextOptions.DatabaseType;
//处理数据库驱动差异处理
IDbContextOptionsBuilderDriveHandler driveHandler = provider.GetServices <IDbContextOptionsBuilderDriveHandler>()
.FirstOrDefault(m => m.Type == databaseType);
if (driveHandler == null)
{
throw new OsharpException($"无法解析类型为“{databaseType}”的 {typeof(IDbContextOptionsBuilderDriveHandler).DisplayName()} 实例");
}
ScopedDictionary scopedDictionary = provider.GetService <ScopedDictionary>();
string key = $"DnConnection_{osharpDbContextOptions.ConnectionString}";
DbConnection existingDbConnection = scopedDictionary.GetValue <DbConnection>(key);
builder = driveHandler.Handle(builder, osharpDbContextOptions.ConnectionString, existingDbConnection);
//使用模型缓存
DbContextModelCache modelCache = provider.GetService <DbContextModelCache>();
IModel model = modelCache?.Get(dbContextType);
if (model != null)
{
builder = builder.UseModel(model);
}
//额外的选项
optionsAction?.Invoke(provider, builder);
});
return(services);
}