系统启动时执行任务：IStartupTask,启动时执行的任务主要是数据库的初始化和加载。
IStartupTask调用IEfDataProvider进行数据库的初始化。
IEfDataProvider,SqlCeDataProvider：获取数据连接工厂，不同类型数据库，连接工厂不同。
接口IStartupTask的实体类EfStartUpTask的实现如下：
public class EfStartUpTask : IStartupTask
{
public void Execute()
{
var settings = EngineContext.Current.Resolve<DataSettings>();
if (settings != null && settings.IsValid())
{
var provider = EngineContext.Current.Resolve<IEfDataProvider>();
if (provider == null)
throw new NopException("No EfDataProvider found");
provider.SetDatabaseInitializer();
}
}
public int Order
{
//ensure that this task is run first
get { return -1000; }
}
}
SqlCeInitializer，CreateCeDatabaseIfNotExists初始化数据库。
IDbContext，NopObjectContext系统数据库操作上下文。加载所有数据库映射类：EntityTypeConfiguration<TEntityType>。代码如下：
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//dynamically load all configuration
//System.Type configType = typeof(LanguageMap); //any of your configuration classes here
//var typesToRegister = Assembly.GetAssembly(configType).GetTypes()
var typesToRegister = Assembly.GetExecutingAssembly().GetTypes()
.Where(type => !String.IsNullOrEmpty(type.Namespace))
.Where(type => type.BaseType != null && type.BaseType.IsGenericType && type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
foreach (var type in typesToRegister)
{
dynamic configurationInstance = Activator.CreateInstance(type);
modelBuilder.Configurations.Add(configurationInstance);
}
//...or do it manually below. For example,
//modelBuilder.Configurations.Add(new LanguageMap());
base.OnModelCreating(modelBuilder);
}
此方法是继承自DbContext。并在系统启动时调用，建立数据表与实体的对应关系。
在类型依赖注册类Nop.Web.Framework.DependencyRegistrar中实现数据库工厂的创建、数据库的加载。如下代码：
//data layer
var dataSettingsManager = new DataSettingsManager();
var dataProviderSettings = dataSettingsManager.LoadSettings();
builder.Register(c => dataSettingsManager.LoadSettings()).As<DataSettings>();
builder.Register(x => new EfDataProviderManager(x.Resolve<DataSettings>())).As<BaseDataProviderManager>().InstancePerDependency();
builder.Register(x => (IEfDataProvider)x.Resolve<BaseDataProviderManager>().LoadDataProvider()).As<IDataProvider>().InstancePerDependency();
builder.Register(x => (IEfDataProvider)x.Resolve<BaseDataProviderManager>().LoadDataProvider()).As<IEfDataProvider>().InstancePerDependency();
if (dataProviderSettings != null && dataProviderSettings.IsValid())
{
var efDataProviderManager = new EfDataProviderManager(dataSettingsManager.LoadSettings());
var dataProvider = (IEfDataProvider)efDataProviderManager.LoadDataProvider();
dataProvider.InitConnectionFactory();
builder.Register<IDbContext>(c => new NopObjectContext(dataProviderSettings.DataConnectionString)).InstancePerHttpRequest();
}
else
{
builder.Register<IDbContext>(c => new NopObjectContext(dataSettingsManager.LoadSettings().DataConnectionString)).InstancePerHttpRequest();
}
builder.RegisterGeneric(typeof(EfRepository<>)).As(typeof(IRepository<>)).InstancePerHttpRequest();
