實現自動拋棄當前數據庫上下文的模塊。支持各種ORM框架并存
一：OrmContextAutoDisposeModule.cs
EventHandler PostRequestHandlerExecute
MSDN：在 ASP.NET 事件處理程序（例如，某頁或某個 XML Web service）執行完畢時發生。
也就是說注冊這個事件的方法可以做一些頁面執行完畢的清理工作。如果頁面中引入了某個DBContext或者是DataContext，一般情況下這些數據庫資源是需要釋放的，好處很多就不多少了。注冊這個事件，可以在頁面執行完畢時統一進行一些清理的工作。因此程序員在編程的時候也沒有必要做一些using的資源釋放的活了。
namespace MyCompanyName.WebHelpers
{
///<summary>/// 實現自動拋棄當前數據庫上下文的模塊。
///</summary>publicsealedclass OrmContextAutoDisposeModule : IHttpModule
{
#region IHttpModule 成員
public void Init(HttpApplication context)
{
context.PostRequestHandlerExecute += new EventHandler(Enter);
}
public void Dispose()
{
}
#endregion
private void Enter(object sender, EventArgs e)
{
IDictionary httpContextItems = HttpContext.Current.Items;
// 獲取DBContext 或 DataContext 或 ObjectContext
List<object> keys = new List<object>(httpContextItems.Count);
foreach (DictionaryEntry item in httpContextItems)
{
if (item.Value is DataContext || item.Value is ObjectContext || item.Value is DbContext)
{
((IDisposable)item.Value).Dispose();
keys.Add(item.Key);
}
}
foreach (object key in keys)
{
httpContextItems.Remove(key);
}
}
}
}
二.在Web.config文件中注冊Module
<add name="OrmContextAutoDisposeModule" type="MyCompanyName.WebHelpers.OrmContextAutoDisposeModule, MyCompanyName.WebHelpers"/>
</httpModules>
三：OrmContextFactory.cs
{
public static TDataContext GetDataContext<TDataContext>()
where TDataContext : DataContext, new()
{
HttpContext httpContext = HttpContext.Current;
if (httpContext != null)
{
string key = typeof(TDataContext).FullName;
TDataContext dataContext = httpContext.Items[key] as TDataContext;
if (dataContext == null)
{
dataContext = new TDataContext();
httpContext.Items[key] = dataContext;
}
return dataContext;
}
return new TDataContext();
}
public static TObjectContext GetObjectContext<TObjectContext>()
where TObjectContext : ObjectContext, new()
{
HttpContext httpContext = HttpContext.Current;
if (httpContext != null)
{
string key = typeof(TObjectContext).FullName;
TObjectContext objectContext = httpContext.Items[key] as TObjectContext;
if (objectContext == null)
{
objectContext = new TObjectContext();
httpContext.Items[key] = objectContext;
}
return objectContext;
}
return new TObjectContext();
}
public static TDbContext GetDbContext<TDbContext>()
where TDbContext : DbContext, new()
{
HttpContext httpContext = HttpContext.Current;
if (httpContext != null)
{
string key = typeof(TDbContext).FullName;
TDbContext dbContext = httpContext.Items[key] as TDbContext;
if (dbContext == null)
{
dbContext = new TDbContext();
httpContext.Items[key] = dbContext;
}
return dbContext;
}
return new TDbContext();
}
}
浙公網安備 33010602011771號