在ASP.NET中的几个页面之间共享功能的方式

Question

This is possibly very lame question and I lack knowledge about ASP.Net. In this case a link to an article explaining would be very welcome.

I'm working on web-site on ASP.NET with C# as codebehind. My current project involves developing few pages with very similar functionality and a many functions are the same. For example

private void PermissionCheck()
{
    if (null == Session["UserID"] ||
        null == Session["ProjectID"] ||
        null == Session["AssetID"] ||
        null == Session["ProjectName"])
    {
        Response.Redirect("~/Login.aspx");
    }
 }

Would be the same on 2 pages. Some other things are the same as well. I would like to put this into common base class. But there are other functions that don't really belong to pages at all:

private string GetAttachmentTempPath()
{
    return Request.PhysicalApplicationPath + WebConfigurationManager.AppSettings.Get("AttachmentsTempFolder");
}

I would like to move this into Attachment class, but to get the physical path of the application, I need to pass in Request object into that method, which is not really nice, as it couples Attachment class with Page.Request object.

Is there any way to move these functions somewhere else without needing to pass Page.Request objects around??

ps The appliction is huge, and there is no scope to change the entire architecture.

Answer 1

For your permission thing you could make a base page class:

class BasePage : Page
{ 
   ...
   protected override OnInit() {
     // do check here
   }
}

Now you can implement your page like this class MyOtherPage : BasePage { ... } The OnInit gets executed everytime your MyOtherPage gets loaded.

You can see a complete page lifecycle here: Link

For your other problem: Consider to implement a global available static tool class

Update

A good approach for making things like web.config easier to access is a Singleton. In asp.net a singleton is only created once and lives until the asp worker process gets stopped . So this values are shared across the whole asp.net application. This is also good for storing data in a global context that you dont want to get out of your database or file anytime a user makes a page request (for example a version number or things like that)

Update 2

To access the request without passing it to every function, use this:

HttpContext.Current.Request

Answer 2

Base page is a good option for reusable code in Page level. Other than that for things like configuration values it's good to come up with utility classes specifically for those methods base don there type of operations. If you need to avoid passing in Page object into these types of utility methods,

HttpContext

class would be handy because you can access many of the ASP.Net object through static members through this class. HttpConext @ MSDN

Answer 3

If you have similar functions behind the page, you can use ASP.NET WEb User Control .

You can create the functions in the usercontrol and use the control in the pages where necessary.

Have look at this article about Web User Control in Asp.Net