Save the URL on which a user currently browses each time from the whole website.

Save the URL on which a user currently browses each time from the whole website.

Here are some step-by-step process on how to implement the example using an action filter to log the URL in an ASP.NET MVC application:

Step 1: Create the LogUrlAttribute class
Create a new class called `LogUrlAttribute` and inherit from `ActionFilterAttribute`. This class will contain the logic to log the URL.

```csharp
using System.Web.Mvc;

public class LogUrlAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        var request = filterContext.HttpContext.Request;
        string url = request.RawUrl;

        // Perform logging or other actions with the URL

        base.OnActionExecuting(filterContext);
    }
}
```

Step 2: Apply the LogUrlAttribute to action methods or controllers
Apply the `[LogUrl]` attribute to the action methods or controllers where you want to log the URL. You can apply it to individual action methods or to the entire controller.

```csharp
[LogUrl]
public ActionResult Index()
{
    // Action method logic
}
```

Step 3: Register the global action filter
To ensure that the `LogUrlAttribute` is applied to all appropriate action methods throughout your application, you need to register it as a global action filter in the `FilterConfig.cs` file.

In your `FilterConfig.cs` file (located in the `App_Start` folder), add the following code:

```csharp
public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new LogUrlAttribute());
        
        // Add other global filters if needed
        
        // Remaining code
    }
}
```

Step 4: Enable global filters in Global.asax
In the `Global.asax.cs` file, ensure that the `RegisterGlobalFilters` method from `FilterConfig.cs` is called during application startup. By default, this method is called in the `Application_Start` method.

```csharp
protected void Application_Start()
{
    // Other code

    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);

    // Remaining code
}
```

That's it! With these steps, the `LogUrlAttribute` will be applied to the specified action methods or controllers, and the `OnActionExecuting` method will be executed before each action method is called. You can perform logging or any other desired actions with the URL within the `OnActionExecuting` method.

Note that this example assumes you're using ASP.NET MVC and the traditional `Global.asax` file. If you're using ASP.NET Core, the process is slightly different, but the concept of action filters still applies.