Missing "System.web" reference in ASP.NET - dll

Within my project I have gotten this error:
Error 1 The type or namespace name 'UI' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)
So, basically I attempted to add "system.web" as a reference to my project, but there is no such thing exist in my .NET framework.
How can I install "system.web"?

If the kind of project the reference is being added to is not a web project, then you may need to right click the project and change the target framework from .NET 4 Client to just .NET 4.

In your solution/project, expand the node 'References' & see if there is an icon indicating System.Web is missing. If yes, then right click and add reference.
In the add reference window, click on .NET tab and scroll down to System.Web reference and click on OK.
System.Web is installed as part of .NET Framework. Make sure you have .net framework installed on your machine, if not install it from windows update or from microsoft.com and later open your project to make sure the assembly is referenced.
Hope it helps.

Related

Problem with assembly resolve in xaml (workflow) after update to .NET Framework 4.8

I have an old project with workflow (Appfabric) files in xaml and that project was targeting framework 4.0. We needed to update framework version so we changed the framework to 4.8 and suddenly some of our xaml files stop working.
I could see that there had been no change in the files but still we got errors saying that it can not load some of our custom activity because it could not find files that were in the project.
When looking at the imports it said that Namespace [Namespace.Name] cannot be resolved for those namespace where our custom activity was.
The code for the activity had not change and it was working but somehow the xaml file could not resolve it any more.
The only thing we did was to change the target framework to 4.8 for the project.
I am stuck and wounder if anyone else has had the same problem?
If this is still an issue:
Can you please confirm that the error is coming from AppFabric and
post the full error message
The same
Error Assembly '' can not be resolved. Please add a reference to this assembly in the project that is being built. [Project] [Path].xaml

Xamarin Forms how to consume a wcf service

I've created a Xamarin project which added the following projects to the solution:
Xamarin.UI(Portable)
Xamarin.UI.Droid
Xamarin.UI.iOS
Xamarin.UI.UWP
Xamarin.UI.Windows (Windows 8.1)
Xamarin.UI.WindowsPhone (Windows Phone 8.1)
I am having problems creating a client which can consume my WCF service.
1) Firstly the current Xamarin project template doesn't reference System.ServiceModel assembly in the PCL therefore I cannot right click the PCL and Add Service Reference to my project. When I manually add a reference to System.ServiceModel from this location - C:\Program Files\Reference Assemblies\Microsoft\Framework.NETFramework\v4.5 the menu item for create service reference pops up. When I click Go in the Add Service Reference dialog I get the following error:
"This service cannot be consumed by the current project. Please check if the project target framework supports this service type."
The PCL targets are as follows:
.NET Framework 4.5
ASP.NET Core 1.0
Windows 8
Windows Phone 8.1
Xamarin.Android
Xamarin.iOS
Xamarin.iOS
I don't know how to get this working ?
2) Secondly the work around I use is to create the client with SlSvcUtil.exe
Add the generated code to my PCL along with a reference to System.ServiceModel and everything builds ok. The problem is that when I run the code it flags up type reference errors ! Should I be manually adding the reference to System.ServiceModel anyway? What am I doing wrong in this scenario? Am I missing some steps?
I've checked the Xamarin docs but it seems that I can't find detailed instructions on this.
Please help me out ! Thanks:)
PCL and WCF should be supported. Alternatively, you could get this to work manually with HttpClient, etc. But maybe if you can use the shared project instead of PCL, that would be easier. Otherwise you'd have to also use DependencyService, create interfaces, etc. for each platform.

Issues while upgrading System.Web.Extensions dll reference from 3.5 to 4.0

I need to migrate a website built on .net framework 3.5 to 4.0 and it should work fine in IE9
The solution got upgraded by the VS's version utility and the app compiled successfully. We are using Infragistics UltraWebGrid control v11.1 which is giving some script issue when we try to perform scroll or cell edit. The control has got lot of embedded javascript resource files which seems to be not working fine.
I created a poc website of .net framework 4.0 using the same third party dlls and everything works fine. What I can doubt on is the AJAX part. I tried to consume v4.0 of ajaxcontroltoolkit. But the issue what I am facing is, the toolkit internally references System.Web.Extensions.dll of version 4.0 and my application has many references to the dll of v3.5. Adding the reference to v4.0 doesn't replaces the references to v3.5 in the web.config. Finally I manually updated the version info in web.config which has given birth to other errors.
-Unknown server tag 'asp:ScriptManager','asp:UpdatePanel' etc..
-The type or namespace name 'Script' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)
Please give me some suggestions to upgrade the dll references successfully.
Thanks,
Vaishali

Missing assemblies with mono 3 MVC web app

I've installed the freshly released Mono 3 and MonoDevelop on my Mac, and I was keen to get a simple MVC web application working with razor view pages.
When I File-New-Solution up a MVC 3 Web Application (razor), the thing doesn't compile, giving the error:
The type or namespace GlobalFilterCollection could not be found
It's because 2 references are not working - System.Web.Helpers and System.Web.WebPages. When I look at these in the references list in MonoDevelop, they are red with "Assembly not available" - looking at the references in more detail it seems I'm referencing system.web.mvc 2.0.0.0, whereas everything else is 4.0.0.0. Can anyone advise?
I eventually got mine to run by referencing the System.Web.Mvc.dll found in /Library/Frameworks/Mono.framework/Libraries/mono/4.5/
I also had to bring over System.Web.Helpers.dll from a Windows box and update the Web.Config using one generated by Visual Studio.
There's probably a better way to do this (please be a better way), but figured I'd pass on what I found.
Add packeges "Microsoft ASP.NET MVC" and "Microsoft ASP.NET Web Pages" from NuGet.

Change target framework in VB.NET console app

I created a VB Console app and it defaulted to .NET 4 but I need it to be .NET 3.5. I've been looking but all the references I find say to change it on the 'Compile' tab in properties but I don't have a compile tab or anything else that lets me change the target framework.
Any ideas other than recreating the project?
Note: I'm using VS2010 Ultimate
Update: added screen shot
Are you sure you are right clicking the project, then clicking Properties? For me in the properties window there is a Compile tab on the left side (under Application), and there is an option to change the target under Advanced Compile Options....
In vs2010 you goto PROJECT ---> SLN Name properties --> COMPILE ---> ADVANCED COMPILE OPTIONS(BOTTOM). Now Reverting it to 3.5 is something that as far as I know is something you can't do, atleast not easily or advised. Obviously upgrading from say a 2.0 to a 3.5 or 4.0 framework is easy as the step's above. Your best bet is unfortunately to create a new project in the 3.5 framework.
Project/Properties/Compile/Advanced Compile Options