Referenced .Net assembly not found at runtime - asp.net-core-mvc

Here's the scenario.
I created a brand new Asp.Net DNX RC2 Final project. I also added a .Net class library project to my solution (both under FX 4.6.1). The class library project is located in the src folder.
Then, I add a reference to the class library, and it can successfully restore all packages after making changes to the project.json file.
I've added a simple foo function to my class library
namespace ClassLibrary1
{
public class Class1
{
public static string Foo()
{
return "Bar";
}
}
}
and finally in my Home/Index view, I have added the following on top
<div>
#(ClassLibrary1.Class1.Foo())
</div>
The solution compiles with no errors.
You may think so far so good, let's continue.
Then, when I run the solution, the following is shows:
At runtime, my class library is not available.

I ran into a similar situation. In my case I got a RazorEngine exception in Visual Studio which at least gave me an indication of what was going on (it was something like a missing reference exception, even though the class library was added as a reference).
The only way that I could get it working (I'm hoping there is a better way), was to add the following code to my ConfigureServices method in Startup.cs:
services.Configure<RazorViewEngineOptions>(options =>
{
var previous = options.CompilationCallback;
options.CompilationCallback = (context) =>
{
previous?.Invoke(context);
context.Compilation = context.Compilation.AddReferences(MetadataReference.CreateFromFile(typeof(ClassLibrary1.Class1).Assembly.Location));
};
});
I got the idea from the following websites:
Callback on RazorViewEngineOptions
Configure RazorViewEngine
I did confirm that your example is working when I add the code mentioned above.

Related

How to send a form/notification to user from a DLL?

I have a DLL .
And want to send a form/notification to user( who would reference my dll) from this dll.
I just want to build a function inside one class in my dll such that ->, once a user runs his local program and references my dll -> and calls a function that is present in dll -> that particular function should show up a form/notification to user ( from some functionalities in dll )? Is there any other method for the same?
I tried converting the library to a Winform from class library type and that would change its properties into an executable and it would demand presence of the main function. But I am just building a library that can be referenced and when called by the user produces a form at their end?
I tried toast notifications but not .show() method doesnt work inside new ToastContentBuilder() while i call that in a fucntion from my library . Otherwise as an idenpendant console app , it worked fine
Is there a way I can have a project for toast notification in the same solution as that of my library and then call from a class in my main library -> the function present in this different project for toast notif and would produce the toast notification.
You can try the following steps to send a notification to the user from the dll.
First, please create a class library(Target Framework is .NET Core 3.1) called TestDll.
Second, you could install the nuget-package Microsoft.Toolkit.Uwp.Notifications in the class library.
Third, you can add a class and refer to the following code example.
namespace TestDll
{
public class Example
{
public void Setnotifications()
{
new ToastContentBuilder().AddArgument("action", "viewConversation")
.AddArgument("conversationId", 9813)
.AddText("Ev2 Compiler Library")
.AddText("Allow sending build Data to Microsoft")
.AddButton(new ToastButton()
.SetContent("Yes")
.AddArgument("action", "reply")
.SetBackgroundActivation())
.AddButton(new ToastButton()
.SetContent("No")
.AddArgument("action", "like")
.SetBackgroundActivation())
.SetToastScenario(ToastScenario.Reminder)
.Show();
}
}
}
Fourth, please rebuild the class lib and create a console app(Target Framework is .NET Core 3.1).
Fifth, we can add the project reference TestDll to the console app and write the following example in the main method.
static void Main(string[] args)
{
Example example = new Example();
example.Setnotifications();
}
Finally, we can see the notification in the right bottom of computer like the following:
Besides, the problem about 'toast notifications but not .show() method' maybe that you used .net standard framework, you can solve the problem by changing to the .net core framwork.

Microsoft.AspNet.Mvc.Core.pdb not loaded

I have a ASP.NET 5 , MVC 6 project which has reference to a CL in the same solution.
When I try to debug I am unable to enter to the CL's breakpoints.
When I come to the function calling the CL and hit F11 it just continues , so it doesn't enter into the function for debug.
When I debug and get over to the function of the CL and choose "Step into specific" and choose the function it says :
Microsoft.AspNet.Mvc.Core.pdb not loaded.
Microsoft.AspNet.Mvc.Core.pdb contains the debug information required to find the source for the module Microsoft.AspNet.Mvc.Core.dll
Module Information
Version : 6.00.0.10417
Original Location : <path in local disk>
Try one of the following options :
Change existing PDB and binary search paths and retry:
Microsoft Symbbol Servers
So when I try to get it load from microsoft symbol server it says :
Microsoft.AspNet.Mvc.Core.pdb could not be found in the selected paths
My main project is in MVC 6 and my dll is target framework : .Net 4.5.2
I think that due to the beta nature the pdb files are not on the symbol servers. I would assume that after RTM (remember VS is RC but asp.net 5 is very much still beta) they would be added to the symbol servers.
If you need support before that you can clone the asp.net MVC repository (https://github.com/aspnet/Mvc.git) to a location outside your project. Then in the global.json (solution level file) add that path to the project property. This will instruct the compiler to look there for dependency resolution. The compiler will always attempt to resolve dependency using local source over nuget package. In Visual Studio right click on references > restore packages. You should see the package icon change to indicate source. Then you can simply build, and step directly into the source.
This error can be occurred because of a wrong doing in code. I got this error once where I was implementing a base class and overriding its method without a base method call where my db context was initialized. But in my controller I was trying to use the db context which is still not initialized which caused a null reference error. Once I fixed it this error disappeared.
public class MyController : BaseController
{
private MyService _myService;
protected override void Initialize(RequestContext requestContext)
{
//I missed the base call here
//base.Initialize(requestContext);
_myService = new MyService(myDbContext);
}
}
public class BaseController : Controller
{
public MyDbContext myDbContext { get; set; }
protected override void Initialize(RequestContext requestContext)
{
base.Initialize(requestContext);
myDbContext = HttpContext.GetOwinContext().Get<MongoDbContext>();
}
}
Try deleting the bin folder and rebuilding the solution.

Java Binding: The type `...' does not exist in the namespace `...'. Are you missing an assembly?

I am trying to create a Xamarin Java Binding to the Spotify Android SDK. The SDK is now separated into two parts, one for authentication and one for the player. The former java binding works, however, the seconds gives me an error.
The original question was asked on the Xamarin Forums.
Hi,
I am trying to create a binding project for the Spotify Android SDK.
The SDK is seperated into two .aar files. One for authentication and one for media playback (Player).
Firstly I tried having both .aar files in one Binding Project, but the Player.aar was ignored. However, moving it to its own seem to work.
Now, my issue is related to the Java Interface NativePlayerNotificationCallback which is generated to IPlayerNotificationCallback (hence the lack og Notification), but in the Player class it tried to implement: global::Com.Spotify.Android.Player.INativePlayerNotificationCallback.
I can find no other mention of INativePlayerNotificationCallback in the decompiled files. Only IPlayerNotificationCallback.
I understand that this is a bit difficult to imagine. Here are the java class files seen in JD-GUI:
The generated files are listed here:
Inside the file Com.Spotify.Sdk.Android.Player.IPlayerNotificationCallback.cs:
And the error message itself
Error CS0234: The type or namespace name INativePlayerNotificationCallback' does not exist in the namespaceCom.Spotify.Sdk.Android.Player'. Are you missing an assembly reference?
I would really appreciate any insight as to how I can get this to work. It looks to me like there are some inconsistencies in the naming of the interface, but I am not sure.
Thank you for helping out,
Fredrik
Should be fixed by adding metadata to Player binding project:
<metadata>
<attr path="/api/package[#name='com.spotify.sdk.android.player']/interface[#name='NativePlayerNotificationCallback']" name="visibility">public</attr>
</metadata>
and Player class extension (into the Additions directory):
using System.Collections;
using Java.Lang;
using Java.Util.Concurrent;
namespace Com.Spotify.Sdk.Android.Player
{
public partial class Player
{
public IList InvokeAll(ICollection tasks)
{
return null;
}
public IList InvokeAll(ICollection tasks, long timeout, TimeUnit unit)
{
return null;
}
public Object InvokeAny(ICollection tasks)
{
return null;
}
public Object InvokeAny(ICollection tasks, long timeout, TimeUnit unit)
{
return null;
}
}
}
You will probably need to implement these methods correctly by calling generic methods.
Also I had to add metadata to Auth library binding project (I found it in your old topics) and referenced Auth project from Player project as it uses some of the classes (maybe that's no necessary).

Strange MethodMissingException

I have stumbled upon interesting problem which is destroying me last couple of hours. I have project in VS, in references I have library Communication.dll, which contains class Service.
I am invoking following method:
public void ConnectPipe()
{
Service service = new Service();
service.ConnectionMode = ConnectionModes.PIPE;
service.Connect();
}
when I run it, on second line I get MissingMethodException - Method not found: 'Void Service.set_ConnectionMode()'
when I press F12 on service class, I get the Assembly info for the class. When I look for my property, setter is in place, so it does not look like problem with referenced library:
public ConnectionModes ConnectionMode { get; set; }
has anyone any idea where problem might be please?
Had the same issue. Fixed by updating reference to the library.
Point to the exact file on the local, through button "Browse..." don't choose from the library list in references manager - that doesn't work correctly sometimes.
And rebuild the referenced assembly.

Unmanaged Exports (DLLExport) crashes

I'm using RGiesecke DLLExport library to produce a C# DLL that can be dynamically loaded from legacy application built on VC6. It exported methods and they were called from VC6 code. No problems. However, as long as I tried to declare a variable as of any one of my .net classes, it crashed.
//I tried CallingConvention = CallingConvention.StdCall too
[DllExport(CallingConvention = CallingConvention.Winapi)]
static void GetDwgReferences(string fileName)
{
//OK: inialize System classes of .net
DateTime dateTime = DateTime.Now;
//crashing here: declare a variable of my static class (.net assemebly)
//SafeString safeString;
//crashing here: declare a variable of my class (.net assemebly)
//Email email;
//crashing here: initialize an object of my class (.net assemebly)
//DwgXrefs dwgXrefs = new DwgXrefs();
//crashing here by declcare a variable of third-party library (.net assemebly)
//ExSystemServices _serv;
}
What's wrong? Please help.
I had a similar problem here trying to use unmanaged exports with Metatrader to load associated managed dlls.
After some digging I think I have found the problem. The app domain is probably not where you would expect it to be, the CLR is trying to resolve your assembly but failing with a nondescript error. In my case the app domain was actually executing in the directory of the host application, so I assume this is always the case.
What I would suggest you do is build a bare dll with no dependencies, and place in something such as the following:
static void Initialize()
{
SimpleLog.WriteLog("App -" + AppDomain.CurrentDomain.BaseDirectory);
}
[DllExport("Test", CallingConvention = CallingConvention.StdCall)]
public static void Test()
{
Initialize();
}
I am not sure but I think you possibly cannot use a static constructor here?
In the log you should see the executing directory for that domain. If you put your assemblies here it (hopefully) should work. It has fixed the problem for me here. I guess the next question is can we change the domain at runtime as I might not want to put these assemblies here.
Have a google if you need the source code for a simple logger - obviously do not use a third party logging framework with dll dependencies!
I think mine is an adaptation of this one:
http://www.codeproject.com/Articles/80175/Really-Simple-Log-Writer
As the other answer stated, it is difficult to know what error C# is throwing without explicitly catching the error in a try / catch block within each method of a C# dll.
You likely need to export as CallingConvention.StdCall and additionally marshal the incoming string as an unmanaged LPWStr type:
[DllExport(CallingConvention = CallingConvention.StdCall)]
static void GetDwgReferences([MarshalAs(UnmanagedType.LPWStr)] string fileName)
{
}
Please see Code to Export C# DLL to Metatrader Build 600+ for a working example using Robert Giesecke's C# Project Template for Unmanaged Exports to export a C# dll to a legacy application (MT4).
Additionally, you might find Native and .NET Interopability interesting though it is mostly geared toward accessing native code from within .NET.

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