Using pack Uri with resource from a library - wpf

Support Resource loading in a library, where you have no control over the calling executable.
I do not wish to load files from disk.
How can I fix the ConsoleApp2 code so it supports the described scenario?
Based on the Pack Uri documentation, I was able to do this:
What works
FontLibrary, a Class Library containing only font files with Build Action: Resource
ConsoleApp1, Console Application referencing this FontLibrary.
ConsoleApp1 code
Add reference to WindowsBase runtime assembly.
class Program
{
static void Main(string[] args)
{
// Workaround to register pack://application Uri format
var notUsedButNeeded = System.IO.Packaging.PackUriHelper.UriSchemePack;
var fontFamilies = System.Windows.Media.Fonts.GetFontFamilies(new Uri("pack://application:,,,/"), "/FontLibrary;Component/");
// This correctly lists the font families contained in the font library
Console.WriteLine("Number of font families: " + fontFamilies.Count);
}
}
What doesn't work:
Exception message is
The system cannot find the file specified. (Exception from HRESULT: 0x80070002)'
LogicLibrary, a Class Library referecing FontLibrary
FontLibrary, a Class Library containing only font files with Build Action: Resource
ConsoleApp2, a Console Application referencing LogicLibrary. This represents any consumer of the LogicLibrary, and I cannot add references from this library to the font library, only call LogicLibrary.
ConsoleApp2 code
class Program
{
static void Main(string[] args)
{
new FontLoader().Load();
}
}
LogicLibrary code
public class FontLoader
{
public void Load()
{
// Workaround to register pack://application Uri format
var notUsedButNeeded = System.IO.Packaging.PackUriHelper.UriSchemePack;
// Raises exception when called from ConsoleApp2, since the APPLICATION = the ConsoleApp2 does not reference the font library.
var fontFamilies = System.Windows.Media.Fonts.GetFontFamilies(new Uri("pack://application:,,,/"), "/FontLibrary;Component/");
Console.WriteLine("Number of font families: " + fontFamilies.Count);
}
}
Similar questions:
Using the correct pack:// URI Format

Related

AssemblyLoadContext.Unload does not unload a Wpf Library

I am writing here the same issue posted on Github since I don't see much traffic there recently.
.NET Core Version: 3.1.9 and .Net 5
Windows version: 10.0.18363
Does the bug reproduce also in WPF for .NET Framework 4.8?: AssemblyLoadContext not supported
I am trying to load and unload on demand a Wpf App library (and all the related dependencies). Everything works, but none of the assemblies get unloaded when calling the Unload method.
If I replace the Wpf library with a .Net Core library containing a few sample methods, I can see the library removed from VS Modules window after a couple of GC iterations.
If I'm not wrong I should expect AssemblyLoadContext to load WpfLibrary and related dependencies (PresentationCore, PresentationFramework etc), but WpfLibrary is the only one loaded. All the other dependencies seems be loaded in the default context. May be that I misunderstood how it works, but to me seems that the framework dependencies prevent the unloading.
Also I am not sure if the problem I am reporting is related to this and/or this.
I attached a sample project which is structured like this:
Project 1 (MainApp, a console project with added System.Windows.Forms reference to enable message pump)
class Program
{
class WpfAppAssemblyLoadContext : AssemblyLoadContext
{
public WpfAppAssemblyLoadContext() : base(true) { }
protected override Assembly Load(AssemblyName assemblyName) => null;
}
[MethodImpl(MethodImplOptions.NoInlining),]
public static void TestRun()
{
var context = new WpfAppAssemblyLoadContext();
var assembly = context.LoadFromAssemblyPath($"{Environment.CurrentDirectory}\\WpfLibrary.dll");
var inst = (IProxy) assembly.CreateInstance("WpfLibrary.MainWindow");
inst.ShowWindow();
inst.CloseWindow();
context.Unload();
assembly = null;
context = null;
inst = null;
}
[STAThread,]
static void Main(string[] args)
{
TestRun();
for (var i = 0; i < 100; i++) {
GC.Collect();
GC.WaitForPendingFinalizers();
}
Application.Run();
}
}
Project 2 (ProxyInterface)
namespace ProxyInterface
{
public interface IProxy
{
void ShowWindow();
void CloseWindow();
}
}
Project 3 (a regular wpf library with implementation of interface in Project 2 )
namespace WpfLibrary
{
public partial class MainWindow : Window, IProxy
{
public MainWindow()
{
InitializeComponent();
}
public void ShowWindow() { Show();}
public void CloseWindow() { Close();}
}
}
UnloadWpfLibrary.zip
(Solution file inside "MainApp" folder)
Further updates:
DotNet team added the issue to "Future Milestone", therefore I have to deduce that they recognized this as a bug. I have no idea on when we will see Wpf working with AssemblyLoadContext.
Seems to be that there is a workaround which involve splitting the target assembly into two separate assemblies. I attached the project with the suggested modifications and this time one of the two assemblies is unloaded, but all of the others are still loaded included WpfLibrary.
UnloadWpfLibraryWithWorkaround.zip
I think that for me it's time to give up and recur to IPC (named pipes) although I am not sure if this could be a valid replacement.
May be I missed something and someone more expert can do further progress and attach here the project with the correct modifications, it would be of great benefit for all the users that want to use ALC to load and unload WPF.
It would be a total of 4 projects just to load and unload a wpf assembly on demand and this is not exactly clean, but if the final result is the same it would be acceptable.

MEF can't find module's views when dll in subdirectory

I try to make a little application with Prism and MEF in order to learn how it works. I'm stuck on a fairly frustrating problem.
I would like to have a "Modules" subdirectory in my base app directory where I copy all the module's dll as a post build event.
These modules are MVVM app with View and ViewModel.
My problem is : When I copy my module's dll in the main app directory, the views are displayed in the shell, but when my modules are in the subdirectory, nothing is displayer.
My modules and their parts are found but according to fuslogvw the views can't be found :
* Assembly Binder Log Entry (27/11/2015 # 16:45:28) *
The operation failed.
Bind result: hr = 0x80070002. The system cannot find the file specified.
Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Running under executable C:\Users\mouarf\Downloads\Prism-Samples-Wpf-master\Prism-Samples-Wpf-master\HelloWorld\HelloWorld\bin\Debug\HelloWorld.vshost.exe
--- A detailed error log follows.
=== Pre-bind state information ===
LOG: DisplayName = ModuleB.resources, Version=1.0.0.0, Culture=en-US, PublicKeyToken=null
(Fully-specified)
LOG: Appbase = file:///C:/Users/mouarf/Prism/HelloWorld/bin/Debug/
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = HelloWorld.vshost.exe
Calling assembly : ModuleB, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in LoadFrom load context.
WRN: Native image will not be probed in LoadFrom context. Native image will only be probed in default load context, like with Assembly.Load().
LOG: Using application configuration file: C:\Users\mouarf\Downloads\Prism-Samples-Wpf-master\Prism-Samples-Wpf-master\HelloWorld\HelloWorld\bin\Debug\HelloWorld.vshost.exe.Config
LOG: Using host configuration file:
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/Users/mouarf/Prism/HelloWorld/bin/Debug/en-US/ModuleB.resources.DLL.
LOG: Attempting download of new URL file:///C:/Users/mouarf/Prism/HelloWorld/bin/Debug/en-US/ModuleB.resources/ModuleB.resources.DLL.
LOG: Attempting download of new URL file:///C:/Users/mouarf/Prism/HelloWorld/bin/Debug/en-US/ModuleB.resources.EXE.
LOG: Attempting download of new URL file:///C:/Users/mouarf/Prism/HelloWorld/bin/Debug/en-US/ModuleB.resources/ModuleB.resources.EXE.
LOG: Attempting download of new URL file:///C:/USERS/Mouarf/PRISM/HELLOWORLD/BIN/DEBUG/MODULES/en-US/ModuleB.resources.DLL.
LOG: Attempting download of new URL file:///C:/USERS/Mouarf/PRISM/HELLOWORLD/BIN/DEBUG/MODULES/en-US/ModuleB.resources/ModuleB.resources.DLL.
LOG: Attempting download of new URL file:///C:/USERS/Mouarf/PRISM/HELLOWORLD/BIN/DEBUG/MODULES/en-US/ModuleB.resources.EXE.
LOG: Attempting download of new URL file:///C:/USERS/Mouarf/PRISM/HELLOWORLD/BIN/DEBUG/MODULES/en-US/ModuleB.resources/ModuleB.resources.EXE.
LOG: All probing URLs attempted and failed.
I don't know why MEF look in "modules\en-US\", I think it's probably why it doesn't find any views, but I couldn't find how to specify otherwise.
My bootstrapper :
public class Bootstrapper : MefBootstrapper
{
protected override void ConfigureAggregateCatalog()
{
base.ConfigureAggregateCatalog();
this.AggregateCatalog.Catalogs.Add(new AssemblyCatalog(typeof(Bootstrapper).Assembly));
string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Modules");
DirectoryCatalog catalog = new DirectoryCatalog(path, "*.dll");
this.AggregateCatalog.Catalogs.Add(catalog);
}
protected override DependencyObject CreateShell()
{
return this.Container.GetExportedValue<MainWindow>();
}
protected override void InitializeShell()
{
base.InitializeShell();
Application.Current.MainWindow = (MainWindow)this.Shell;
Application.Current.MainWindow.Show();
}
protected override void ConfigureContainer()
{
base.ConfigureContainer();
}
protected override IModuleCatalog CreateModuleCatalog()
{
return new ConfigurationModuleCatalog();
}
}
My modules :
[ModuleExport(typeof(ModuleAModule))]
public class ModuleAModule : IModule
{
IRegionManager _regionManager;
[ImportingConstructor]
public ModuleAModule(IRegionManager regionManager)
{
_regionManager = regionManager;
}
public void Initialize()
{
_regionManager.RegisterViewWithRegion(RegionNames.RightRegion, typeof(ViewA));
}
}
My views :
/// <summary>
/// Interaction logic for ViewA.xaml
/// </summary>
[Export]
public partial class ViewA : UserControl
{
public ViewA()
{
InitializeComponent();
}
}
My viewmodels :
[Export]
public class ViewAViewModel : BindableBase
{
private string _title = "Module A";
public string Title
{
get { return _title; }
set { SetProperty(ref _title, value); }
}
}
Anyone ?
Edit :
Here's the solution for who whould like to take a look : HelloWorldPrismMef
Edit 2 :
The investigation still goes on, I discovered the really handy mefx ! So my problem seems to be :
[Part] ModuleA.ModuleAModule from: DirectoryCatalog (Path="Modules")
[Primary Rejection]
[Export] ModuleA.ModuleAModule (ContractName="Prism.Modularity.IModule")
[Import] ModuleA.ModuleAModule..ctor (Parameter="regionManager", ContractName="Prism.Regions.IRegionManager")
[Exception] System.ComponentModel.Composition.ImportCardinalityMismatchException: No exports were found that match the constraint contract name
ContractName Prism.Regions.IRegionManager
RequiredTypeIdentity Prism.Regions.IRegionManager n'a été trouvée.
at System.ComponentModel.Composition.Hosting.ExportProvider.GetExports(ImportDefinition definition, AtomicComposition atomicComposition)
at Microsoft.ComponentModel.Composition.Diagnostics.CompositionInfo.AnalyzeImportDefinition(ExportProvider host, IEnumerable`1 availableParts, ImportDefinition id)
Does that mean that I need to Export a IRegionManager class ?
The log you have posted is for an attempt to load a resource .dll, something that MEF will never load (resource .dlls are used to store application resource information, like strings for internationalization). You should look for errors that do not mention resource .dlls.
Also, it seems to me you are attempting to edit the Prism Library HelloWorld example from GitHub. This particular example has tight coupling with ModuleA (by that I mean that ModuleA is used as a project dependency in HelloWorld) and to my knowledge you can not simply move the ModuleA.dll from the main folder to a modules folder and expect it to work.
My suggestion would be to add a new project, set that to output to a modules folder and see if that loads (leaving the ModuleA project alone). Or you could remove the reference from the HelloWorld project and use the post build event.
Now regarding the loading of modules from a directory, in my humble opinion, you are over complicating it. All you need is
AgregateCatalog.Catalogs.Add(new DirectoryCatalog(#".\Modules"));
Or presuming you have a convention that specifies a pattern for module file names that resembles AppName.Modules.[ModuleNameHere].dll (eg: AppName.Modules.LoginModule.dll you could use something like this to load the modules
AgregateCatalog.Catalogs.Add(new DirectoryCatalog(#".\Modules", "AppName.Modules.*Module.dll"));
Although this does not seem the case here, if you ever try to load modules from a zone deemed as untrustworthy, the default security policy is to ignore the module. This would happen if you attempt to run the application over a network connection like Windows Share. For this scenario you need to add these instructions to App.config
<runtime>
<loadFromRemoteSources enabled="true" />
</runtime>
These should be added after <startup /> section.
Hope this helps you.
Edit:
Does that mean that I need to Export a IRegionManager class ?
No, that's just complaining because mefx has not loaded the assembly that exports it (Prism.Wpf.dll I think it is called).
Personally I found mefx.exe to be cumbersome; I prefer the GUI version
Now regarding your code, I took a look at the GitHub repository and made some changes but not that many (had some issues with references with ModuleC so I had to remove and add again Prism.Mef & company):
Removed the PostBuildEvent from Infrastructure project
Changed the PostBuildEvent from the module projects. This needs some explaining:
all macros come appended with the directory delimiter "\" so you do not need to add it (I am reffering to $(OutDir)\Modules => $(OutDir)Modules).
COPY/XCOPY require the destination path to end with a delimiter or the destination path will be intepreted as a destinaiton directory ( $(OutDir)Modules => *$(OutDir)Modules* ).
Destination directory needs to exist (so first command should be MKDIR)
I also commented (lines that start with REM are comments) out the command that copies the .pdb because I do not think it is needed and added the /z flag to XCOPY.
Added ILoggerFacade as a dependency to demonstrate that the modules actually load. If you run the application from the Visual Studio Debugger, you will see some messages in the debug window.
Added <loadFromRemoteSources enabled="true" /> in App.config => <configuration /> => <runtime /> so I can run the app over a mounted partition where the project is stored.
All of this is in the PR.
Now regarding why it will not auto-display the views in the regions, I can not say yet. I will keep investigating during my free time, but you might have better luck asking Brian Lagunas as he is one of the developers of Prism.
Edit 2:
As I was looking at Brian Lagunas's profile I saw he answered this post that luckily solves the issue.
Will also add a PR to GitHub.

Nancy fails to find static content in custom convention

I've set up a Nancy bootstrapper to serve static content from a non-default directory path (it's self hosted Nancy).
Strangely, the following works for the custom View location convention but not either of the js or css static content conventions (and yes, both files and folders exist at these locations!). My attempts at trying to resolve this are further compounded as I haven't figured out how to log errors which occur when static content is not found.
using System;
using System.IO;
using Nancy;
using Nancy.Conventions;
using Nancy.Bootstrapper;
using Nancy.TinyIoc;
namespace MyApp
{
public class ApplicationBootstrapper : DefaultNancyBootstrapper
{
private const string RELATIVE_PATH_TO_SOURCE = #"../static/MyApp/";
protected override void ConfigureConventions(NancyConventions nancyConventions)
{
nancyConventions.StaticContentsConventions.Add(StaticContentConventionBuilder.AddDirectory("js", string.Concat(RELATIVE_PATH_TO_SOURCE, "Scripts/")));
nancyConventions.StaticContentsConventions.Add(StaticContentConventionBuilder.AddDirectory("css", string.Concat(RELATIVE_PATH_TO_SOURCE, "Content/")));
this.Conventions.ViewLocationConventions.Add((viewName, model, context) =>
{
return string.Concat(RELATIVE_PATH_TO_SOURCE, "Views/", viewName);
});
this.Conventions.ViewLocationConventions.Add((viewName, model, context) =>
{
return string.Concat(RELATIVE_PATH_TO_SOURCE, "Views/", context.ModuleName, "/", viewName);
});
base.ConfigureConventions(nancyConventions);
}
protected override IRootPathProvider RootPathProvider
{
get
{
return new MyRootPathProvider();
}
}
protected override void ApplicationStartup(TinyIoCContainer container, IPipelines pipelines)
{
pipelines.OnError += (ctx, ex) =>
{
Console.WriteLine("RootPath : {0}", DebugRootPathProvider.RootPath);
Console.WriteLine("Unhandled error on request: {0} : {1}", ctx.Request.Url, ex.Message); //HACK
Console.WriteLine(ex.StackTrace); //HACK poor man's logging
return null;
};
}
}
public class MyRootPathProvider : IRootPathProvider
{
public static readonly string RootPath;
static MyRootPathProvider()
{
RootPath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
}
public string GetRootPath()
{
return RootPath;
}
}
}
The output from Chrome and ProcMon is as follows:
How should I:
Log errors occurring with not found js and css files?
Resolve the 404 errors with the static file conventions?
Instead of logging you can use sysinternals process monitor and look for what files the nancy process (exe or IIS worker process) are attempting to read.
I had problems with serving static files (in my case js files) in a self host environment as well. They were not recognized at all, not even in the default "Content" folder. My solution: I installed the Microsoft StaticFiles NuGet Package.
In the startup class, register a static files folder like this:
public class Startup
{
public void Configuration(IAppBuilder app)
{
app.UseStaticFiles("/Scripts");
app.MapSignalR();
app.UseNancy();
}
}
This way, all files and subfolders in the "Scripts" folder are served as static files. There is also an overload of the UseStaticFiles() function that lets you map a physical path to a virtual path.
Important here: the call to UseNancy() has to be the very last, otherwise everything after it won't work. I also tried to combine it with SignalR, as you can see above, and there the UseNancy() call had to be at the end as well.

Registering Startup Class In Nancy Using AutoFac Bootstrapper

I've been reading through a lot of the Jabbr code to learn Nancy and trying to implement many of the same patterns in my own application. One of the things I can't seem to get working is the concept of an on application start class. The Jabbr code base has an App_Start folder with a Startup.cs file (here) in it with the following implementation.
public partial class Startup
{
public void Configuration(IAppBuilder app)
{
...
SetupNancy(kernel, app);
...
}
}
private static void SetupNancy(IKernel kernel, IAppBuilder app)
{
var bootstrapper = new JabbRNinjectNancyBootstrapper(kernel);
app.UseNancy(bootstrapper);
}
When I tried to do something similar to that in my project the Startup.cs file was just ignored. I searched the Jabbr code base to see if it was used anywhere but I wasn't able to find anything and the only differences I could see is Jabbr uses Ninject while I wanted to use AutoFac
Is there a way to register a startup class in nancy?
Take a look at my project over on GitHub, you'll be interested in the Spike branch and may have to unload the ChainLink.Web project to run I can't remember.
I had some trouble finding a way to configure the ILifetimeScope even after reading the accepted answer here by TheCodeJunkie. Here's how you do the actual configuration:
In the bootstrapper class derived from the AutofacNancyBootstrapper, to actually configure the request container, you update the ILifetimeScope's component registry.
protected override void ConfigureRequestContainer(
ILifetimeScope container, NancyContext context)
{
var builder = new ContainerBuilder();
builder.RegisterType<MyDependency>();
builder.Update(container.ComponentRegistry);
}
The application container can be updated similarly in the ConfigureApplicationContainer override.
You should install the Nancy.Bootstrappers.Autofac nuget, inherit from the AutofacNancyBootstrapper type and override the appropriate method (depending on your lifetime scope requirements: application or request). For more info check the readme file https://github.com/nancyfx/nancy.bootstrappers.autofac
HTH
After following the advice from TheCodeJunkie you can use the Update method on the ILifetimeScope container parameter which gives you a ContainerBuilder through an Action:
protected override void ConfigureRequestContainer(ILifetimeScope container, NancyContext context)
{
container.Update(builder =>
{
builder.RegisterType<MyType>();
});
}

Enterprise Library 5: Creating instances of Enterprise Library objects

I am using Enterprise Library 5.0 in my win-form Application.
1. Regarding creating instances of Enterprise Library objects
What is the best way to Resolve the reference for Logging / exception objects? In our application, we have different applications in solution. So Solutions have below project:
CommonLib (Class Lib)
CustomerApp (winform app)
CustWinService (win service proj)
ClassLib2 (class Lib)
I have implemented logging / exceptions as below in CommonLib project. Created a class AppLog as below:
public class AppLog
{
public static LogWriter defaultWriter = EnterpriseLibraryContainer.Current.GetInstance<LogWriter>();
public static ExceptionManager exManager = EnterpriseLibraryContainer.Current.GetInstance<ExceptionManager>();
public AppLog()
{
}
public static void WriteLog(string LogMessage, string LogCategories)
{
// Create a LogEntry and populate the individual properties.
if (defaultWriter.IsLoggingEnabled())
{
string[] Logcat = LogCategories.Split(",".ToCharArray());
LogEntry entry2 = new LogEntry();
entry2.Categories = Logcat;
entry2.EventId = 9007;
entry2.Message = LogMessage;
entry2.Priority = 9;
entry2.Title = "Logging Block Examples";
defaultWriter.Write(entry2);
}
}
}
And then I used Applog class as below for logging and exception in different projects:
try
{
AppLog.WriteLog("This is Production Log Entry.", "ExceCategory");
string strtest = string.Empty;
strtest = strtest.Substring(1);
}
catch (Exception ex)
{
bool rethrow = AppLog.exManager.HandleException(ex, "ExcePolicy");
}
So its the correct way to use Logging and Exception? or any other way i can improve it?
2. Logging File Name dynamic
In logging block, we have fileName which need to be set in app.config file. Is there a way I can assign fileName value dynamically through coding? Since I don't want to hard code it in config file and paths are different for production and development environment.
Thanks
TShah
To keep your application loosely coupled and easier to test, I would recommend defining separate logging and exception handling interfaces, then having your AppLog class implement both. Your application can then perform logging and exception handling via those interfaces, with AppLog providing the implementation.
You can have a different file name set per environment using config transforms, which I believe you can use in a winforms application by using Slow Cheetah.

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