Is there any way to check if a resource exists in an assembly without having to use exception handling? I'm currently loading images from several assemblies, and if they don't exist then I'm handling the IOException, which causes quite a bit of overhead.
Would something like this work for you?
// Member Variable
string [] resourceNames;
// Function
Boolean ResourceExists(string resourceName)
{
if (resourceNames == null)
{
resourceNames =
Assembly.GetExecutingAssembly().GetManifestResourceNames();
}
return resourceNames.Contains(resourceName);
}
Copied answer from here:
public static bool ResourceExists(string resourcePath)
{
var assembly = Assembly.GetExecutingAssembly();
return ResourceExists(assembly, resourcePath);
}
public static bool ResourceExists(Assembly assembly, string resourcePath)
{
return GetResourcePaths(assembly)
.Contains(resourcePath);
}
public static IEnumerable<object> GetResourcePaths(Assembly assembly)
{
var culture = System.Threading.Thread.CurrentThread.CurrentCulture;
var resourceName = assembly.GetName().Name + ".g";
var resourceManager = new ResourceManager(resourceName, assembly);
try
{
var resourceSet = resourceManager.GetResourceSet(culture, true, true);
foreach(System.Collections.DictionaryEntry resource in resourceSet)
{
yield return resource.Key;
}
}
finally
{
resourceManager.ReleaseAllResources();
}
}
Related
I have created a new domain, then loaded the assembly into this domain, but when GetTypes() gives an error like the picture attached, hope everyone helps, thanks.
Code
public class Program
{
public static void Main()
{
string assemblyPath = #"D:\Github\BeyConsPlugin\BeyConsProject\bin\x64\Debug\BeyConsRevitProject.dll";
AppDomain appDomain = CreateChildDomain(AppDomain.CurrentDomain, Guid.NewGuid().ToString());
appDomain.AssemblyResolve += AssemblyResolve;
var value = (Proxy)appDomain.CreateInstanceAndUnwrap(typeof(Proxy).Assembly.FullName, typeof(Proxy).FullName);
var assembly = value.GetAssembly(assemblyPath);
var types = assembly.GetTypes();
Console.ReadKey();
}
private static Assembly AssemblyResolve(object sender, ResolveEventArgs args)
{
AssemblyName assemblyName = new AssemblyName(args.Name);
string dependentAssemblyFilename = Path.Combine(#"D:\Github\BeyConsPlugin\BeyConsProject\bin\x64\Debug", assemblyName.Name + ".dll");
if (File.Exists(dependentAssemblyFilename)) return null;
return Assembly.LoadFile(dependentAssemblyFilename);
}
public static AppDomain CreateChildDomain(AppDomain parentDomain, string domainName)
{
Evidence evidence = new Evidence(parentDomain.Evidence);
AppDomainSetup setup = parentDomain.SetupInformation;
return AppDomain.CreateDomain(domainName, evidence, setup);
}
}
public class Proxy : MarshalByRefObject
{
public Assembly GetAssembly(string assemblyPath)
{
try
{
return Assembly.LoadFile(assemblyPath);
}
catch { return null; }
}
}
Error
Have you checked if BeyConsRevitProject.dll assembly is in the bin directory of your application? This is a possible cause. Try deleting the bin/ and obj/ folders and rebuilding your solution, if the error persists, use this code below to ascertain the real reason for the error:
using System.IO;
using System.Reflection;
using System.Text;
try
{
//The code that causes the error goes here.
}
catch (ReflectionTypeLoadException ex)
{
StringBuilder sb = new StringBuilder();
foreach (Exception exSub in ex.LoaderExceptions)
{
sb.AppendLine(exSub.Message);
FileNotFoundException exFileNotFound = exSub as FileNotFoundException;
if (exFileNotFound != null)
{
if(!string.IsNullOrEmpty(exFileNotFound.FusionLog))
{
sb.AppendLine("Fusion Log:");
sb.AppendLine(exFileNotFound.FusionLog);
}
}
sb.AppendLine();
}
string errorMessage = sb.ToString();
//Display or log the error based on your application.
}
This code was suggested by Ben Gripka here:
Error message 'Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.'
I need to load .dll(plugins) in another domain. In main app I don't know anything about plugins types, only that they implement common interface ICommonInterface with some methods. So this code wouldn't help, because I can't create an instance with interface type.
AppDomain domain = AppDomain.CreateDomain("New domain name");
//Do other things to the domain like set the security policy
string pathToDll = #"C:\myDll.dll"; //Full path to dll you want to load
Type t = typeof(TypeIWantToLoad);
TypeIWantToLoad myObject = (TypeIWantToLoad)domain.CreateInstanceFromAndUnwrap(pathToDll, t.FullName);
My question is how I can load assembly in new domain and get the instance, if I know only interface name which implements type I want to create.
UPDATE:
Here is my code:
MainLib.dll
namespace MainLib
{
public interface ICommonInterface
{
void ShowDllName();
}
}
PluginWithOutException.dll
namespace PluginWithOutException
{
public class WithOutException : MarshalByRefObject, ICommonInterface
{
public void ShowDllName()
{
Console.WriteLine("PluginWithOutException");
}
}
}
PluginWithException.dll
namespace PluginWithException
{
public class WithException : MarshalByRefObject, ICommonInterface
{
public void ShowDllName()
{
Console.WriteLine("WithException");
throw new NotImplementedException();
}
}
}
And main application:
static void Main(string[] args)
{
string path = #"E:\Plugins\";
string[] assemblies = Directory.GetFiles(path);
List<string> plugins = SearchPlugins(assemblies);
foreach (string item in plugins)
{
CreateDomainAndLoadAssebly(item);
}
Console.ReadKey();
}
public static List<string> SearchPlugins(string[] names)
{
AppDomain domain = AppDomain.CreateDomain("tmpDomain");
domain.Load(Assembly.LoadFrom(#"E:\Plugins\MainLib.dll").FullName);
List<string> plugins = new List<string>();
foreach (string asm in names)
{
Assembly loadedAssembly = domain.Load(Assembly.LoadFrom(asm).FullName);
var theClassTypes = from t in loadedAssembly.GetTypes()
where t.IsClass &&
(t.GetInterface("ICommonInterface") != null)
select t;
if (theClassTypes.Count() > 0)
{
plugins.Add(asm);
}
}
AppDomain.Unload(domain);
return plugins;
}
Plugins and main app have reference to MainLib.dll. The main aim is to not to load assemblies in default domain, but load them to another domains, so when I don't need them, I just Unload() domain and unload all plugins from application.
For now the exception is FileNotFoundException, Could not load file or assembly 'PluginWithException, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.) on string Assembly loadedAssembly = domain.Load(Assembly.LoadFrom(asm).FullName);(I trying to load plugin with name PluginWithException), I've delete all the dependencies in plugins, exept System, I loaded System.dll in this domain(it loaded correct and it is in domain), but still cant load plugins into domain. Also I checked, that PluginWithException has 2 dependencies - mscorlib and MainLib, and all of them loaded to this domain.
UPDATE: Here I asked this question with more details.
I'm not sure if it's what you need, i'd try to help you with this.
This is how I do to load plugin assemblies. I use a helper class to manage new AppDomain and the instance of the class on that assembly. This is the helper class:
[Serializable, ClassInterface(ClassInterfaceType.AutoDual)]
class helperDomain<T>: MarshalByRefObject where T: class
{
#region private
private AppDomain _app_domain;
private AppDomainSetup _app_domain_info;
private string _assembly_class_name;
private string _assembly_file;
private string _assembly_file_name;
private T _inner_class;
private bool _load_ok;
private string _loading_errors;
private string _path;
#endregion
#region .ctor
public helperDomain(string AssemblyFile,
string configFile = null, string domainName)
{
this._load_ok = false;
try
{
this._assembly_file = AssemblyFile; //full path to assembly
this._assembly_file_name = System.IO.Path.GetFileName(this._assembly_file); //assmbly file name
this._path = System.IO.Path.GetDirectoryName(this._assembly_file); //get root directory from assembly path
this._assembly_class_name = typeof(T).ToString(); //the class name to instantiate in the domain from the assembly
//start to configure domain
this._app_domain_info = new AppDomainSetup();
this._app_domain_info.ApplicationBase = this._path;
this._app_domain_info.PrivateBinPath = this._path;
this._app_domain_info.PrivateBinPathProbe = this._path;
if (!string.IsNullOrEmpty(configFile))
{
this._app_domain_info.ConfigurationFile = configFile;
}
//lets create the domain
this._app_domain = AppDomain.CreateDomain(domainName, null, this._app_domain_info);
//instantiate the class
this._inner_class = (T) this._app_domain.CreateInstanceFromAndUnwrap(this._assembly_file, this._assembly_class_name);
this._load_ok = true;
}
catch (Exception exception)
{
//There was a problema setting up the new appDomain
this._load_ok = false;
this._loading_errors = exception.ToString();
}
}
#endregion
#region public properties
public string AssemblyFile
{
get
{
return _assembly_file;
}
}
public string AssemblyFileName
{
get
{
return _assembly_file_name;
}
}
public AppDomain AtomicAppDomain
{
get
{
return _app_domain;
}
}
public T InstancedObject
{
get
{
return _inner_class;
}
}
public string LoadingErrors
{
get
{
return _loading_errors;
}
}
public bool LoadOK
{
get
{
return _load_ok;
}
}
public string Path
{
get
{
return _path;
}
}
#endregion
}
and then load plugins (each in a diferent folder).
foreach(string pluginassemblypath in pluginspaths)
{
//Each pluginassemblypath (as it says..) is the full path to the assembly
helperDomain<IPluginClass> isoDomain =
helperDomain<IPluginClass>(pluginassemblypath,
pluginassemblypath + ".config",
System.IO.Path.GetFileName(pluginassemblypath) + ".domain");
if (isoDomain.LoadOK)
{
//We can access instance of the class (.InstancedObject)
Console.WriteLine("Plugin loaded..." + isoDomain.InstancedObject.GetType().Name);
}
else
{
//Something happened...
Console.WriteLine("There was en error loading plugin " +
pluginassemblypath + " - " + helperDomain.LoadingErrors);
}
}
Hope it will helps you...
This question seems relevant to what you want to do.
How to Load an Assembly to AppDomain with all references recursively?
After you've loaded the assembly, you can use Assembly.GetTypes() and iterate to find the types that implement your interface.
I'm currently using the following method to check for test assemblies:
private bool IsTestAssembly(string path)
{
var assembly = Assembly.LoadFrom(path);
foreach (var type in assembly.GetTypes())
{
var a = type.GetCustomAttributes(true).Select(x => x.ToString());
if (a.Contains("Microsoft.VisualStudio.TestTools.UnitTesting.TestClassAttribute"))
return true;
}
return false;
}
But I would like to check this without loading the assembly in memory because I need to be able to delete it afterwards in case the verification fails.
I was hoping I could simply unload the assembly, but I soon discovered that, according to MSDN:
There is no way to unload an individual assembly without unloading all of the application domains that contain it.
Thanks in advance!
I worked out a short solution as suggested by TheGreatCO, i.e. to load the assembly in a new AppDomain:
1) Usage:
// assemblies are unloaded on disposal
using (var analyser = new AssemblyAnalyser())
{
var path = "my.unit.tests.dll";
var b = analyser.IsTestAssembly(path);
Assert.IsTrue(b);
}
2) Implementation:
public class AssemblyAnalyser : MarshalByRefObject, IDisposable
{
public AssemblyAnalyser()
{
var evidence = new Evidence(AppDomain.CurrentDomain.Evidence);
var appSetup = new AppDomainSetup()
{
ApplicationBase = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)
};
appDomain = AppDomain.CreateDomain(otherDomainFriendlyName, evidence, appSetup);
}
public bool IsTestAssembly(string assemblyPath)
{
if (AppDomain.CurrentDomain.FriendlyName != otherDomainFriendlyName)
{
var analyser = appDomain.CreateInstanceAndUnwrap(Assembly.GetExecutingAssembly().FullName, GetType().FullName);
return ((AssemblyAnalyser)analyser).IsTestAssembly(assemblyPath);
}
else
{
var assembly = Assembly.LoadFrom(assemblyPath);
return ContainsTestClasses(assembly);
}
}
public void Dispose()
{
if (AppDomain.CurrentDomain.FriendlyName != otherDomainFriendlyName)
{
AppDomain.Unload(appDomain);
GC.SuppressFinalize(this);
}
}
~AssemblyAnalyser()
{
Dispose();
}
private bool ContainsTestClasses(Assembly assembly)
{
foreach (var type in assembly.GetTypes())
{
var attr = type.GetCustomAttributes(true).Select(x => x.ToString());
if (attr.Contains("Microsoft.VisualStudio.TestTools.UnitTesting.TestClassAttribute"))
return true;
}
return false;
}
private const string otherDomainFriendlyName = "AssemblyAnalyser";
private AppDomain appDomain;
}
Inspect the assemblies using Mono.Cecil. Cecil does not need to load the assembly to inspect it.
I have a requirement to dynamically load and cast an instance of a class to it's various base types using requirement. Now on reading and trying my hand on some examples, I find that either I probably don't understand all that I need to when it comes to working with classes at runtime.
I have a situation where Abstract class B implements interface A. Now Class B is a base class for class C. When I dynamically load, at runtime, the assembly that contains all 3 types, I expect that I should be able to, using Load From context, load the assembly, create an instance of class C, and cast it to type of interface A. But that does not seem to be happening at all and I would appreciate an explanation as to why. Thanks in Advance.
http://msdn.microsoft.com/en-us/library/2xkww633.aspx
http://msdn.microsoft.com/en-us/library/1009fa28.aspx
public interface ICaseOutputGenerator
{
String SampleProperty { get; set; }
void Process();
}
public abstract class CaseOutputGeneratorBase : ICaseOutputGenerator
{
public String SecondSampleProperty { get; set; }
public virtual void SecondProcessMethod()
{
}
public abstract void ThirdSampleProcessMethod();
public string SampleProperty
{
get;
set;
}
public void Process()
{
Console.WriteLine("Process in CaseOutputGeneratorBase Called");
}
}
public class TestCaseOutputGenerator : CaseOutputGeneratorBase
{
public override void ThirdSampleProcessMethod()
{
throw new NotImplementedException();
}
}
//////////////////////////////////////////////////////////////////////////////
public class TestSandBoxManager
{
public TestSandBoxManager()
{
}
public String ProcessAssemblyByFullDisplayName(String assemblyFullDisplayName)
{
String temp = String.Empty;
var casecust = GetAssemblyByFullDisplayName(assemblyFullDisplayName);
if (casecust != null)
temp = ("Cast Passed");
else
temp = ("Cast Failed");
return temp;
}
public String ProcessFile(String assemblyName, String className)
{
String temp = String.Empty;
var casecust = GetCaseOutputGeneratorObject(assemblyName, className);
if (casecust != null)
temp=("Cast Passed");
else
temp=("Cast Failed");
return temp;
}
private static object GetAssemblyByFullDisplayName(string fullName)
{
try
{
Type caseOutputGen = null;
String fullQualifiedName = String.Empty;
var localAssembly = Assembly.LoadFrom(fullName);
foreach (var testType in localAssembly.GetTypes())
{
if ( testType.FullName != fullName)
continue;
fullQualifiedName = testType.FullName;
break;
}
if (fullQualifiedName == null)
return null;
var obj = Activator.CreateInstance(Type.GetType(fullQualifiedName));
return obj;
}
catch (Exception ex)
{
throw ex;
}
}
public String ProcessFile2(String assemblyName, String className)
{
String temp = String.Empty;
var casecust = GetCaseOutputGeneratorObjectLoadFrom(assemblyName, className);
if (casecust != null)
temp = ("Cast Passed");
else
temp = ("Cast Failed");
return temp;
}
public static ICaseOutputGenerator GetCaseOutputGeneratorObject(string assemblyName, string className)
{
ICaseOutputGenerator caseOutputGen = null;
var obj = GetObject(assemblyName, className);
if (obj != null)
caseOutputGen = (ICaseOutputGenerator)obj; // FAILS HERE
return caseOutputGen;
}
public static ICaseOutputGenerator GetCaseOutputGeneratorObjectLoadFrom(string assemblyName, string className)
{
ICaseOutputGenerator caseOutputGen = null;
try
{
var obj = GetObject2(assemblyName, className);
if (obj != null)
caseOutputGen = (ICaseOutputGenerator)obj; // FAILS HERE
}
catch (Exception ex)
{
throw ex;
}
return caseOutputGen;
}
private static object GetObject2(string fullName, string className)
{
try
{
Type caseOutputGen = null;
String fullQualifiedName = String.Empty;
var localAssembly = Assembly.LoadFrom(fullName);
foreach (var testType in localAssembly.GetTypes())
{
if (!testType.FullName.EndsWith(className, StringComparison.InvariantCultureIgnoreCase))
continue;
caseOutputGen = testType;
fullQualifiedName = testType.FullName;
break;
}
if (caseOutputGen == null)
return null;
var obj = Activator.CreateInstanceFrom(fullName, fullQualifiedName);
return obj.Unwrap();
}
catch (Exception ex)
{
throw ex;
}
}
private static object GetObject(string fullName, string className)
{
try
{
Type caseOutputGen = null;
var localAssembly = Assembly.LoadFrom(fullName);
foreach (var testType in localAssembly.GetTypes())
{
if (!testType.FullName.EndsWith(className, StringComparison.InvariantCultureIgnoreCase)) continue;
caseOutputGen = testType;
break;
}
if (caseOutputGen == null) return null;
var obj = Activator.CreateInstance(caseOutputGen);
return obj;
}
catch (FileNotFoundException ex)
{
throw new Exception("Failed to load assembly: " + Environment.NewLine + fullName, ex);
}
catch (Exception ex)
{
throw new Exception("Failed to load assembly: " + Environment.NewLine + fullName, ex);
}
}
}
//////////////////////////////////////////////////////////////////////////////
public Boolean testReflection2()
{
try
{
//create an instance of the testsandboxmanager
TestSandBoxManager t = new TestSandBoxManager();
String ret = t.ProcessFile2(#"...\Documents\visual studio 2012\Projects\TestSandBox\TestSandBox\bin\Debug\TestSandBox.dll", "TestCaseOutputGenerator");
Console.WriteLine(ret);
Console.ReadLine();
return true;
}
catch (Exception)
{
return false;
}
}
Most likely you have 2 ICaseOutputGenerator - one in each assembly. You can't cast object/interface to similarly named interface in another assembly even if code is identical. You can check the fact that create object implements ICaseOutputGenerator from its own assembly by looking at created object in the debugger.
If it is the case you need to figure out where you want to put ICaseOutputGenerator interface so it is coming from the same assembly for both "custom loaded assembly" and you main application. Often shared interfaces are implemented in separate assembly and linked to all "plug-in" assemblies as well as application assembly.
I think that Alexei Levenkov is spot on. You load your TestSandBox.dll twice. Once as a reference to your project and second time via Assembly.LoadFrom. As per documentation that you yourself linking this can result in unexpected behaviour. Here is a quote for you reference:
If an assembly is loaded with LoadFrom, and the probing path includes
an assembly with the same identity but a different location, an
InvalidCastException, MissingMethodException, or other unexpected
behavior can occur.
This is exactly what's happening in your case. If you change the path you are loading your assembly from to point to the same folder as your main executable, it will work fine.
I want to decompile a method in my assembly, which references e.g. 'Microsoft.SharePoint.dll', but I have no SharePoint installed on the machine.
If I use the following code I get an Mono.Cecil.AssemblyResolutionException 'failed to resolve assembly Microsoft.SharePoint...'.
AssemblyDefinition assembly = AssemblyDefinition.ReadAssembly("PathToMyAssembly");
ICSharpCode.Decompiler.DecompilerContext context = new ICSharpCode.Decompiler.DecompilerContext(assembly.MainModule);
AstBuilder decompiler = new AstBuilder(context);
decompiler.AddMethod(method); <!-- here it crashes -->
With the ILSpy GUI I can load my assembly without errors (on the same machine without SharePoint).
What do I need to change in my code?
I found the solution myself. I created my own AssemblyResolver which catches the AssemblyResolutionException and returns null for missing referenced assemblies.
public class MyDefaultAssemblyResolver : DefaultAssemblyResolver
{
public override AssemblyDefinition Resolve(AssemblyNameReference name)
{
try
{
return base.Resolve(name);
}
catch { }
return null;
}
public override AssemblyDefinition Resolve(AssemblyNameReference name, ReaderParameters parameters)
{
try
{
return base.Resolve(name, parameters);
}
catch { }
return null;
}
public override AssemblyDefinition Resolve(string fullName)
{
try
{
return base.Resolve(fullName);
}
catch { }
return null;
}
public override AssemblyDefinition Resolve(string fullName, ReaderParameters parameters)
{
try
{
return base.Resolve(fullName, parameters);
}
catch { }
return null;
}
}
Then I use it
var resolver = new MyDefaultAssemblyResolver();
resolver.AddSearchDirectory("FolderOfMyAssembly");
var parameters = new ReaderParameters
{
AssemblyResolver = resolver,
};
AssemblyDefinition assembly = AssemblyDefinition.ReadAssembly("PathToMyAssembly", parameters);
I found the solution by debugging the ILSpy GUI (source code is fortunately available).