Instantiating a .NET class with a reference to a dll causes FileNotFoundException - c#

I've added as reference PDFSharp classes for a project. When I tried to use a method in a class that includes PDFSharp libraries I get a FileNotFoundException that states I'm missing the referenced (PDFSharp) file (while I can assure you the dll file is there).
So I've tried adding and readding and changing the dll version, but still without success. So I switched to PDFClown, a similar purpose library, but the error is the same: FileNotFoundException at runtime.
The exception is thrown even before the method is executed.
Calling method (where the exception is thrown):
//method call: here the debugger stops at the breakpoint
ReportUtils.CreateFile(tempDirectoryPath ecc);
Called method:
using org.pdfclown.documents;
using org.pdfclown.documents.contents.composition;
using org.pdfclown.documents.contents.fonts;
using clownFiles = org.pdfclown.files;
class ReportUtils
{
public static void CreateFile(/*parameters*/)
{
//the debugger never enter here: the exception is thrown before
string filename = Settings.ReportFileName + String.Format("{0:yyyyMMddHHmmssffff}", DateTime.Now);
//ecc
}
//...
Why is this exception showing up? Am I doing something wrong adding the references?

I could reproduce your issue by setting the option Copy Local on my library to false. Please, make sure this boolean is set to true..

Related

Unknown exception at declaration and initalisation of a Class

The main Problem is completely different, please skip to the Edit
I have an exception of an unknown type which doesn't even get thrown properly. Following Code provides the Context:
MMDataAccess.InitDemoDB();
MMDataAccess.InitInternalDB();
MMDataAccess.InitMaintDB();
try
{
SQLiteToDBLib sqltdbl = new SQLiteToDBLib();
sqltdbl.WriteToSQLite();
}
catch(Exception ex)
{
string message = ex.Message;
}
These are the very first lines of my first Activity in my app. The first 3 lines belong to my very own implementation of an in-memory database and are behaving nicely. The problem rises with the next two lines inside the try-block. The declaration and initalistation of the sqltdbl variable never happens. The constructor of SQLiteToDBLib looks like this:
public SQLiteToDBLib()
{
msc = new MSConnection();
}
The MSConnection class doesn't even have a constructor (except for the default one of course).
As you can see i've tried to catch any exceptions, but without success. everything i can figure out is, that a exception is thrown because of the debugger going into the catch section while ignoring everything that has to do with "ex". Without breakpoints everything seems fine. Just without the call to WriteToSQLite which should create a .sqlite file on the external Memory.
What can I do to resolve this error? Is there anything i can catch except the default Exception?
Edit:
After some testing with commented code something interresting happened. I could step into commented code. Well not exactly the commented code, but the code that was there before my changes. Visual Studio somehow shows me the things, that are changed in the file, but is compiling the old code. Up to now i tried to rebuild, clean and build the project in various combinations, unload and reload the project, Restart Visual Studio and restart Windows. Nothing has changed so far. I Will now proceed to create a new .cs File With the exact same Code. I'm working with VS 2013 Community
add static constructor to your SQLiteToDBLib class and perform all static objects initialization in it:
static SQLiteToDBLib()
{
// initialize static members here
}
If this doesn't give you a clue, try enabling CLRE exceptions-break in visual-studio:
DEBUG
Exceptions
Check the 'Common Language Runtime Exceptions' option (under the 'Thrown' column)
Press OK
Restart your app and try again

Executable fails with weird exception

I am using ILMerge and Quartz.NET in a C# .NET 4.0 Windows Service application. The app runs fine without using ILMerge, but now that we're nearing shipping release, I wanted to combine all DLLs into a single executable.
Problem is, that ILMerge seems to work fine, but when I run the combined executable, it throws this exception:
Unhandled Exception: Quartz.SchedulerException: ThreadPool type 'Quartz.Simpl.SimpleThreadPool' could not be instantiated. ---> System.InvalidCastException: Unable to cast object of type 'Quartz.Simpl.SimpleThreadPool' to type 'Quartz.Spi.IThreadPool'.
at Quartz.Util.ObjectUtils.InstantiateType[T](Type type) in :line 0
at Quartz.Impl.StdSchedulerFactory.Instantiate() in :line 0
--- End of inner exception stack trace ---
at Quartz.Impl.StdSchedulerFactory.Instantiate() in :line 0
at Quartz.Impl.StdSchedulerFactory.GetScheduler() in :line 0
Does anyone have any idea why this is? I have been wasting over 4 hours already and I can't figure it out. If I don't combine with ILMerge, then everything runs fine (with the Quartz.dll and Common.Logging.dll in the same directory).
I'm sure someone must have tried packaging Quartz.net up like this before, any ideas?
Disclaimer: I don't know Quartz.NET at all, although I spent some time struggling with ILMerge. When I finally understood its limitations... I stopped using it.
ILMerge'd application tends to have problems with everything which contains the word "reflection".
I can guess (I've never used Quartz.NET) that some classes are resolved using reflection and driven by configuration files.
Class is not only identified by its name (with namespace) but also by assembly it is coming from (unfortunatelly it doesn't get displayed in exception message).
So, let's assume you had (before ILMerging) two assemblies A (for you Application) and Q (for Quartz.NET).
Assembly 'A' was referencing assembly 'Q' and was using a class 'Q:QClass' which was implementing 'Q:QIntf'.
After merging, those classes became 'A:QClass' and 'A:QIntf' (they were moved from assembly Q to A) and all the references in code has been replaced to use those (completely) new classes/interfaces, so "A:QClass" is implementing "A:QIntf" now.
But, it did not change any config files/embedded strings which may still reference "Q:QClass".
So when application is reading those not-updated config files it still loads "Q:QClass" (why it CAN find it is a different question, maybe you left assembly 'Q' in current folder or maybe it is in GAC - see 1).
Anyway, "Q:QClass" DOES NOT implement "A:QIntf", it still implements "Q:QIntf" even if they are binary identical - so you can't cast 'Q:QClass' to 'A:QIntf'.
The not-ideal-but-working solution is to "embed" assemblies instead of "merging" them. I wrote a open-source tool which does it (embedding instead of merging) but it is not related to this question. So if you decide to embed just ask me.
You can test it by removing (hiding, whatever works for you) every single instance of Q.dll on your PC. If I'm right, the exception should say now 'FileNotFound'.
You could try creating your own ISchedulerFactory and avoid using reflection to load all of your types.
The StdSchedulerFactory uses this code to creat a threadpool. It's where your error is happening and would be the place to start looking at making changes:
Type tpType = loadHelper.LoadType(cfg.GetStringProperty(PropertyThreadPoolType)) ?? typeof(SimpleThreadPool);
try
{
tp = ObjectUtils.InstantiateType<IThreadPool>(tpType);
}
catch (Exception e)
{
initException = new SchedulerException("ThreadPool type '{0}' could not be instantiated.".FormatInvariant(tpType), e);
throw initException;
}
The ObjectUtils.InstantiateType method that is called is this one, and the last line is the one throwing your exception:
public static T InstantiateType<T>(Type type)
{
if (type == null)
{
throw new ArgumentNullException("type", "Cannot instantiate null");
}
ConstructorInfo ci = type.GetConstructor(Type.EmptyTypes);
if (ci == null)
{
throw new ArgumentException("Cannot instantiate type which has no empty constructor", type.Name);
}
return (T) ci.Invoke(new object[0]);
}
Right after this section in the factory, datasources are loaded using the same pattern and then the jobs themselves are also loaded dynamically which means you'd also have to write your own JobFactory. Since Quartz.Net loads a bunch of bits and pieces dynamically at runtime going down this road means you might end up rewriting a fair amount of things.

Assembly Location Changes in Runtime

I'm running coded ui automation and defined a method attribute called [ExternalDataSource()] to read a document (csv, xml...) and parse the data into some dictionaries. I'll copy it here so you can have a better insight:
[System.AttributeUsage(System.AttributeTargets.Method)]
public class ExternalDataSource : System.Attribute
{
public ExternalDataSource(string filename)
{
DirectoryInfo di = new DirectoryInfo(Assembly.GetExecutingAssembly().Location);
string file = Path.Combine(Path.GetDirectoryName(di.FullName), filename);
try
{
code
}
catch (Exception)
{
throw new UITestException("Cannot load data source document");
}
}
}
In it I try to access Assembly.GetExecutingAssembly().Location to get a file that is copied to the TestResult/Out folder. I assigned this attribute to only one TestMethod() in the whole application and while debugging, I found out that the application enters the attribute's c'tor twice. Both times the Location is different. Once it's from the bin/Debug folder, the other time it's from the TestResults/Out folder. Two questions:
Why does the debugger enter that attribute twice if I call it only once in my application?
Why does the location of the same assembly change?
Well it seems nobody had an answer, but while debugging a run from the command line using mstest.exe with the vs2012 JIT Debugger i found out a strange thing:
When putting a System.Diagnostics.Debugger.Break() in the class where this attribute is the jitter was called from MSTest.exe but when this breakpoint was in the testmethod decorated with this attribute, QTAgent32.exe was called. I had implemented a singleton class to handle my parameters, and while it was populated in ExternalDataSource in this attribute by MSTest, when entering QTAgent32 (the test) it was empty.
The solution that worked for me was just to initialize that Singleton with the data on [TestInitialize()].
Hope this helps somebody.

Is it possible to use Gephi compiled with IKVM in a website?

I'm currently trying to load and use the Gephi Toolkit from within a .Net 4 C# website.
I have a version of the toolkit jar file compiled against the IKVM virtual machine, which works as expected from a command line application using the following code:
var controller = (ProjectController)Lookup.getDefault().lookup(typeof(ProjectController));
controller.closeCurrentProject();
controller.newProject();
var project = controller.getCurrentProject();
var workspace = controller.getCurrentWorkspace();
The three instances are correctly instantiated in a form similar to org.gephi.project.impl.ProjectControllerImpl#8ddb93.
If however I run the exact same code, with the exact same using statements & references, the very first line loading the ProjectController instance returns null.
I have tried a couple of solutions
Firstly, I have tried ignoring the Lookup.getDefault().lookup(type) call, instead trying to create my own instances:
var controller = new ProjectControllerImpl();
controller.closeCurrentProject();
controller.newProject();
var project = controller.getCurrentProject();
var workspace = controller.getCurrentWorkspace();
This fails at the line controller.newProject();, I think because internally (using reflector) the same Lookup.getDefault().lookup(type) is used in a constructor, returns null and then throws an exception.
Secondly, from here: Lookup in Jython (and Gephi) I have tried to set the %CLASSPATH% to the location of both the toolkit JAR and DLL files.
Is there a reason why the Lookup.getDefault().lookup(type) would not work in a web environment? I'm not a Java developer, so I am a bit out of my depth with the Java side of this.
I would have thought it possible to create all of the instances myself, but haven't been able to find a way to do so.
I also cannot find a way of seeing why the ProjectController load returned null. No exception is thrown, and unless I'm being very dumb, there doesn't appear to be a method to see the result of the attempted load.
Update - Answer
Based on the answer from Jeroen Frijters, I resolved the issue like this:
public class Global : System.Web.HttpApplication
{
public Global()
{
var assembly = Assembly.LoadFrom(Path.Combine(root, "gephi-toolkit.dll"));
var acl = new AssemblyClassLoader(assembly);
java.lang.Thread.currentThread().setContextClassLoader(new MySystemClassLoader(acl));
}
}
internal class MySystemClassLoader : ClassLoader
{
public MySystemClassLoader(ClassLoader parent)
: base(new AppDomainAssemblyClassLoader(typeof(MySystemClassLoader).Assembly))
{ }
}
The code ikvm.runtime.Startup.addBootClassPathAssemby() didn't seem to work for me, but from the provided link, I was able to find a solution that seems to work in all instances.
This is a Java class loader issue. In a command line app your main executable functions as the system class loader and knows how to load assembly dependencies, but in a web process there is no main executable so that system class loader doesn't know how to load anything useful.
One of the solutions is to call ikvm.runtime.Startup.addBootClassPathAssemby() to add the relevant assemblies to the boot class loader.
For more on IKVM class loading issues see http://sourceforge.net/apps/mediawiki/ikvm/index.php?title=ClassLoader

The type initializer for 'MyClass' threw an exception

The following is my Windows service code. When I am debugging the code, I am getting the error/ exception:
The type initializer for 'CSMessageUtility.CSDetails' threw an exception.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.IO;
using System.Threading;
using System.Windows;
using System.Windows.Forms;
using CSMessageUtility;
namespace CS_Data_Trasmmiting_Service
{
public partial class svcCSWinServ : ServiceBase
{
//private string sLogFormat;
//private string sErrorTime;
private Thread new_thread;
Logger logObject = new Logger();
private bool isenable = true;
public svcCSWinServ()
{
InitializeComponent();
logObject.append("Initialize Service " + DateTime.Now.ToString(), 70);
CheckForAlarms();
}
protected override void OnStart(string[] args)
{
try
{
new_thread = new Thread(new ThreadStart(CheckForAlarms));
new_thread.Start();
}
catch
{
}
logObject.append("Service Started successfully " + DateTime.Now.ToString(), 70);
}
protected override void OnStop()
{
try
{
isenable = false;
new_thread.Abort();
}
catch
{
}
logObject.append("Service Stopped successfully " + DateTime.Now.ToString(), 70);
}
void CheckForAlarms()
{
try
{
while (true)
{
//if((DateTime.Now.ToString("HH:mm") == "18:00"))
//{
logObject.append("Start Sending Data " +DateTime.Now.ToString(), 70);
try
{
//SendAllInfo();
string str = CSMessageUtility.CSDetails.createDHSMessageFormat();
Thread.Sleep(2000);
string str1 = CSMessageUtility.CSDetails.createEALMessageFormat();
Thread.Sleep(2000);
string str2 = CSMessageUtility.CSDetails.createProductStatusMessageForamt();
Thread.Sleep(2000);
string str3 = CSMessageUtility.CSDetails.createEODMessageFormat();
Thread.Sleep(2000);
string str4 = CSDetails.createProductReceiptEntryatBOSMessageFormat();
Thread.Sleep(2000);
string str5 = CSMessageUtility.CSDetails.createProductSaleMessageFormat();
Thread.Sleep(2000);
string str6 = CSMessageUtility.CSDetails.createTotalizerExceptionMessageFormat();
Thread.Sleep(2000);
//CSMessageUtility.CSDetails.createDailyCOtransferMessageFormat();
//Thread.Sleep(2000);
}
catch (Exception ee)
{
logObject.append(ee.Message, 70);
}
logObject.append("Finished Sending Data " +DateTime.Now.ToString(), 70);
Thread.Sleep(3000);
//}
//Thread.Sleep(20000);
}
}
catch (Exception ex)
{
logObject.append("Thread Exception: "+ ex.Message + " "+ DateTime.Now.ToString(), 70);
try
{
new_thread.Abort();
}
catch (Exception ex1)
{
logObject.append("Thread Exception: " +ex1.Message + " " + DateTime.Now.ToString(), 70);
}
if (isenable == true)
{
new_thread = new Thread(new ThreadStart(CheckForAlarms));
new_thread.Start();
}
}
}
}
}
Check the InnerException property of the TypeInitializationException; it is likely to contain information about the underlying problem, and exactly where it occurred.
This problem can be caused if a class tries to get value of a key in web.config or app.config which is not present there.
e.g.
The class has a static variable
private static string ClientID = System.Configuration.ConfigurationSettings.AppSettings["GoogleCalendarApplicationClientID"].ToString();
But the web.config doesn't contain the GoogleCalendarApplicationClientID key
The error will be thrown on any static function call or any class instance creation
The type initializer for 'CSMessageUtility.CSDetails' threw an exception. means that the static constructor on that class threw an Exception - so you need to look either in the static constructor of the CSDetails class, or in the initialisation of any static members of that class.
I ran into the same problem, when I was using a static methods in a Util class, just like you had used CSMessageUtility.CSDetails.
The problem was that during the static initialization of the class (using the static constructor), the framework also initialize the the static variables (fields) in the class. I had a static variable that attempts to read values from app.config, and app.config was missing the respective settings, thus resulting in an un-handled exception. This resulted in getting the
"Object reference not set to an instance of an object."
as the inner exception.
One other thing to check when these initialize errors are thrown would be to check if the target .NET version is installed on the server. You can right click the project and see what .NET version the application is targeting.
Dictionary keys should be unique !
In my case, I was using a Dictionary, and I found two items in it have accidentally the same key.
Dictionary<string, string> myDictionary = new Dictionary<string, string>() {
{"KEY1", "V1"},
{"KEY1", "V2" },
{"KEY3", "V3"},
};
This can happen if you have a dependency property that is registered to the wrong owner type (ownerType argument).
Notice SomeOtherControl should have been YourControl.
public partial class YourControl
{
public bool Enabled
{
get { return (bool)GetValue(EnabledProperty); }
set { SetValue(EnabledProperty, value); }
}
public static readonly DependencyProperty EnabledProperty =
DependencyProperty.Register(nameof(Enabled), typeof(bool), typeof(SomeOtherControl), new PropertyMetadata(false));
}
I've had the same problem caused by having two of the same configuration properties (which matches the app.config):
[ConfigurationProperty("TransferTimeValidity")]
Another scenario that might cause this is when you have a piece of your code that calls:
string sParam = **ConfigurationManager.AppSettings["SOME_PARAM"].ToString();
Keep in mind that you have to use the OWSTIMER.EXE.CONFIG file for configuration file settings. I had an App.config file that I was trying to read and I was getting this error because on instantiation of my job instance, I had a line in my code that was referring to Connfiguration.AppSettings & Configuration.ConnectionStrings. Just make sure that you go the path:
C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN
and place your configuration settings in the OWSTIMER.EXE.CONFIG file.
If for whatever reason the power goes or the Visual Studio IDE crashes it can cause this problem inside your bin/debug bin/release...
Just delete the content and recompile (from personal experience when my toe hit the reset button!)
I had a different but still related configuration.
Could be a custom configuration section that hasn't been declared in configSections.
Just declare the section and the error should resolve itself.
I encountered this issue due to mismatch between the runtime versions of the assemblies. Please verify the runtime versions of the main assembly (calling application) and the referred assembly
As the Error says the initialization of the Type/Class failed. This usually occurs when there is some exception in the constructor of the class. Most common reason is you assign some value in the constructor reading from a config file and the config file is missing those values.
Noteworthy: I had multiple projects in my solution and I forgot to add the references/Nuget libraries. When I ran a method in the static class, which used the given libraries, it threw the exception mentioned.
In my case I had this failing on Logger.Create inside a class library that was being used by my main (console) app. The problem was I had forgotten to add a reference to NLog.dll in my console app. Adding the reference with the correct .NET Framework library version fixed the problem.
Had a case like this in a WPF project. My issue was on a line that went like this:
DataTable myTable = FillTable(strMySqlQuery);
Where FillTable() returned a DataTable based on a SQL query string. If I did the "copy exception to clipboard" option, I think it was, and pasted into Notepad, I could see the message. For me, it was The input is not a valid Base-64 string as it contains a non-base 64 character.
My actual problem wasn't that the query string had something that shouldn't be there, like I was thinking, because string strMySqlQuery = "SELECT * FROM My_Table" was my string and thought it could be the * or _, but the actual problem was in FillTable(), where I had a call to another function, GetConnection() that returned an OracleConnection object, in order to open it and retrieve and return the DataTable. Inside GetConnection() I was getting the app.config parameters for my connection string, and I had one of them misnamed, so it was setting a null value for the service account's password and not making the DB connection. So it's not always where the error is exactly correct for all circumstances. Best to dive into the function where the error is and debug step-by-step and ensure all values are getting filled with what you expect.
I too faced this error in two situation
While performing redirection from BAL layer to DAL layer I faced this exception. Inner exception says that "Object Reference error".
Web.Config file key does not match.
Hope this useful to solve your problem.
Similar to what Muhammad Iqbal stated.. I was in a VB.NET (may also be C#) project where I did remove a key-value pair from the App.config which was referenced by a variable global to the Sub Main() of Module Main. Therefore, the exception (and break) occurs in Module Main before the Sub Main(). If only I had a break-point on the Dim, but we don't usually break on global variables. Perhaps a good reason not to declare globals referencing App.config? In other words, this...
An unhandled exception of type 'System.TypeInitializationException' occurred in Unknown Module.
The type initializer for 'Namespace.Main' threw an exception.
Is caused by...
App.config
<connectionStrings>
<!--<add name="ConnectionString1" connectionString="..." />-->
Main module
Module Main
Dim cnnString As String = ConfigurationManager.ConnectionStrings("ConnectionString1") '<-- BREAK HERE (EXCEPTION)
Sub Main()
// main code
End Main
End Module
In my case, I had a helper class that was static. In that class was a method to initialize a SqlCommand dependent on variables. As this was being called in several places I moved it to the helper class and called as needed, so this method was also static. Now I had a global property that was the connection string in Global.asax pointing to the connection string in web.config. Intermittently I would get "The type initializer for 'Helper' threw an exception". If I moved the method from the Helper class to the class where it was being called from all was good. The inner exception complained of the object being null (Helper class). What I did was add Using Helper to Global.asax and even though it was not being used by Global.asax this solved the problem.
My Answer is also related to Config section. If you assign values from Config file at static class of C# or Module.VB of VB, you will get this error at run time.
add key="LogPath" value="~/Error_Log/"
Using Forward slash in Web.Config also leads to this error on Run time. I just resolved this issue by putting BackSlash
add key="LogPath" value="~\Error_Log\"
I wrapped my line that was crashing in a try-catch block, printed out the exception, and breaked immediately after it was printed. The exception information shown had a stack trace which pointed me to the file and line of code causing the fault to occur.
System.TypeInitializationException: The type initializer for 'Blah.blah.blah' threw an exception.
---> System.NullReferenceException: Object reference not set to an instance of an object.
at Some.Faulty.Software..cctor() in C:\Projects\My.Faulty.File.cs:line 56
--- End of inner exception stack trace ---
at Blah.blah.blah(Blah.blah.blah)
at TestApplication.Program.Main(String[] args)
in C:\Projects\Blah.blah.blah\Program.cs:line 29 Exception caught.
Somehow exiting Visual Studio and re-opening it solved this for me.

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