Develop Reference

OleDB in Pythonnet and Mono on Mac OS X

I am trying to run several method of a dll library that I own. I use pythonnet 3.0.0dev, python3.9 and Mono 6.10.0. One of the methods triggers creating an .mdb file. On a windows machine I've install Microsoft Access Database Engine (suggested by the dll provider) and I could run my script without any problem. However, doing the same on a Mac OS X triggers the following error:
NotImplementedException: OleDb is not implemented.
at System.Data.OleDb.OleDbConnection..ctor () [0x0000b] in <bd12f551d3b343c5a146c906291931e8>:0
at (wrapper remoting-invoke-with-check) System.Data.OleDb.OleDbConnection..ctor()
at Csu.Modsim.NetworkUtils.DBUtil.OpenDBConnection () [0x0000b] in <1c83b754d09149ce95a722be79ca7efb>:0
at Csu.Modsim.NetworkUtils.DBUtil.Create (System.Boolean Overwrite, System.Boolean LeaveOpen) [0x00026] in <1c83b754d09149ce95a722be79ca7efb>:0
at Csu.Modsim.NetworkUtils.ModelOutputMSDB.InitializeOutput () [0x000a6] in <1c83b754d09149ce95a722be79ca7efb>:0
at Csu.Modsim.NetworkUtils.ModelOutputSupport.FlushOutputToCSV (Csu.Modsim.ModsimModel.Model mi, System.Boolean finalizeOutput) [0x0030d] in <1c83b754d09149ce95a722be79ca7efb>:0
at Csu.Modsim.ModsimModel.GlobalMembersOperate.operate (Csu.Modsim.ModsimModel.Model mi, Csu.Modsim.ModsimModel.Model mi2) [0x012ab] in <6f164bf9bd4744b9a0c1e4daaabc0e8a>:0
at Csu.Modsim.ModsimModel.Modsim.RunSolver (Csu.Modsim.ModsimModel.Model mi) [0x002f7] in <6f164bf9bd4744b9a0c1e4daaabc0e8a>:0
at (wrapper managed-to-native) System.Reflection.RuntimeMethodInfo.InternalInvoke(System.Reflection.RuntimeMethodInfo,object,object[],System.Exception&)
at System.Reflection.RuntimeMethodInfo.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x0006a] in <55adae4546cd485ba70e2948332ebe8c>:0
What could be a possible solution to this problem. All my installed components are 64-bit.
Thanks

Xamarin Forms Android Store crashes when i download the app, debugs perfectly on phone from VS

This is my first commit on google play store. I am using Xamarin Forms and when i run my app localy on my android phone, i have no issues.
When I Archive and Distribute the App within VS using Archive Manager and download it on my phone, or any other android phone, the App crashes before going to the 1st screen.
Under Play Console I can see the following error on the Pre-Lunch report
Blockquote
FATAL EXCEPTION: main
Process: com.*****.*****, PID: 8647
android.runtime.JavaProxyThrowable: Xamarin.Forms.Xaml.XamlParseException: Position 30:125. No method OnMenuItemSelected2 found on type *****.Menus.MainPageV2
at Xamarin.Forms.Xaml.ApplyPropertiesVisitor.SetPropertyValue (System.Object xamlelement, Xamarin.Forms.Xaml.XmlName propertyName, System.Object value, System.Object rootElement, Xamarin.Forms.Xaml.INode node, Xamarin.Forms.Xaml.HydrationContext context, System.Xml.IXmlLineInfo lineInfo) [0x000ee] in :0
at Xamarin.Forms.Xaml.ApplyPropertiesVisitor.Visit (Xamarin.Forms.Xaml.ValueNode node, Xamarin.Forms.Xaml.INode parentNode) [0x00072] in :0
at Xamarin.Forms.Xaml.ValueNode.Accept (Xamarin.Forms.Xaml.IXamlNodeVisitor visitor, Xamarin.Forms.Xaml.INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.ElementNode.Accept (Xamarin.Forms.Xaml.IXamlNodeVisitor visitor, Xamarin.Forms.Xaml.INode parentNode) [0x00043] in :0
at Xamarin.Forms.Xaml.ElementNode.Accept (Xamarin.Forms.Xaml.IXamlNodeVisitor visitor, Xamarin.Forms.Xaml.INode parentNode) [0x00078] in :0
at Xamarin.Forms.Xaml.ElementNode.Accept (Xamarin.Forms.Xaml.IXamlNodeVisitor visitor, Xamarin.Forms.Xaml.INode parentNode) [0x00078] in :0
at Xamarin.Forms.Xaml.RootNode.Accept (Xamarin.Forms.Xaml.IXamlNodeVisitor visitor, Xamarin.Forms.Xaml.INode parentNode) [0x00043] in :0
at Xamarin.Forms.Xaml.XamlLoader.Visit (Xamarin.Forms.Xaml.RootNode rootnode, Xamarin.Forms.Xaml.HydrationContext visitorContext) [0x00083] in :0
at Xamarin.Forms.Xaml.XamlLoader.Load (System.Object view, System.String xaml) [0x0008f] in :0
at Xamarin.Forms.Xaml.XamlLoader.Load (System.Object view, System.Type callingType) [0x0002f] in :0
at Xamarin.Forms.Xaml.Extensions.LoadFromXaml[TXaml] (TXaml view, System.Type callingType) [0x00000] in :0
at ****.Menus.MainPageV2.InitializeComponent () [0x00000] in :0
at ****.Menus.MainPageV2..ctor () [0x00006] in :0
at ****.App..ctor () [0x0000c] in :0
at ****.Droid.MainActivity.OnCreate (Android.OS.Bundle bundle) [0x00022] in :0
at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_savedInstanceState) [0x0000f] in :0
at (wrapper dynamic-method) System.Object:efb18139-d766-47ea-a9bd-57beaf3952f0 (intptr,intptr,intptr)
at md5684c7b5241d0a7c4d4ea0533a804cbec.MainActivity.n_onCreate(Native Method)
at md5684c7b5241d0a7c4d4ea0533a804cbec.MainActivity.onCreate(MainActivity.java:29)
at android.app.Activity.performCreate(Activity.java:6975)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
The thing is that my Menus.MainPageV2 includes OnMenuItemSelected2 which is run just fine when testing localy
The automated Google Test results on the on the Pre-Lunch report are failing for all testing devices with the same error.
Things I tried changing, re-Archiving and Distributing:
- Closed VS, cleaned bin, obj directories and Re-Built
- Upgraded to the latest Xamarin Forms Nuget
- Linking with None, Sdk and User Assemblies, Sdk Assemblies only
Anyone have any ideas on what else i might try to get this to work ?
Thank you for your time.

App crashes in release mode and not in debug mode - Xamarin Forms

I am building a cross platform app and i want to release it to testers, but it doesn't work when i am deploying it in release mode. As far as exceptions go i do not get any. As stated in the question it works in debug mode. The app just goes to splashscreen and crashes. I ran the original app through test fairy and got this exception:
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
... 2 more
Caused by: md52ce486a14f4bcd95899665e9d932190b.JavaProxyThrowable: System.IO.FileNotFoundException: Could not load file or assembly '<Censored: Name of forms class library>.dll' or one of its dependencies. The system cannot find the file specified.
File name: '<Censored: Name of forms class library>.dll'
at System.AppDomain.Load (System.Reflection.AssemblyName assemblyRef, System.Security.Policy.Evidence assemblySecurity) [0x00000] in :0
at System.AppDomain.Load (System.Reflection.AssemblyName assemblyRef) [0x00000] in :0
at (wrapper remoting-invoke-with-check) System.AppDomain:Load (System.Reflection.AssemblyName)
at System.Reflection.Assembly.Load (System.Reflection.AssemblyName assemblyRef) [0x00000] in :0
at Xamarin.Forms.Xaml.XamlParser.GetElementType (Xamarin.Forms.Xaml.XmlType xmlType, IXmlLineInfo xmlInfo, System.Reflection.Assembly currentAssembly, Xamarin.Forms.Xaml.XamlParseException& exception) [0x00000] in :0
at (wrapper delegate-invoke) :invoke_Type_XmlType_IXmlLineInfo_Assembly_XamlParseException& (Xamarin.Forms.Xaml.XmlType,System.Xml.IXmlLineInfo,System.Reflection.Assembly,Xamarin.Forms.Xaml.XamlParseException&)
at Xamarin.Forms.Xaml.XamlTypeResolver.Resolve (System.String qualifiedTypeName, IServiceProvider serviceProvider, Xamarin.Forms.Xaml.XamlParseException& exception) [0x00000] in :0
at Xamarin.Forms.Xaml.XamlTypeResolver.TryResolve (System.String qualifiedTypeName, System.Type& type) [0x00000] in :0
at Xamarin.Forms.Xaml.ExpandMarkupsVisitor+MarkupExpansionParser.Parse (System.String match, System.String& remaining, IServiceProvider serviceProvider) [0x00000] in :0
at Xamarin.Forms.Xaml.ExpandMarkupsVisitor.ParseExpression (System.String& expression, IXmlNamespaceResolver nsResolver, IXmlLineInfo xmlLineInfo, INode node, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.ExpandMarkupsVisitor.Visit (Xamarin.Forms.Xaml.MarkupNode markupnode, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.MarkupNode.Accept (IXamlNodeVisitor visitor, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.ElementNode.Accept (IXamlNodeVisitor visitor, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.ElementNode.Accept (IXamlNodeVisitor visitor, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.RootNode.Accept (IXamlNodeVisitor visitor, INode parentNode) [0x00000] in :0
at Xamarin.Forms.Xaml.XamlLoader.Load (Xamarin.Forms.BindableObject view, System.String xaml) [0x00000] in :0
at Xamarin.Forms.Xaml.XamlLoader.Load (Xamarin.Forms.BindableObject view, System.Type callingType) [0x00000] in :0
at Xamarin.Forms.Xaml.Extensions.LoadFromXaml[LoginPage] (<Censored>.Login.LoginPage view, System.Type callingType) [0x00000] in :0
at <Censored>.Login.LoginPage.InitializeComponent () [0x00000] in :0
at <Censored>.Login.LoginPage..ctor () [0x00000] in :0
at <Censored>.App.b__0 () [0x00000] in :0
at <Censored>.ViewFactory.Resolve[LoginViewModel] (<Censored>.Login.LoginViewModel viewModel) [0x00000] in :0
at <Censored>.App..ctor () [0x00000] in :0
at md5b406f03a919343acc4f3b337a44e1248.MainActivity.n_onCreate(Native Method)
at md5b406f03a919343acc4f3b337a44e1248.MainActivity.onCreate(MainActivity.java:28)
at android.app.Activity.performCreate(Activity.java:5458)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2376)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2470)
at android.app.ActivityThread.access$900(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1307)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5593)
... 5 more
I cannot show you the source code, but i have reproduced the error in a new test solution.
Here is a link to the repository with the test project. It is just a project using MVVM with Xamarin Forms.

Fixed it by manually deleting all obj folders and all bin folders in the entire solution.
Edit: Came back again and now this fix does not work!

If your solution works in Debug mode, but not in Release mode, it might be an issue with the Linker.
Right Click on your specific project (not Solution) -> Android Options -> Linker -> Choose "None" in Linking. This will include all dlls in the Release Library.

Method not found: 'System.Web.Hosting.HostingEnvironment.get_InClientBuildManager'

I'm running ASP.NET MVC 4 application on Linux machine thanks to Mono, my problem is that each time I run it for few seconds instead of displaying page I get following error:
System.MissingMethodException
Method not found: 'System.Web.Hosting.HostingEnvironment.get_InClientBuildManager'.
Description:
HTTP 500.Error processing request.
Details:
Non-web exception. Exception origin (name of application or object): mscorlib.
Exception stack trace:
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
Version Information(server is xsp):
3.2.8 (Debian 3.2.8+dfsg-4ubuntu1); ASP.NET Version: 4.0.30319.17020
Detailed info:
[System.Web.HttpException]: The pre-application start initialization method Run on type WebActivatorEx.ActivationManager threw an exception with the following error message: Exception has been thrown by the target of an invocation. at System.Web.Compilation.BuildManager.CallPreStartMethods () [0x00000] in :0 at System.Web.HttpApplicationFactory.InitType (System.Web.HttpContext context) [0x00000] in :0 [System.Reflection.TargetInvocationException]: Exception has been thrown by the target of an invocation. at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in :0 at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in :0 at System.Web.Compilation.BuildManager.CallPreStartMethods () [0x00000] in :0 [System.MissingMethodException]: Method not found: 'System.Web.Hosting.HostingEnvironment.get_InClientBuildManager'. at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&) at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in :0
As I said, this error is gone shortly after starting application but I'm looking for solution to it. I don't have similiar error on other machine.
Version information(Debian+Nginx+FastCGI):
3.6.1 (master/1910095 Mon Jul 7 12:30:38 CEST 2014); ASP.NET Version: 4.0.30319.17020

C# MonoDevelop: Invalid -langversion CS1617

I just installed MonoDevelop 5.0.1 in Ubuntu 12.04 and tried to compile a simple Hello World.
This results in the following build error:
Error CS1617: Invalid -langversion option `Version5'. It must be `ISO-1', `ISO-2', `3', `4', `5', `Default' or `Future' (CS1617)
I looked through the options and everything I found seems to be set up correctly. Edit>Preferences>Projects>.NET Runtimes has Mono 3.2.1 included.
The only section I cannot access is Project>Project Options>Build>General, which causes an Exception to be thrown:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.Exception: Unknown LangVersion string ''
at MonoDevelop.CSharp.Project.CSharpCompilerParameters.get_LangVersion () [0x00000] in <filename unknown>:0
at MonoDevelop.CSharp.Project.CompilerOptionsPanelWidget..ctor (MonoDevelop.Projects.DotNetProject project) [0x00000] in <filename unknown>:0
at MonoDevelop.CSharp.Project.CompilerOptionsPanel.CreatePanelWidget () [0x00000] in <filename unknown>:0
at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.CreatePageWidget (MonoDevelop.Ide.Gui.Dialogs.SectionPage page) [0x00000] in <filename unknown>:0
at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.ShowPage (MonoDevelop.Ide.Extensions.OptionsDialogSection section) [0x00000] in <filename unknown>:0
at MonoDevelop.Ide.Gui.Dialogs.OptionsDialog.OnSelectionChanged (System.Object s, System.EventArgs a) [0x00000] in <filename unknown>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0
at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0
The same error already occurred in MonoDevelop 2.something from the Ubuntu package manager.

I can't help you with the solution may be, but I can give you why this is happening -
Please visit this links -
The reason http://msdn.microsoft.com/en-us/library/ydy7a2we(v=vs.90).aspx
Mono Develop System Requirements.
http://monodevelop.com/developers/building_monodevelop
Make sure that MonoDeveloper supports the Mono version you are using.

I (think I) found the issue and now it appears to be working correctly. Apparently, one of the project files was corrupted for some reason. Deleting the old project and creating a new one helped.