Mono is a really cool concept. It’s a C# compiler/framework that works cross-platform. C# is fantastic, so I really like the idea of being able to develop C# (potentially with Visual Studio) and target any device. Until Mono came along, C# was only used on Windows because it uses the Microsoft .NET framework. (Mono also boasts the MonoGame platform and the MonoDevelop IDE for Linux coding.)

Here is the introduction from the Mono Wikipedia page:

“Mono is a free and open source project led by Xamarin (formerly by Novell and originally by Ximian) to create an Ecma standard compliant .NET Framework-compatible set of tools including, among others, a C# compiler and a Common Language Runtime.

The stated purpose of Mono is not only to be able to run Microsoft .NET applications cross-platform, but also to bring better development tools to Linux developers.^[3] Mono can be run on many software systems including Android (and most other Linux distributions), BSD, iOS, OS X,Windows, Solaris, and some for game consoles such as PlayStation 3, Wii, and Xbox 360.”

So I downloaded Mono to try it out on Windows (I’ll try Ubuntu next) and I ran into an issue right away. Just trying to validate the install using the “Hello World” example on the Mono Basics page didn’t work. It’s really not that complicated, here’s the example program:

using System;
 
public class HelloWorld
{
    static public void Main ()
    {
        Console.WriteLine ("Hello Mono World");
    }
 
}

However, I couldn’t get it to work using the gmcs compiler that’s used in the example. The result was this all too common error:

C:\Mono\Mono-3.0.5>gmcs
'gmcs' is not recognized as an internal or external command, operable program or batch file.

This error will occur on Windows when the program actually doesn’t exist, or it can’t be discovered from the location that the console is running. There are two way to fix this issue for any Windows program:

1. Use the full path to the program and use quotes if the path has spaces in it

2. Add the path for the program to the Windows Environment Variable called “Path.”

So I tried to find the executable for gmcs, but I could not even find gmcs.bat or gmcs.exe. In this case, it wasn’t an issue with Windows or Mono, it was simply out of date documentation on the Mono site.

I received this helpful advice from the Mono user community forum, “Have you tried "mcs -sdk:2"? Mono 2.11 merged all the compilers into the one unified compiler, and now gmcs is a shell script that simply calls mcs (at least on Linux).” Ah, that’s good to know!

Here is the working version of the “basics” test code:

C:\Windows\System32>mcs --about
The Mono C# compiler is Copyright 2001-2011, Novell, Inc.
The compiler source code is released under the terms of the
MIT X11 or GNU GPL licenses
For more information on Mono, visit the project Web site
   http://www.mono-project.com
The compiler was written by Miguel de Icaza, Ravi Pratap, Martin Baulig, Marek Safar, Raja R Harinath, Atushi Enomoto

C:\Windows\System32>cd C:\Mono\Mono-3.0.5

C:\Mono\Mono-3.0.5>mcs helloworld.cs

C:\Mono\Mono-3.0.5>mono helloworld.exe
Hello Mono World

Success!

I ran into a strange issue and so many different solutions have been posted online that I thought I’d add what worked for my scenario. I have an ASP.NET MVC 3 “Razor” web application which I ran successfully on W2K8 R2 and when I tried to open it on Windows 7  (IIS 7.5), it wouldn’t run. The error message was “HTTP Error 403.14 – Forbidden. A default document is not configured for the requested URL.” I know that I don’t need to set a default document, so what is wrong?

There are an awful lot of posts about this error, but the key here is that this solution worked fine on one machine and wouldn’t run on another. I found the solution that worked for me on StackOverflow.com. It was the suggestion from Dommer that helped with my issue. (Note that there is a 32bit version of the same fix.)

“did you try running the aspnet_regiis -i command in the Visual Studio 64 bit command prompt (with admin privileges)? When I did that it fixed it for the 64-bit mode. To clarify, I right clicked on Visual Studio x64 Win64 Command Prompt (2010) and chose Run as Administrator. Then I went here: C:\Windows\Microsoft.NET\Framework64\v4.0.30319
And did this: aspnet_regiis –i And now it works perfectly.”

Yes, yes it does. Thanks!

While working with some XML documents, I ran into this cryptic error: “There is an error in XML document (2, 2).” The problem turned out to be a surprising case sensitivity in the C# code. When I was trying to deserialize from XML to an object, the XML elements didn’t match the case of the class properties.

Here is my original XML file:

  stephen

Test class:

public class Test
{
  public string Name { get; set; }
}

And the code that I was using to deserialize the XML into the Test class object.

string xmlFile = String.Concat(HttpContext.Current.Request.PhysicalApplicationPath, "test.xml"); System.IO.StreamReader reader = System.IO.File.OpenText(xmlFile);
XmlSerializer xs = new XmlSerializer(typeof(ReportTemplate));
Test testData = (ReportTemplate)xs.Deserialize(reader);

The solution was quite simple. The case of the XML tags did not match the case of the class properties. By changing them to match, I resolved the error. Here is the working XML:

   stephen

BTW – If the root element case matches, but one of the sub-elements does not, you will see the beloved error “Object reference not set to an instance of an object.”

I’ve been working to clean up my SharePoint Game of Life web part so that I can give it out publicly. I found recently that when I added an ASP.NET  Table control to an ASCX page, I could no longer select the individual controls on the page. This is annoying since I you can’t quickly get to their property grids.

In the Visual Studio designer view, I could only select the Table control that now encompassed all of the other controls.  If I clicked on anything, it just selected the large table. The other ways of selecting nested controls that I would use with WinForms don't work either.

                         - after adding the table, only the whole table could be selected

After messing about, I found the solution. Since I don't actually need the main table to be a Table control, all I had to do was change it to a simple HTML table. So instead of …. I used:

… Now the designer is usable again!                                                   - after removing the ASP Table control, controls are accessible again Read MoreAdd comment Visual Studio Designer View Doesn’t Work After Adding a Table Reviewed by 0x000216 on Wednesday, September 01, 2010 Rating: 5 C# ResourceManager path By 0x000216 Read 0 Comments this is something that would have been nice for them to include on the MSDN page about the ResourceManager class in C#. a ResourceManager is used for localization b/c it allows you to read the right language string from .resx files that you've added to your application. you may find that you get this error message when trying to read a string out of a resource file: “Could not find any resources appropriate for the specified culture or the neutral culture. Make sure \"AppName.FileName.resources\" was correctly embedded or linked into assembly \"AppName\" at compile time, or that all the satellite assemblies required are loadable and fully signed.” the trick here is that you must include the VS project folder in the path when you instantiate the ResourceManager object. So if my assembly is "AppName" and my resource file called "FileName.resx" is under a folder called "FolderName," then the syntax looks like this: // Declare a Resource Manager for localized string resources private ResourceManager resManager = new ResourceManager("AppName.FolderName.FileName", System.Reflection.Assembly.GetExecutingAssembly()); note that you shouldn't include the file extension for the resource file. Read MoreAdd comment C# ResourceManager path Reviewed by 0x000216 on Thursday, April 02, 2009 Rating: 5 disabling VS just-in-time debugging By 0x000216 Read 0 Comments do you have Visual Studio installed on a machine that you use for every day tasks? are you tired of canceling the just-in-time debugging when you know that you're never going to use it on the apps that are triggering it? well, here's your post... turn it off. from: http://msdn2.microsoft.com/en-us/library/k8kf6y2a.aspx To enable/disable Just-In-Time debugging - On the Tools menu, click Options. - In the Options dialog box, select the Debugging folder. - In the Debugging folder, select the Just-In-Time page. - In the Enable Just-In-Time debugging of these types of code box, select or clear the relevant program types: Managed, Native, or Script. - To disable Just-In-Time debugging, once it has been enabled, you must be running with Administrator privileges. Enabling Just-In-Time debugging sets a registry key, and Administrator privileges are required to change that key. - Click OK. Read MoreAdd comment disabling VS just-in-time debugging Reviewed by 0x000216 on Friday, October 19, 2007 Rating: 5 Fatal error cannot open LIBC By 0x000216 Read 0 Comments When migrating Visual Studio projects from VS 2003 to VS 2005, I encountered the error: Fatal error cannot open "LIBC". I thought I'd post the solution to make it easier for others to find. To remove the error, navigate to Configuration Properties -> Linker -> Input. Then, add "libc" or "lib.lib" under Ignore specific library. In earlier versions of VS it was set to libc.lib. I found the reference on this page about migration issues: Migrating to Visual Studio 2005 Read MoreAdd comment Fatal error cannot open LIBC Reviewed by 0x000216 on Wednesday, November 22, 2006 Rating: 5 Calling a C++ lib from C# By 0x000216 Read 0 Comments a few months back, I found myself having to use a C++ .lib file from C#. it took a bit of looking around to figure it out, so I figured that I'd publish my cheat sheet here. I posted a number of questions about this subject to the C# interop newsgroup and found that the MVPs were excellent. if you search, you'll find these posts and be able to get better code from there - I've tried to get the examples in this post right, but the line breaks may cause confusion. BTW - I grabbed this stuff from all over. I've tried to credit the sources, but I may have missed some. I've created a separate post about handling the unsigned char* data type from a C .lib file. first of all, this is an awkward thing to do. if you have the choice, get a DLL instead of LIB. 1. create a C++ Win32 DLL Project from VS.Net from: http://www.codersource.net/win32_dlls.html Creating a Win32 dll: - Open the New Project Wizard. - Select Win32 Dynamic-Link Library. - Name the project "DemoDll." - In the next screen, select "A dll that exports some symbols" radio button. - Click Finish. The dll project will be created. Now open the file DemoDll.cpp. You can see a function definition for "DEMODLL_API int fnDemoDll(void)". Replace this function with the following code: DEMODLL_API int fnDemoDll(int a,int b){return a+b;} Open the DemoDll.h file and insert the declaration "DEMODLL_API int fnDemoDll(int a,int b)" Create a new file named "DemoDll.Def" and add the following code in that file. ; DemoDll.def : Declares the module parameters for the DLL. LIBRARY "DemoDll" DESCRIPTION 'DemoDll Windows Dynamic Link Library' EXPORTS ; Explicit exports can go here fnDemoDll PRIVATE Remember to add this DemoDll.def file to the project. Build the project. The DLL will be created. Using the DLL This part explains only the dynamic loading using loadlibrary. The following sample code has to be used in a new console application. #include #include typedef int (*ADDITIONFUNCTION)(int a,int b); ADDITIONFUNCTION addFunction; void main() { HINSTANCE hDll; hDll = LoadLibrary("Pathofdll"); if(hDll == NULL) { cout<<"Error loading win32 dll"<return ; } addFunction = (ADDITIONFUNCTION)GetProcAddress(hDll,"fnDemoDll"); int result; if(addFunction != NULL) cout<<(addFunction)(10,11)<http://www.codersource.net/win32_dlls.html Now open a blank solution, and add a new C++ MFC Class Library Project. Let's call it MyUnmanagedDotNetVCWrapper. We will implemenet a wrapper for MyUnmanagedVC6Class: #include "MyUnmanagedVC6Header.h" class __declspec(dllexport) MyUnmanagedDotNetClass { private: MyUnmanagedVC6Class* _class; public: MyUnmanagedDotNetClass(int x) { _class = new MyUnmanagedVC6Class(x); } void DoSomething(int x,double d) { _class->DoSomething(x,d); } } This should be located in MyUnmanagedDotNetHeader.h. Note: If you have all the sources for the original DLL you can open it in VisualStudio .NET, and it will convert it for you into a DLL you can use for the later step. This can save you the time for the first wrapper. 4. add methods to your new DLL that wrap the method in the original lib that you're trying to access from C#. newsgroup post about this topic. Random Notes: EXPORTS ; Explicit exports can go here MyMMCPropertyChangeNotify @1 MyMMCFreeNotifyHandle @2 MyMMCPropPageCallback @3 after this I added the following line to mymmc.h #pragma comment(lib, "mmc.lib") I changed one project setting and it compiled. In the General setting: Use MFC in a shared DLL. reference this page if you have questions about marshalling data types: http://msdn.microsoft.com/msdnmag/issues/02/08/CQA/ Example of syntax for calling the functions // Cawood: import an ARTag sample function [DllImport("ARTagWin32DLL.dll", EntryPoint="artag_create_marker_wrapped")] //public static extern int artag_create_marker_wrapped(int artag_id, int scale, unsigned char *image); public static extern int artag_create_marker_wrapped(int artag_id, int scale, [MarshalAs(UnmanagedType.LPStr)] StringBuilder image) Read MoreAdd comment Calling a C++ lib from C# Reviewed by 0x000216 on Friday, August 25, 2006 Rating: 5 .Net project location is not trusted By 0x000216 Read 0 Comments this just goes to show how quickly things change in software development - or maybe... how long I've been working on halo books. I was working on a C# WinForm project and I started to get a strange error when I opened the solution. the error is: "The project location is not trusted. Running the application may result in security exceptions when it attempts to perform actions which require full trust." it is possible to ignore the error and go about your business, but I was curious so I did some googling. it turns out that this issue is commonly associated with web apps or projects that are run from network drives. my project is a WinForm app on the C: drive, so this didn't help me. only after searching numerous pages did I find that there is a 'new' feature that applies security permissions downloaded zip files. this triggered some alarm bells because my app does use a sample project that I downloaded. anyway, the solution is easy. you must unblock the sample code before unzipping. to do this, right-click the Zip files, choose Properties, click UnBlock, click Apply and then unzip. this is probably common knowledge to those who work with sample code so it's sort of ironic. after all, I used to do that for a living. Read MoreAdd comment .Net project location is not trusted Reviewed by 0x000216 on Sunday, June 11, 2006 Rating: 5 C# Interop: unsigned char* C .lib By 0x000216 Read 0 Comments I ran into a situation where there was some C code in a .lib file that I wanted to access from C#. don't try this unless you have no other choice. ideally, you'll use a DLL instead of .LIB file. I've created a separate post about the process of creating a wrapper: Calling a C++ lib from C#. most of the .Net Interop examples don't include pointers being passed as out parameters, so it took me some time to work out the exact syntax for accessing the functions that I needed. hopefully, the next person who needs to do this will find this post. the solution was to use a C++ wrapper DLL (create a C++ Win32 DLL Project from VS.Net - remember to export symbols - http://www.codersource.net/win32_dlls.html) and call the wrapped functions from C#. you'll save yourself some hassle if you follow the steps in this tutorial for calling a sample function from a wrapper: http://www.codersource.net/win32_dlls.html. note: I changed one project setting to get it to compile. I changed the general project configuration setting "Use of MFC" to "Use MFC in a shared DLL." here is some sample code: C .lib ------------------- //create() will fill an unsigned char array with 100*scale*scale bytes //this function will malloc room if image is NULL //returns -1 if problem, 0 otherwise int create(int id, int scale, unsigned char *image); C++ Wrapper .cpp ------------------- WRAPPER_API int create_wrapped(int id, int scale, void** image) { int retCode = -1; unsigned char* ptrImage = NULL; if ( NULL != *image ) { ptrImage = (unsigned char*)GlobalLock(*image); retCode = create(id, scale, ptrImage); GlobalUnlock(*image); } else { retCode = create(id, scale, ptrImage); *image = (void*)ptrImage; } return retCode; } C++ Wrapper .def ------------------- LIBRARY Wrapper ; Wrapper.def : Declares the module parameters for the DLL. DESCRIPTION 'Wrapper Windows Dynamic Link Library' EXPORTS ; Explicit exports can go here ; Exporting the .lib functions init_wrapped @1 close_wrapped @2 create_wrapped @3 C++ Wrapper.h ------------------- // Add reference to library file #pragma comment(lib, "library.lib") C# Accessing the wrapper function ------------------- // create [DllImport("Wrapper.dll", EntryPoint="create_wrapped")]public static extern int create_wrapped(int id, int scale, [In][Out] ref IntPtr image); C# Using the data ------------------- // Allocate unmanaged memory - must be freed with Marshal.FreeHGlobal(ptrImage) IntPtr ptrImage = Marshal.AllocHGlobal(scale * scale * 100); // Copy the unmanaged bytes to a managed array try { // Get a pointer to an unmanaged byte array which contains the image // returns 0 for success label1.Text = create_wrapped(0, 5, ref Image).ToString(); byte[] ManagedArray = new byte[scale * scale * 100]; // Copy pointer into managed array Marshal.Copy(Image, ManagedArray, 0, ManagedArray.Length); // custom function to Write the image out to a file writeImageToFile(ManagedArray); } catch (ArgumentNullException ex) { MessageBox.Show(ex.Message, "Marshal Copy Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation); } finally { // Free the unmanaged memory Marshal.FreeHGlobal(Image); } Read MoreAdd comment C# Interop: unsigned char* C .lib Reviewed by 0x000216 on Tuesday, June 06, 2006 Rating: 5 Older Posts Home Recent Posts Facebook Created By Nexus · Powered by Blogger © All Rights Reserved Terms Of Service · Privacy Policy · Disclaimer · Contact Us · About Us