Wednesday, September 30, 2020

Fedora 32 : Can be better? part 014.

The GTK documentation for C # is not very up to date, I tried to use a button to change a label and I failed first time. The Fedora team could improve this to develop the development side. Here's what I've managed to do so far with GTK.

I fixed the source code with this, but I would have preferred a better method:

my_Button.Clicked += delegate {
my_Label.Text = "Use delegate!";
};

Mono is a free and open source implementation of the .NET Framework.

The most popular build tool for Mono is NAnt.

NUnit is very useful for test driven development.

[root@desk mythcat]# dnf install mono-devel
Last metadata expiration check: 0:15:26 ago on Wed 30 Sep 2020 09:04:30 PM EEST.
Package mono-devel-6.6.0-8.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!
[root@desk mythcat]# dnf install nant
...
Installed:
  log4net-2.0.8-10.fc32.x86_64            nant-1:0.92-25.fc32.x86_64           
  nunit2-2.6.4-24.fc32.x86_64            

Complete!
[root@desk mythcat]# dnf install nunit nunit-gui
Last metadata expiration check: 0:02:09 ago on Wed 30 Sep 2020 09:27:18 PM EEST.
No match for argument: nunit-gui
Error: Unable to find a match: nunit-gui

Installing MonoDevelop:

[root@desk mythcat]# dnf install monodevelop
...
Installed:
  ORBit2-2.14.19-23.fc32.x86_64                                                 
  gamin-0.1.10-36.fc32.x86_64                                                   
  gnome-desktop-sharp-2.26.0-36.fc31.x86_64                                     
  gnome-sharp-2.24.2-25.fc32.x86_64                                             
  gnome-vfs2-2.24.4-30.fc32.x86_64                                              
  gnome-vfs2-common-2.24.4-30.fc32.noarch                                       
  gtk-sharp2-2.12.45-11.fc32.x86_64                                             
  gtk-sharp2-devel-2.12.45-11.fc32.x86_64                                       
  gtksourceview2-2.11.2-31.fc32.x86_64                                          
  libIDL-0.8.14-21.fc32.x86_64                                                  
  libbonobo-2.32.1-18.fc32.x86_64                                               
  libbonoboui-2.24.5-18.fc32.x86_64                                             
  libgnome-2.32.1-20.fc32.x86_64                                                
  libgnome-keyring-3.12.0-19.fc32.x86_64                                        
  libgnomecanvas-2.30.3-19.fc32.x86_64                                          
  libgnomeui-2.24.5-21.fc32.x86_64                                              
  mono-addins-1.1-13.fc32.x86_64                                                
  monodevelop-5.10.0-17.fc32.x86_64                                             
  vte-0.28.2-31.fc32.x86_64                                                     

Complete!

Install the .NET Core. This is a general-purpose, modular, cross-platform and open-source development Platform.

[root@desk mythcat]# dnf copr enable @dotnet-sig/dotnet
Enabling a Copr repository. Please note that this repository is not part
of the main distribution, and quality may vary.
...
Do you really want to enable copr.fedorainfracloud.org/@dotnet-sig/dotnet? [y/N]: y
Repository successfully enabled.
[root@desk mythcat]# dnf install dotnet
Copr repo for dotnet owned by @dotnet-sig             5.4 kB/s | 3.3 kB     00:00    
Package dotnet-3.1.108-1.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete! 

Let's start with a GTK project using the MonoDevelop I.D.E.

[mythcat@desk ProjectsCSharp]$ monodevelop 
I use a new solution from .NET with GTK# 2.0 Project template. The default source code is this:
using System;
using Gtk;

namespace MonoDevelopGTK_001
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			Application.Init ();
			MainWindow win = new MainWindow ();
			win.Show ();
			Application.Run ();
		}
	}
}
The result is an simple window form. For a complex form with entry ,label and one button, you can see the next example:
using System;
using Gtk;

namespace MonoDevelopGTK_001
{
	
	class MainClass
	{
		public static void Main (string[] args)
		{
			// define here Entry and Button 
			Entry name;
			Button my_Button;

			Application.Init ();
			MainWindow win = new MainWindow ();
			// change the size of window
			win.SetDefaultSize (640, 480);
			// this will close application
			win.DeleteEvent += new DeleteEventHandler (Window_Delete);

			// use of VBox or HBox
			VBox global_vbox = new VBox();
			win.Add(global_vbox);
			name = new Entry();
			global_vbox.PackStart(name, false, false, 0);
			win.Add(name);

			VBox label_vbox = new VBox();
			global_vbox.Add (label_vbox);
			//Define here a label and put some text in it.
			Label my_Label = new Label();
			my_Label.Text = "Hello World!";
			label_vbox.PackStart(my_Label, false, false, 0);
			//Add the label to the form
			win.Add(my_Label);

			VBox button_vbox = new VBox();
			global_vbox.Add (button_vbox);
			my_Button = new Button("Ok!");
			my_Button.Clicked += OnButtonClicked;
			button_vbox.PackStart(my_Button, false, false, 0);
			win.Add(my_Button);
			// ShowAll is used to see all labels, buttons
			win.ShowAll();
			//win.Show ();
			Application.Run ();

		}

		public static void OnButtonClicked (object obj, EventArgs args)
		{
			//Label my_Label = obj as Gtk.Label;
			Console.WriteLine ("Button Clicked !");

		}

		static void Window_Delete (object obj, DeleteEventArgs args)
		{
			Application.Quit ();
			args.RetVal = true;
		}
	}
}