Doubt about how to implement a C# Dependency Injection using Ninject

Question

I have a C# project with Windows Forms. I have a question about how to make an implementation between two layers of my application: Application and WindowsForms.

I need to carry one DataGridView with a list of "PessoaTipo".

I created an instance of my Application class PessoaTipoAppService in the WindowsForms and called the function _PessoaTipoApp.GetAll(), only when I carry builder, fails to implement Dependency Injection with Ninject.

public partial class Form1 : Form
    {
        private readonly IPessoaTipoAppService _PessoaTipoApp;

        public Form1(IPessoaTipoAppService PessoaTipoApp)
        {
            InitializeComponent();

            _PessoaTipoApp = PessoaTipoApp;

            dataGridView1.DataSource = _PessoaTipoApp.GetAll();
        }
    }

Will someone give me a hand? I left the project available for download. Here we can post the solution here in this topic...

https://onedrive.live.com/? id=40838E65B9F8787E%21120&Cid=40838E65B9F8787E

Answer 1

Minimal Example:

Install the package by Nuget or Package Manager Console

Install-Package Ninject

Create a class that is responsible for solving dependencies:

FormModule

using Ninject.Modules;
public class FormModule : NinjectModule
{
    public override void Load()
    {
        Bind<IMount>().To<Mount>();
    }

    public static FormModule Create()
    {
        return new FormModule();
    }
}

in the method Load call the Bind for class configuration and put all classes that will be used in your project and that are dependencies of other forms.

---

Create a class that will be responsible for instantiating Form and consequently the their dependencies:

FormResolve

using Ninject;
using Ninject.Modules;
public class FormResolve
{
    private static IKernel _ninjectKernel;

    public static void Wire(INinjectModule module)
    {
        _ninjectKernel = new StandardKernel(module);
    }

    public static T Resolve<T>()
    {
        return _ninjectKernel.Get<T>();
    }
}

In the archive Program.cs configure as follows:

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);

            FormResolve.Wire(FormModule.Create());
            Application.Run(FormResolve.Resolve<Form1>());
        }    
    }
}

With these two classes and the configuration done in the Program.cs is already ready to solve dependencies.

Example: Form1

using Ninject;
using System.Windows.Forms;  
namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {

        private IMount Mount { get; set; }

        [Inject()]
        public Form1(IMount mount)
        {
            InitializeComponent();
            Mount = mount;
        }

        private void Form1_Load(object sender, System.EventArgs e)
        {
            label1.Text = Mount?.GetDateTime().ToLongDateString();

        }

        private void button1_Click(object sender, System.EventArgs e)
        {
            Form2 frm = FormResolve.Resolve<Form2>();
            frm.ShowDialog();
        }
    }
}

---

To call the form2 or any form follow the example of the button below where form1 calls the form2:

private void button1_Click(object sender, System.EventArgs e)
{
    Form2 frm = FormResolve.Resolve<Form2>();
    frm.ShowDialog();
}

References:

• Ninject
• Dependency Injection in Winforms using Ninject and Entity Framework
• How to use Ninject in a Windows Forms application?