ApplicationContext to run background task

Many of times we need to create an application which need to run in background and doesn’t require a form or a GUI. We have an option of creating a Windows Service but sometime it’s difficult to use it for a normal user. So in this situation we have an option of creating an application by inheriting a ApplicationContext class which is available in Windows Form.

To create a project to run a background task we can perform following steps

1. Create a new Windows Form project
2. Delete the available Forms and Application class.
3. Create a new class which will inherit ApplicationContext where we can perform background task.
4. Create a new module which will contain main method to run the application.

Below is a simple example where we are inheriting ApplicationContext class. In the constructor of class we are starting a new thread where we can perform some long running task and when the task get completed we can call ExitThread which will close the application.

Public Class CustomApplicationContext
    Inherits ApplicationContext

    Public Sub New()
        MyBase.New()

        Try
            Dim th As New Thread(AddressOf StartBackgroundTask)
            th.Start()
        Catch ex As IOException
            ExitThread()
        End Try
    End Sub

    Private Sub StartBackgroundTask()
        Try
            'Some background Task
            For i As Integer = 0 To 5
                Threading.Thread.Sleep(1000)
            Next
        Finally

            'Task completed. Close the application
            ExitThread()
        End Try
    End Sub
End Class

We also have to create a new Module which will contain Main method to start the application using Application.Run and having CustomApplicationContext class as it’s parameter.

Module MainModule
    Public Sub Main()
        Dim context As New CustomApplicationContext
        Application.Run(context)
    End Sub
End Module

Download Code: CustomApplicationContext.rar