Visual Basic .NET/IDisposable

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[edit] The IDisposable Interface

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[edit] Basics

The IDisposable interface is implemented when an object needs to be "cleaned up" after use. If an object has a "Dispose" method, then it needs to be cleaned up after use.

The easiest way to clean up this sort of object is by using the VB keyword "Using".

   Using f As New Form
       f.Show
   End Using

When an IDisposable object is a form-level variable, it should be disposed in the Form_Closed event.

   Public Class Form1
       Private mfrmChild As Form

    
       Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
           mfrmChild = New Form
           mfrmChild.Text = "Child"
           mfrmChild.Show()
       End Sub

    
       Private Sub frmMain_FormClosed(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
           mfrmChild.Dispose()
       End Sub
   End Class