Increasing memory usage while scrolling on listview items in vb.net - vb.net

Question

In a WinForm i have two listview(lvwTemplateCategory) one is listing folders at given directory and if you select folder, other listview(lvwTemplates) shows the files under this directory. I have also one picturebox(picTemplateImage) to show preview screenshot of that file.
While i'm scrolling on that form for 2-3 folders and 9-10 files it's memory usage goes from 62 MB to 120 MB.
I don't know how to manage the memory source also i tried to implement IDisposable but not know where to implement.
P.S. I'm using VS 2017 and calling that WinForm with .Show() method.
Also if you see non-logic codes please let me know.
Option Explicit On
Option Strict On
Imports System.IO
Public Class frmCreateNewModel
Implements IDisposable
Private Sub LoadForm(sender As Object, e As EventArgs) Handles MyBase.Load
Call AddRootDatabase()
splCreateNewModel.Panel2Collapsed = True
Size = New Size(946, 800)
End Sub
Private Sub ViewLargeIcons(sender As Object, e As EventArgs) Handles cmdViewLargeIcons.Click
lvwTemplateCategory.View = View.LargeIcon
End Sub
Private Sub ViewListIcons(sender As Object, e As EventArgs) Handles cmdViewList.Click
lvwTemplateCategory.View = View.List
End Sub
Private Sub AddRootDatabase()
Try
Dim DirDB As String = My.Settings.str_db__path_tpl
Dim DirInfoDB As New DirectoryInfo(DirDB)
For Each TplDirDB As DirectoryInfo In DirInfoDB.GetDirectories
If Not (TplDirDB.Attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
cboTemplateDatabase.Items.Add(TplDirDB.Name)
End If
Next
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub SelectRootDatabase(sender As Object, e As EventArgs) Handles cboTemplateDatabase.SelectedIndexChanged
Try
lvwTemplateCategory.Items.Clear()
lvwTemplates.Items.Clear()
Dim DirTempRootDir As String = My.Settings.str_db__path_tpl & "\" & cboTemplateDatabase.SelectedItem.ToString
Dim DirTempDbInfo As New DirectoryInfo(DirTempRootDir)
Dim lstIcon As Integer
For Each TplCatDir As DirectoryInfo In DirTempDbInfo.GetDirectories
If Not (TplCatDir.Attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
If imgIcons.Images.ContainsKey(TplCatDir.Name) = True Then
lstIcon = imgIcons.Images.IndexOfKey(TplCatDir.Name)
Else
lstIcon = imgIcons.Images.IndexOfKey("default")
End If
lvwTemplateCategory.Items.Add(TplCatDir.Name, lstIcon)
End If
Next
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub SelectTemplateCategory(sender As Object, e As EventArgs) Handles lvwTemplateCategory.SelectedIndexChanged
If (CInt(lvwTemplateCategory.SelectedItems.Count.ToString) = 0) Then
Return
End If
Dim DirTempCatDir As String = My.Settings.str_db__path_tpl & "\" & cboTemplateDatabase.SelectedItem.ToString & "\" & lvwTemplateCategory.SelectedItems(0).Text.ToString
Dim DirTempInfo As New DirectoryInfo(DirTempCatDir)
lvwTemplates.Items.Clear()
Try
For Each TplFile As FileInfo In DirTempInfo.GetFiles
If Not (TplFile.Attributes And FileAttributes.Hidden) = FileAttributes.Hidden Then
If Path.GetExtension(TplFile.Name) = ".spck" Or Path.GetExtension(TplFile.Name) = ".buspck" Then
lvwTemplates.Items.Add(TplFile.Name)
End If
End If
Next
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub SelectTemplate(sender As Object, e As EventArgs) Handles lvwTemplates.SelectedIndexChanged
If (CInt(lvwTemplates.SelectedItems.Count.ToString) = 0) Then
cmdQuickConfigure.Enabled = False
Return
End If
cmdQuickConfigure.Enabled = True
Dim TemplFileName As String = Path.GetFileNameWithoutExtension(lvwTemplates.SelectedItems(0).Text.ToString)
Dim DirTempDir As String = My.Settings.str_db__path_tpl & "\" & cboTemplateDatabase.SelectedItem.ToString & "\" & lvwTemplateCategory.SelectedItems(0).Text.ToString & "\" & TemplFileName
Dim imagePath As String = DirTempDir & ".png"
If File.Exists(imagePath) Then
picTemplateImage.ImageLocation = (imagePath)
picTemplateImage.SizeMode = PictureBoxSizeMode.StretchImage
picTemplateImage.Load()
Else
picTemplateImage.Image = picTemplateImage.ErrorImage
End If
txtModelName.Text = lvwTemplates.SelectedItems(0).Text.ToString
End Sub
Private Sub VisualViewControl(sender As Object, e As EventArgs) Handles cmdVisualControl.Click
If splCreateNewModel.Panel2Collapsed = False Then
splCreateNewModel.Panel2Collapsed = True
Size = New Size(946, 800)
cmdVisualControl.Text = ">>"
Else
cmdVisualControl.Text = "<<"
splCreateNewModel.Panel2Collapsed = False
Size = New Size(1300, 800)
End If
End Sub
Private Sub BrowseDirectory(sender As Object, e As EventArgs) Handles cmdBrowseDirectory.Click
Try
Dim sfd As New SelectFolderDialog With {
.Title = "Select a folder"
}
If sfd.ShowDialog(Me) = DialogResult.OK Then
txtModelDirectory.Text = sfd.FolderName
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
Private Sub DialogOK(sender As Object, e As EventArgs) Handles cmdOk.Click
CreateModel()
Close()
End Sub
Private Sub DialogCancel(sender As Object, e As EventArgs) Handles cmdCancel.Click
Close()
End Sub
End Class