Increasing performance of windows forms with multiple controls

Question

Hello,

I am currently developing a windows app, which has at least 400 controls and a lot more events and actions.
However, now that I have started coding, with 25 controls itself, the winform is beginning to decline its performance by showing lag, while executing and also while coding especially while dragging and dropping controls on the designer tab (takes at least 15 seconds to display).
I have been using multiple forms, but still facing the same problem.

Please help me guide you to overcome this error.

Thank you in advance.

Answer 1

From comments,
a test with 400 images in a ScrollViewer embedded with ElementHost (+ a click event) =>

Add the 4 references first :

    ' Add reference to PresentationFramework  
    ' Add reference to PresentationCore  
    ' Add reference to WindowsBase  

    ' Add reference to WindowsFormsIntegration  
    ' Add Imports System.Windows.Forms.Integration  

Test :

Imports System.Windows.Forms.Integration  
  
Public Class Form1  
  
    Dim nImageWidth As Double = 0  
    Dim nImageHeight As Double = 0  
  
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load  
        If True Then  
            Dim nWidth As Double = 600, nHeight As Double = 400  
  
            Dim gridMain As System.Windows.Controls.Grid = New System.Windows.Controls.Grid()  
            gridMain.Background = System.Windows.Media.Brushes.White  
  
            Dim scrollViewer1 As New System.Windows.Controls.ScrollViewer  
            scrollViewer1.HorizontalScrollBarVisibility = System.Windows.Controls.ScrollBarVisibility.Auto  
  
            Dim grid1 As New System.Windows.Controls.Grid  
            grid1.HorizontalAlignment = System.Windows.HorizontalAlignment.Left  
            grid1.VerticalAlignment = System.Windows.VerticalAlignment.Top  
  
            Dim sTempPath As String = System.IO.Path.GetTempPath()  
            sTempPath = String.Concat(sTempPath, "Hulk.jpg")  
            Using wc As New System.Net.WebClient()  
                wc.DownloadFile(New Uri("https://i.ibb.co/WVfdcJb/hulk.jpg"), sTempPath)  
            End Using  
            Dim sImageFileName As String = sTempPath  
            Dim bmp1 As System.Windows.Media.Imaging.BitmapImage = New System.Windows.Media.Imaging.BitmapImage(New Uri(sImageFileName, UriKind.Absolute))  
            sTempPath = System.IO.Path.GetTempPath()  
            sTempPath = String.Concat(sTempPath, "Schtroumpfette.jpg")  
            Using wc As New System.Net.WebClient()  
                wc.DownloadFile(New Uri("https://i.ibb.co/52Lz2mk/Schtroumpfette.jpg"), sTempPath)  
            End Using  
            sImageFileName = sTempPath  
            Dim bmp2 As System.Windows.Media.Imaging.BitmapImage = New System.Windows.Media.Imaging.BitmapImage(New Uri(sImageFileName, UriKind.Absolute))  
            Dim imgArray() As System.Windows.Controls.Image = New System.Windows.Controls.Image(400 - 1) {}  
            nImageWidth = Math.Max(bmp1.PixelWidth, bmp2.PixelWidth)  
            nImageHeight = Math.Max(bmp1.PixelHeight, bmp2.PixelHeight)  
            Dim i As Integer = 0  
            Dim nX As Double = 0, nY As Double = 0  
            Do While (i < imgArray.Length)  
                Dim img1 As System.Windows.Media.Imaging.BitmapImage  
                If (i Mod 2 = 0) Then  
                    img1 = bmp1  
                Else  
                    img1 = bmp2  
                End If  
                imgArray(i) = New System.Windows.Controls.Image()  
                imgArray(i).Source = img1  
                imgArray(i).Width = nImageWidth  
                imgArray(i).Height = nImageHeight  
                imgArray(i).Margin = New System.Windows.Thickness(nX, nY, 0, 0)  
                imgArray(i).HorizontalAlignment = System.Windows.HorizontalAlignment.Left  
                imgArray(i).VerticalAlignment = System.Windows.VerticalAlignment.Top  
                nX += nImageWidth  
                grid1.Children.Add(imgArray(i))  
                AddHandler imgArray(i).MouseDown, AddressOf Image_MouseDown  
                i += 1  
                If (i Mod 10 = 0) Then  
                    nY += nImageHeight  
                    nX = 0  
                End If  
            Loop  
  
            scrollViewer1.Content = grid1  
            gridMain.Children.Add(scrollViewer1)  
  
            Dim elementHost1 As ElementHost = New ElementHost() With {  
                .Child = gridMain,  
                .Location = New System.Drawing.Point(10, 10),  
                .Size = New System.Drawing.Size(CInt(nWidth), CInt(nHeight)),  
                .BackColor = System.Drawing.Color.Yellow  
            }  
            Me.Controls.Add(elementHost1)  
            Return  
        End If  
    End Sub  
  
    Private Sub Image_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Input.MouseButtonEventArgs)  
        Dim img As System.Windows.Controls.Image = TryCast(sender, System.Windows.Controls.Image)  
        If (e.LeftButton = 1) Then  
            Dim nX As Double = img.Margin.Left / nImageWidth  
            Dim nY As Double = img.Margin.Top / nImageHeight  
            MessageBox.Show(String.Format("Image ({0} - {1}) clicked", nX.ToString(), nY.ToString()), "Information", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)  
        End If  
    End Sub  
End Class