Removing a collection of controls

Question

I have a form (Form1) and it has 30 controls. When I hit a button, I want to remove those 30 buttons and put other controls on the form. Now, my problem is that this is to slow. I have this list with controls I want to delete and I run through them with a For Each. ``` Private Sub ClearControls() 'removing the controls from Me.Controls For Each Control As Control In ListToDelete Me.Controls.Remove(Control) Next ListToDelete = New List(Of Control) End Sub ``` Now, if you watch the form, you see the controls getting deleted 1 by 1. This action takes about 0.4 seconds (timed with the build-in stopwatch) and that's too long. Are there any solutions to delete the controls in a faster way or is it only possible to delete the controls 1 by 1? Maybe an important fact is that everything is connected with a database. The controls are created by a class I defined myself (TableDrawer) and it creates a rectangle or circle (depends on info from the database). I add the selfmade controls to the form…

Accepted Answer

Hiding the Panel first seems to make the controls disappear quicker than just clearing the Panel. See this code:

```
Option Strict On

Public Class Form1

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Panel1.Visible = False

If Not Panel1.Controls.OfType(Of Button).Any() Then
            For x As Integer = 1 To 10
                For y As Integer = 1 To 10
                    Dim btn As New Button()
                    btn.Size = New Size(45, 45)
                    btn.Location = New Point((x - 1) * 45, (y - 1) * 45)
                    btn.Text = (x * y).ToString()
                    Panel1.Controls.Add(btn)
                    btn.Visible = True
                Next
            Next
        End If

Panel1.Visible = True
    End Sub

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
        Panel1.Visible = False
        Panel1.Controls.Clear()
        Panel1.Visible = True
    End Sub
End Class
```

This code has 2 buttons, and a Panel. Button1 generates 100 buttons, places them on a Panel. Button2 hides the panel before removing them. Perhaps you can experiment with this idea.

Removing a collection of controls

Solution

Problem