Krypton resizing issue

First, you need to get where the user clicked before dragging mouse down event of splitter control

and total width

from three controls:

Private mouse_Down As Point //you can use an integer also because y coordinate remains the same
Private totalWidth As Integer

//mouse down event
mouse_Down.X = e.MouseCursorX
totalWidth = seperator.Width + LeftControl.Width + RightControl.Width

Private Sub KryptonSeparator1_SplitterMoving(ByVal sender As Object, ByVal e As SplitterCancelEventArgs) Handles KryptonSeparator1.SplitterMoving

    Dim separator As KryptonSeparator = DirectCast(sender, KryptonSeparator)
    Dim leftCtrl As Control = Control1
    Dim rightCtrl As Control = Control2
    Dim leftWidth, rightWidth As Integer

    leftWidth = leftCtrl.Width + (e.MouseCursorX - mouse_Down.X)
    rightWidth = rightCtrl.Width - (e.MouseCursorX - mouse_Down.X)

    If leftWidth <= leftCtrl.MinimumSize.Width Then
        leftCtrl.Width = leftCtrl.MinimumSize.Width
        separator.Left = leftCtrl.Left + leftCtrl.MinimumSize.Width
        rightCtrl.Left = leftCtrl.Left + leftCtrl.MinimumSize.Width + separator.Width
        rightCtrl.Width = totalWidth - leftCtrl.MinimumSize.Width - separator.Width

        Return
    End If

    If rightWidth <= rightCtrl.MinimumSize.Width Then
        leftCtrl.Width = totalWidth - rightCtrl.MinimumSize.Width - separator.Width
        separator.Left = leftCtrl.Left + leftCtrl.Width
        rightCtrl.Left = leftCtrl.Left + leftCtrl.Width + separator.Width
        rightCtrl.Width = rightCtrl.MinimumSize.Width

        Return
    End If

    separator.Left += (e.MouseCursorX - mouse_Down.X)
    leftCtrl.Width = leftWidth
    rightCtrl.Width = rightWidth
    rightCtrl.Left = leftCtrl.Left + leftWidth + separator.Width

End Sub

      

        
        
        
      

    

EDIT

Try the following:

//mouse down event
//mouse_Down.X = e.MouseCursorX
mouse_Down.X = MousePosition.X
mouse_Down.Y = MousePosition.Y
mouse_Down = seperator.PointToClient(mouse_Down)

totalWidth = seperator.Width + LeftControl.Width + RightControl.Width

      

        
        
        
      

    

and SplitterMoving

:

Dim leftWidth, rightWidth As Integer
Dim pnt As Point

pnt.X = MousePosition.X
pnt.Y = MousePosition.Y

pnt = seperator.PointToClient(pnt)

//replace e.MouseCursorX with pnt.X
... 

      

        
        
        
      

    

EDIT 2

There are two minor bugs in your logic for resizing two windows:

• Using e.MouseCursorX
  
  to determine the direction of resizing (left or right) is incorrect, for example, you move the cursor to the left (left) while staying inside the separator, e.MouseCursorX
  
  is still positive, so you resize to the right (until, of course, e.MouseCursorX becomes negative) instead of left !
• Your code checks for the minimum size, but does nothing when the comparison is false, which means the resulting size of the control is smaller. When this happens, you need to set the size of the control, for example, let's say the minimum size is 50 and the size of controls is 55. If the size changes very quickly, the resulting size of the control may become 49. Your code does nothing (comparison incorrect) and the size of the control remains 55 instead of setting it to 50.

My solution addresses both of these situations. However, the real problem with your terrible effect, as you said, is not these two errors. In fact, the application response is too slow when resizing controls. To be more specific when you resize and move the control to the right (ListBox_Files). You can check it yourself if you drag and drop a small number (1 or 2) files and see the result. This is an amazing difference. This, unfortunately, tells me that there is nothing you can do about it. You need to change your sizing logic. Two solutions:

• Use a single control and custom graphic, text, icons, vertical-horizontal scrollbars, etc. (Not recommended!)
• Make a visual studio and other app. Don't resize the controls until you release the button. Just show a vertical line: