[RESOLVED] Listview flashing while updated

[batori]

Hi,

I have a timer that changes the value of a listview subitem,costantly

While the update happends the listview flashed which is annoying..

What is interesting for me is that, while the update of the listview is happening i can resize the Form and while resizing the form the listview does not flash

My question would be, is there a way to fix that so i dont have the listview flashing while the form si not being resized?

I tried the lock api but that didnt work.


Cheers!

[RhinoBull]

It shouldn't flash unless you use ListView1.Refresh method.

[batori]

the list itself does not flash...it's the column headers mostly...

i dont have the refresh method in the code ...

still, while i resize the form the listview does not flash a bit :/ straange

thanks for replying

[RhinoBull]

I noticed that listview would flash if form's AutoRedraw = True. Check that and turn it off if it's on.

[batori]

My AutoRedraw is set to False

I still dont know what do to, maybe a sub to make constant minor form resizing ?

[RhinoBull]

You did mention that you tried using Lock (as you said) api but it didn't help.
I tried running this quick sample and there was not a single flash so create new project and run this:

Option Explicit

Private Declare Function LockWindowUpdate Lib "user32" (ByVal hwndLock As Long) As Long

Private Sub Form_Load()
    Me.AutoRedraw = False
    
    'add column headers here
    
    ListView1.ListItems.Add , , "Item1"
    ListView1.ListItems.Add , , "Item2"
    ListView1.ListItems.Add , , "Item3"
End Sub

Private Sub Command1_Click()
    Timer1.Interval = 500
End Sub

Private Sub Timer1_Timer()
Static i As Long

    LockWindowUpdate ListView1.hWnd
    
    i = i + 1
    ListView1.ListItems(2).SubItems(1) = "Value " & i
    
    LockWindowUpdate False

End Sub

[batori]

the flashing seems to be gone, but if you put the timer interval as 10 or 5 the flashing comes out again....

i work with very very small intervals....

my hopes start to fade away

RhinoBull ,i really appreciate your work here.

[RhinoBull]

Utilizing Before/AfterLabelUpdate and Sleep api makes it less flickering. Give it the try:

Option Explicit

Private Declare Function LockWindowUpdate Lib "user32" (ByVal hwndLock As Long) As Long
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)

Private Sub Form_Load()
    Me.AutoRedraw = False
    
    'add column headers here
    
    ListView1.ListItems.Add , , "Item1"
    ListView1.ListItems.Add , , "Item2"
    ListView1.ListItems.Add , , "Item3"
End Sub

Private Sub Command1_Click()
    Timer1.Interval = 10
End Sub

Private Sub ListView1_AfterLabelEdit(Cancel As Integer, NewString As String)
    LockWindowUpdate False
End Sub

Private Sub ListView1_BeforeLabelEdit(Cancel As Integer)
    LockWindowUpdate ListView1.hWnd
End Sub

Private Sub Timer1_Timer()
Static i As Long

    LockWindowUpdate ListView1.hWnd
    
    i = i + 1
    ListView1.ListItems(2).SubItems(1) = "Value " & i
    
    Sleep 10
    LockWindowUpdate False

End Sub

[batori]

Thanks man, it did really help alot!!

Thanks again for your kind help.


Rated ))

[RhinoBull]

Alright, sounds better this time...