[vb .net] Flicker in rich text box?

[bangbang023 Veteran]

I have a rich text box control and I noticed, when typing, the contents flicker a bit. This doesn't happen in a plain textbox. Any ideas?

[Winston]

Hmmm try this, i can't see if it works because it doesn't flicker over here for me.

But make a new class file

paste this in it:

Public Class DoubleBufferRichTextBox

    Inherits System.Windows.Forms.RichTextBox

    Public Sub New()
        SetStyle(ControlStyles.DoubleBuffer, True)
        SetStyle(ControlStyles.AllPaintingInWmPaint, True)
    End Sub
    Public Event CustomPaint(ByVal e As PaintEventArgs)

    Protected Overrides Sub OnPaint(ByVal e As PaintEventArgs)

        RaiseEvent CustomPaint(e)

    End Sub

End Class

I'm not sure if it would work, because someone helped me out once with this, because my gradients inside a panel was flickering on resize, but Double Buffering had fixed this issue, not sure if it would work on Textboxes.

So once you've made that class above

go into the form where the actual RichTextBox control works

and where the Windows Form Generated Code is

look for where the RichTextBox is instantiated

i.e. should be something like

richTextBox = new System.Windows.Forms.RichTextBox

and just change it to

richTextBox = new DoubleBufferRichTextBox

[bangbang023 Veteran]

thanks I will try it in a bit and get back to you

[bangbang023 Veteran]

nope, it still flickers when typing in the box. I may just have to go back to a plain tetx box and forget some of the advanced features of the rich text box

[todd]

Do you have any code triggering when text is typed into the box?

[bangbang023 Veteran]

well I do but even when I disable it, still the same thing. I actually created a vanialla blank app with a rich text box and the same thing happens.

[Winston]

  bangbang023 said:

well I do but even when I disable it, still the same thing. I actually created a vanialla blank app with a rich text box and the same thing happens.

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This may sound dumb but, are you using a custom visual style?

I don't know because it seems like it's only happening to you, you can't eliminate the possibilities which might be causing this issue, have u tried sending the exe to a friend to see if they experience the same problem?

[bangbang023 Veteran]

Good idea but nope that didn't change anything.

[lexecutil]

Hm I can also see the flicker.. probably because I have a crap video card :p (It's only noticable when theres a large amount of text though).. I'll have a look and see if I can find a solution :p

Dan

EDIT: I took a look and it doesnt seem as though you can do much about this as the framework isnt actually drawing the richtextbox. :(.. I guess if the flickering is that big a problem then you will have to go back to the TextBox. :) (Hopfully I'm wrong :p)

Edited November 1, 2004 by dannyres

[bangbang023 Veteran]

damn that really sucks and yes the flickering is a huge problem for me. back to textbox it is :(

[Winston]

  bangbang023 said:

damn that really sucks and yes the flickering is a huge problem for me. back to textbox it is :(

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can i see this flicker post a sample exe please.

[bangbang023 Veteran]

just download nexpad 0.3 from my sig.

[Winston]

very subtle flickering, strange, it doesnt happen to me, u must be doing something in the background.

[bangbang023 Veteran]

nothing is going on in the background. Just my usual apps running, nothing that uses cpu much, just my IM programs.

[Winston]

LOL no no i meant inside the application, what events have you subscribed to in respect to the rich text box?

[bangbang023 Veteran]

well i have the line number counter but that's it really. For testing, I disabled all events related to the text box that would be triggered automatically and still flickers.

[Winston]

hmmmm do u have a LCD? lol this sounds irrelevant but it took me a while till i finally saw the flickering, it only happened once in a blue moon.

[bangbang023 Veteran]

nope regular crt set at 85hz refresh. This is mind bloggling to me but the flickering drives me up the wall and back down again.

[vcv]

Sorry, but most versions of RichEdit simply flicker. It's a poorly written control and the MS coders were too lazy to properly use a back buffer. It has nothing to do with monitor, video card, or refresh rate.

The only thing I can suggest is messing with the window styles for the parent window and the rich edit window itself.

WS_CLIPCHILDREN for the parent and WS_CLIPSIBLINGS for the rich edit.

As well, CS_HREDRAW and CS_VREDRAW should not be classed as class styles for RegisterClassEx.

Edited November 1, 2004 by vcv

[bangbang023 Veteran]

  vcv said:

Sorry, but most versions of RichEdit simply flicker.  It's a poorly written control and the MS coders were too lazy to properly use a back buffer.  It has nothing to do with monitor, video card, or refresh rate.

The only thing I can suggest is messing with the window styles for the parent window and the rich edit window itself.

WS_CLIPCHILDREN for the parent and WS_CLIPSIBLINGS for the rich edit.

As well, CS_HREDRAW and CS_VREDRAW should not be classed as class styles for RegisterClassEx.

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I figured it had to be the control after all. Thanks.