CODEWITHSUNDEEP
c#.netwinformslistview
James
James

Reputation: 4354

Blurry Text with C# Listview when reducing flicker

I have a System.Windows.Forms.ListView containing numerous items. It was flickering intolerably (as seems to often be the case) so after some searching I decided to do these 2 things in a "ListViewLessFlicker" class.

        this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, true);
        this.SetStyle(ControlStyles.Opaque, true);

DoubleBuffering didn't have much effect even though it's most commonly given as the solution in these topics, but setting the style opaque to true hugely reduced flickering.
http://www.virtualdub.org/blog/pivot/entry.php?id=273

However it had a side-effect that I can't seem to find a fix for. When I hover my mouse over an item in the ListView it now makes the text bold and very blurry (this doesn't happen unless opaque is true).

Here is a very zoomed in example.

enter image description here

If anybody has a fix or knows why it may be doing this I'd love to know!

Upvotes: 3

Views: 731

Answers (2)

Yorgi
Yorgi

Reputation: 187

I had the same problem as you and I found solution in the comments on this page: http://www.virtualdub.org/blog/pivot/entry.php?id=273

You have to create new class like this:

public class BufferedListView : ListView
{
    public BufferedListView() : base()
    {
        SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
    }
}

and then define your ListView as BufferedListView like this:

ListView myListView = new BufferedListView();

After that blurry text is not a problem any more ;)

Upvotes: 3

xxbbcc
xxbbcc

Reputation: 17327

I usually do this - reduces flickering when resizing the control. You need to use BeginUpdate() / EndUpdate() to reduce flickering when adding items in bulk. I don't know what may cause the blurring, so I can't advise about that - updatig your video driver may help but don't hold your hopes high.

[System.ComponentModel.DesignerCategory ( "" )]
public partial class ListViewEx : ListView
{
    private const int WM_ERASEBKGND = 0x14;

    public ListViewEx ()
    {
        InitializeComponent ();

        // Turn on double buffering.
        SetStyle ( ControlStyles.OptimizedDoubleBuffer |
            ControlStyles.AllPaintingInWmPaint, true );

        // Enable the OnNotifyMessage to filter out Windows messages.
        SetStyle ( ControlStyles.EnableNotifyMessage, true );
    }

    protected override void OnNotifyMessage ( Message oMsg )
    {
        // Filter out the WM_ERASEBKGND message to prevent the control
        // from erasing the background (and thus avoid flickering.)
        if ( oMsg.Msg != WM_ERASEBKGND )
            base.OnNotifyMessage ( oMsg );
    }
}

Upvotes: 5

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