Sign in
Microsoft.com
 
Expression > Forums Home > Related Technologies Forums > Windows Presentation Foundation (WPF) > 2010: CacheMode for ListViewItem?
Ask a questionAsk a question
Search Forums:
 

Answer2010: CacheMode for ListViewItem?

  • Friday, October 30, 2009 3:41 PMJustTom Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     
    Sign In to Vote
    0
    Sign In to Vote
    Hello,

    it just occurs to me that in my problematic ListView (40 items long, scrolling a LOT downward as data drops in on the top - a LOT)... I may actually win a lot by caching the indivisual lines (ListViewItems) with the CacheMode property introduced in 4.0 ;) It would mean after a scroll the line could only be redrawrn from bitmap, not from the elements... may make sense ;)

    Setting CacheMode on the complete list is not good, as it scrolls down, so it invalidates completely every time.

    Anyone can help me out how to set that?

    I dont define a complete style so far - I am more than happy with the standard. I define an ItemCntainerStyle, but it basically sets HorizontalContentAlignment AND has a lot of datatrigger color changes.

    Is there a way to access the CacheMode property of the ListViewItem at the ItemContainerStyle? Or how else (yeah, willing to learn) can I do that?
     

Answers

  • Wednesday, November 04, 2009 3:01 AMBrendan Clark - MSFT Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     Answer
    Sign In to Vote
    0
    Sign In to Vote
    I suppose I don't understand the problem here.  ListViewItem is a Control, which is a UIElement, so you should be able to set the property just like you would any other.  Setting this style as a ListBox's ItemContainerStyle worked fine for me.

    <Style TargetType="ListBoxItem" x:Key="ContainerStyle">
        <Setter Property="CacheMode" Value="BitmapCache"/>
    </Style>
    • Marked As Answer byJustTom Wednesday, November 04, 2009 8:35 AM
    • Unmarked As Answer byJustTom Wednesday, November 04, 2009 8:49 AM
    • Proposed As Answer byBrendan Clark - MSFT Wednesday, November 04, 2009 3:02 AM
    • Marked As Answer byJustTom Thursday, November 05, 2009 1:18 AM
    •  
     
  • Wednesday, November 04, 2009 8:04 PMBrendan Clark - MSFT Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     Answer
    Sign In to Vote
    0
    Sign In to Vote
    If you enable ClearType you'll also want to set SnapsToDevicePixels to true.  Snapping the cache to pixels should make everything less blurry, including the text.  The example XAML I gave you cheated a bit since we added a TypeConverter that creates a default-valued BitmapCache if you use the shorthand notation I used.  The verbose way that allows you to specify all the properties would look like this:

    <Style TargetType="ListBoxItem" x:Key="ContainerStyle">
        <Setter Property="CacheMode">
            <Setter.Value>
                <BitmapCache EnableClearType="True" SnapsToDevicePixels="True"/>
            </Setter.Value>
        </Setter>
    </Style>
     

All Replies

  • Wednesday, November 04, 2009 3:01 AMBrendan Clark - MSFT Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     Answer
    Sign In to Vote
    0
    Sign In to Vote
    I suppose I don't understand the problem here.  ListViewItem is a Control, which is a UIElement, so you should be able to set the property just like you would any other.  Setting this style as a ListBox's ItemContainerStyle worked fine for me.

    <Style TargetType="ListBoxItem" x:Key="ContainerStyle">
        <Setter Property="CacheMode" Value="BitmapCache"/>
    </Style>
    • Marked As Answer byJustTom Wednesday, November 04, 2009 8:35 AM
    • Unmarked As Answer byJustTom Wednesday, November 04, 2009 8:49 AM
    • Proposed As Answer byBrendan Clark - MSFT Wednesday, November 04, 2009 3:02 AM
    • Marked As Answer byJustTom Thursday, November 05, 2009 1:18 AM
    •  
     
  • Wednesday, November 04, 2009 8:35 AMJustTom Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     
    Sign In to Vote
    0
    Sign In to Vote
    THe problem is mostly one of me still getting my hands wet in WPF ;) I totally overlooked that - including the lttle fact that I even did have the style already defined in my XAML code ;) Nice ;)

    THe final part of the question then is - how do I set parameters in there?

    If I want to have

      <BitmapCache EnableClearType="True" RenderAtScale="1" SnapsToDevicePixels="False" />

    What would be the equivalent? I am particularly interested in EnableClearType - the text now is fast but looks blurry ;)
    • Marked As Answer byJustTom Thursday, November 05, 2009 1:11 AM
    • Unmarked As Answer byJustTom Thursday, November 05, 2009 1:11 AM
    •  
     
  • Wednesday, November 04, 2009 8:04 PMBrendan Clark - MSFT Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     Answer
    Sign In to Vote
    0
    Sign In to Vote
    If you enable ClearType you'll also want to set SnapsToDevicePixels to true.  Snapping the cache to pixels should make everything less blurry, including the text.  The example XAML I gave you cheated a bit since we added a TypeConverter that creates a default-valued BitmapCache if you use the shorthand notation I used.  The verbose way that allows you to specify all the properties would look like this:

    <Style TargetType="ListBoxItem" x:Key="ContainerStyle">
        <Setter Property="CacheMode">
            <Setter.Value>
                <BitmapCache EnableClearType="True" SnapsToDevicePixels="True"/>
            </Setter.Value>
        </Setter>
    </Style>
     
  • Thursday, November 05, 2009 1:11 AMJustTom Users MedalsUsers MedalsUsers MedalsUsers MedalsUsers Medals
     
    Sign In to Vote
    0
    Sign In to Vote
    Thanks ;) Will try ;) I still am stumbling like mad with the WPF delicacies ;)

    Funny how performance went up with caching (and text quality down) ;) Still not good enough, though ;) Will have to open another post with some concrete scenario.

    THanks for the help here ;) This Bitmap Caching is a great addition ;)