Text update slowing down app

Question

I have a Hebrew calendar app where each day is a UserControl. I have 6 labels in that control for the English date, the Hebrew date, Jewish holidays and some other user-defined data. When scrolling, the labels' content changes as the date value for the UserControl goes up or down a week. The scrolling is noticeably slower than Microsoft Outlook Calendar, and profiling reveals that the part taking the longest is updating the label contents, which is not handled by my code.

Is there some way I can make this go faster? MS Outlook seems to have a comparable number of text fields, and the scrolling is smooth.

score 3 · Accepted Answer · edited May 23 '17 at 12:26

TextBlocks were not noticeably faster than Labels, but Glyphs gave my calendar whiplash.

Replacing this

<TextBlock Padding="5"
           FontFamily="Narkisim"
           FontWeight="Bold"
           FontSize="20"
           Text="{Binding HebrewDate}"/>

with this

<Glyphs Name="HebrewDate"
        Margin="5"
        StyleSimulations="BoldSimulation"
        FontUri = "/Fonts/nrkis.ttf"
        FontRenderingEmSize = "20"
        UnicodeString = "5771 ןושח ה"
        Fill = "Black"/>

made scrolling super fast.

Some notes:

Glyphs do not support binding, so I had to give each one a name and update them in the code behind, like so:
```
HebrewDate.UnicodeString = zman.HebrewDate;
```
Glyphs don't have Layout functionality so Hebrew text was coming out backwards. I had to preprocess the Hebrew strings with a reversing function. Even after reversing, the Hebrew vowel points came out misaligned, so I retained Labels for those strings which use vowels.

Having been brought to tears a few years ago by MS Word's handling of Hebrew text (text direction arbitrarily reversing _within the same word_), I am knocked out by the **superb** management of text direction in the Visual Studio editor. Acknowledgement and thanks to MicroSoft for the improvement! — Michael Sandler, Aug 05 '11 at 13:47

score 1 · Answer 2 · answered Aug 02 '11 at 11:08

I can't be sure but it is possible that MS Outlook was coded in something faster than WPF, perhaps using DirectX to show the graphics rapidly.

Otherwise I might suggest toning down on the number of bindings updating at once, I would suggest using an additional thread to gradually update the labels as and when there are spare cycles instead of all at once, which might be causing your stuttering.

score 0 · Answer 3 · answered Aug 02 '11 at 12:30

To go along with the previous answer, I recommend the background worker. Utilize the background worker for your most time consuming operation that gets executed during the scroll.

http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

Text update slowing down app

3 Answers3

Linked