RTB now showing everyhting

Question

I have a wpf richtextbox associated with a flowDocument. Supposing to number lines in the flowdocument from 1..60 The richtextbox is not tall enough to show all numbers.

But that's fine since I can scroll through the mouse wheel. The problem is that this procedure doesn't scroll enough as you can see in the following picture:

You may see that here it merely gets to line 50 instead than to line 60. It's not a problem of overlapping with other elements.

Thank you in advance for any help. Patrick

---ADD--- Here's the xaml

    <Grid Name="grdReport_RTF" Visibility="Hidden">
        <RichTextBox x:Name="rtbReport_RTF" Margin="10"  BorderBrush="Gray" Background="White" Foreground="Black" IsEnabled="True" Padding="10" Style="{DynamicResource rtbStyleDocLocal}" />
    </Grid>

with

<Style x:Key="rtbStyleDocLocal" TargetType="{x:Type RichTextBox}">
        <Style.Resources>
            <Style x:Key="{x:Type FlowDocument}" TargetType="{x:Type FlowDocument}">
                <Setter Property="OverridesDefaultStyle" Value="true"/>
            </Style>
            <Style x:Key="{x:Type Hyperlink}" BasedOn="{StaticResource {x:Type Hyperlink}}" TargetType="{x:Type Hyperlink}">
                <Style.Triggers>
                    <Trigger Property="IsMouseOver" Value="true">
                        <Setter Property="Foreground" Value="Blue"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="true">
                        <Setter Property="Foreground" Value="Black"/>
                    </Trigger>
                </Style.Triggers>
            </Style>
        </Style.Resources>
        <Setter Property="MinWidth" Value="10"/>
        <Style.BasedOn>
            <StaticResource ResourceKey="{x:Type TextBoxBase}"/>
        </Style.BasedOn>
    </Style>

--ADD2---

I populate the flowdoc with

Application.Current.Dispatcher.Invoke(new Action(() => fdocRTB.Blocks.Clear()));
if (File.Exists(strCompleteFilename))
{
    using (var sr = new StreamReader(strCompleteFilename))
    {
        String line = sr.ReadToEnd();
        Application.Current.Dispatcher.Invoke((Action)(() => fdocRTB = AddLineToRtb(fdocRTB_Beretta, line, false, RTB_LINEHEIGHT, RTB_FONTSIZE)));
    }
}

and with that

    private FlowDocument AddLineToRtb(FlowDocument fdoc, string str, bool IsTitle, double lineHeight, double fontSize)
    {
        Paragraph par;
        var run = new Run(str);
        run.Foreground = Brushes.Black;
        if (!IsTitle)
            run.FontWeight = FontWeights.Normal;
        else
            run.FontWeight = FontWeights.Black;
        run.FontSize = fontSize;
        run.FontFamily = ffRtb;
        par = new Paragraph() { LineHeight = lineHeight, FontSize = fontSize };
        par.Inlines.Add(run);
        Application.Current.Dispatcher.Invoke((Action)(() => fdoc.Blocks.Add(par)));
        return fdoc;
    }

--Add 3-- Some more clues to the solution: if the read file contains numbers 1..60 by scrolling down to the max the effect is:

[![enter code here][3]][3]

instead if I add some more lines with letter a...z by scrolling down to the max the effect is:

so well beyond 60!!!! But not to z

Wait a minute, I just realized I forgot about the FlowDocument part. How are you populating the text? — 15ee8f99-57ff-4f92-890c-b56153, Sep 22 '16 at 14:23
From the add2 you can see that basically I just add all the file. You can see that something is wrong since it doesn't show all 60 line but up to half number 50. thanx — Patrick, Sep 22 '16 at 14:34
That's roughly what I'm doing, but I'm not setting any style properties on the Paragraphs or Runs. What happens if you comment out those lines and let it use the default formatting? — 15ee8f99-57ff-4f92-890c-b56153, Sep 22 '16 at 14:43
Have you confirmed that it's not stretching the RTB outside the visible area? Easiest way to check that is just set Height="200" on the RTB and see how the scrolling works. — 15ee8f99-57ff-4f92-890c-b56153, Sep 22 '16 at 14:49
In fact, in your screenshots, I think I see a 1px lighter gray border down the side, but not across the bottom -- that would suggest that the actual bottom of the control is out of sight. The effect will be easier to be sure of if you give it BorderBrush="Red" (just for testing!) — 15ee8f99-57ff-4f92-890c-b56153, Sep 22 '16 at 14:51
Yeeeeeaaaahh thanx a million. You deserve to be rewarded please post a solution man. — Patrick, Sep 22 '16 at 15:03
:-( yes so clumsy of me. But I have to say that program is much more complicated with several layes and dinamic adaptation. Anyhow so clumsy of me... — Patrick, Sep 22 '16 at 15:06
Getting layout to stretch/not stretch/whatever as desired is a real weak point of XAML in my view. Maybe I'm just clumsy myself, but it bites me a lot. — 15ee8f99-57ff-4f92-890c-b56153, Sep 22 '16 at 15:07

score 2 · Accepted Answer · answered Sep 22 '16 at 15:06

Have you confirmed that it's not stretching the RTB outside the visible area? Easiest way to check that is just set Height="200" on the RTB and see how the scrolling works.

In fact, in your screenshots, I think I do see a 1px lighter gray border down the side, but not across the bottom -- that would suggest that the actual bottom of the control has been pushed down out of sight. The effect will be easier to be sure of if you give it BorderBrush="Red", just for testing.

Default XAML DWIM (actually "do what I would mean, if I meant to do it wrong") layout is probably the most common cause of scrolling issues in WPF.

RTB now showing everyhting

1 Answers1