Question

How can I make a richtextbox with a dotted border

I tried something like this:

    <Border Width="100" Height="100" Background="White" BorderThickness="1,1,1,1">
        <RichTextBox Name="richTextBox1" />
        <Border.BorderBrush>
            <LinearGradientBrush StartPoint="0,0" EndPoint="0,.1" SpreadMethod="Repeat" >
                <GradientStopCollection>
                    <GradientStop Color="Transparent" Offset="0" />
                    <GradientStop Color="Transparent" Offset="0.2" />
                    <GradientStop Color="Red" Offset="0.2" />
                    <GradientStop Color="Red" Offset="0.4" />

                    <GradientStop Color="Transparent" Offset="0.4" />
                    <GradientStop Color="Transparent" Offset="0.6" />
                    <GradientStop Color="Red" Offset="0.6" />
                    <GradientStop Color="Red" Offset="0.8" />
                    <GradientStop Color="Transparent" Offset="0.8" />
                    <GradientStop Color="Transparent" Offset="0.9" />
                    <GradientStop Color="Red" Offset="0.9" />
                    <GradientStop Color="Red" Offset="1" />


                </GradientStopCollection>
            </LinearGradientBrush>

        </Border.BorderBrush>
    </Border>

but that only works for left/right or top/bottom

Answer 1

(sorry for my bad english)

Try this:

<Grid Width="200" Height="80">
        <Rectangle Fill="Transparent" Stroke="Red" StrokeThickness="3"  StrokeDashArray="1 1"/>
        <RichTextBox BorderThickness="0" Margin="3"/>
</Grid>

Is a bit of a hack, maybe you can create a style with this so you can override the RichTextBox borders too.