Set size of DashedLine explicitly

[greuelpirat]

Resolves #1735

I found that this trigger caused the high CPU usage:

MaterialDesignInXamlToolkit/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.TextBox.xaml

Lines 278 to 285 in 71af777

	<MultiTrigger>
	<MultiTrigger.Conditions>
	<Condition Property="IsEnabled" Value="false" />
	<Condition Property="wpf:TextFieldAssist.HasOutlinedTextField" Value="False" />
	<Condition Property="wpf:TextFieldAssist.HasFilledTextField" Value="False" />
	</MultiTrigger.Conditions>
	<Setter TargetName="DashedLine" Property="Visibility" Value="Visible" />
	</MultiTrigger>

So I guess that the disabled DashedLine (disabled, because of placement in RightDrawerContent) had no fix size. So I set it:

MaterialDesignInXamlToolkit/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.TextBox.xaml

Lines 165 to 166 in 71af777

	Height="{Binding BorderThickness.Bottom, ElementName=border, Converter={StaticResource DivisionMathConverter}, ConverterParameter=0.75}"
	Width="{Binding ActualWidth, ElementName=border}"

and the CPU usage was gone.

Beside MaterialDesignTheme.TextBox.xaml I updated other controls, since they seems to have a similar DashedLine

• MaterialDesignTheme.ComboBox.xaml
• MaterialDesignTheme.DatePicker.xaml
• MaterialDesignTheme.PasswordBox.xaml
• MaterialDesignTheme.TimePicker.xaml

PS: I also updated the Fields.xaml in demo app, where I forgot the disabled fields during #1749 :-(

[Keboo]

Really great working tracking this down. Thank you

[Keboo]

Though this works, binding to BorderTickness.Bottom exposes a memory leak (the Binding leak section) because BorderThickeness is a just a Thickness struct. It actually appears that we have the same bug on the StrokeThickness as well. I would propose the following fixes:

1. Since it looks like we are trying to keep these properties in sync, why not simply bind the Height to the StrokeHeight property. {Binding StrokeHeight, RelativeSource={RelativeSource Self}}
2. Rather than binding through the BorderThickness property, lets create a value converter that takes in the BorderThickness directly, and applies the appropriate math we need for this line. I would propose that this converter be made internal for now.

[greuelpirat]

Good points. I have implemented those. 👍