The general-purpose one. Where the other helpers belong to a single control, ControlsHelper is read by the templates of ButtonBase, CheckBox, ColorPalette, ComboBox, ContentControl, DatePicker, DropDownButton, NumericUpDown, PasswordBox, RadioButton, SplitButton, TextBox, Tile and WindowCommands.
| Property | Type | Default | |
|---|---|---|---|
CornerRadius |
CornerRadius |
0 |
rounds the control's border |
FocusBorderBrush |
Brush |
transparent | border while the control has keyboard focus |
FocusBorderThickness |
Thickness |
0 |
its thickness, where the template uses one. Obsolete on develop, see below |
MouseOverBorderBrush |
Brush |
transparent | border while the pointer is over the control |
BottomBorderBrush |
Brush |
unset | the bottom edge of the border, where a style draws that one stronger. On develop |
ContentCharacterCasing |
CharacterCasing |
Normal |
converts the content to upper or lower case |
DisabledVisualElementVisibility |
Visibility |
Visible |
the overlay drawn over a disabled control |
RecognizesAccessKey |
bool |
true |
whether an underscore in the content marks an access key |
IsReadOnly |
bool |
false |
makes the content of a control not editable |
FocusBorderThickness is obsolete on develop, and no template reads it any more. Swapping the border thickness on focus made the control jump, because its content had to move along with the thicker border, and a style built on top of that had no way to keep the layout still. Focus now colours the border the control already has, through FocusBorderBrush, and nothing moves. Setting the property still compiles and still does nothing to the built-in styles.
<TextBox mah:ControlsHelper.CornerRadius="4"
mah:ControlsHelper.FocusBorderBrush="{DynamicResource MahApps.Brushes.Accent}" />
The two defaults worth knowing
Buttons already upper-case their content. The helper's own default is Normal, but the MahApps button style sets ContentCharacterCasing to Upper, so the interesting direction is turning it off again:
<Button mah:ControlsHelper.ContentCharacterCasing="Normal" Content="Save" />
The border brushes default to transparent, and the styles fill them in. The MahApps text box style sets FocusBorderBrush to MahApps.Brushes.TextBox.Border.Focus and MouseOverBorderBrush to MahApps.Brushes.TextBox.Border.MouseOver. Reading the raw default is therefore misleading — what a styled control actually shows is whatever its style set.
BottomBorderBrush is what the WinUI look draws along the bottom edge. That edge is a border of its own in the template, carrying nothing but the line, so it follows the corners of the frame behind it and stays two units whatever the control is high. The WinUI text box, password box, rich text box and pickers set it; every other set leaves it unset and draws nothing there. On those styles FocusBorderBrush colours that edge rather than the whole frame, which is how WinUI marks the caret.
DisabledVisualElementVisibility set to Collapsed removes the wash that MahApps draws over a disabled control, which is worth doing when the control is inside something already dimmed.