Could you tell me what is the main differences between Style and ControlTemplate ?
When or why to use one or the other ?
To my eyes, they are exactly the very same. As I am beginner I think that I am wrong, thus my question.
In a style you set properties of a control.
<Style x:Key="MyButtonStyle" TargetType="Button">
<Setter Property="Background" Value="Red"/>
</Style>
<Button Style="{StaticResource MyButtonStyle}"/>
All buttons that use this style will have their Backgrounds set to Red.
In a template you define the UI (structure) of the control.
<ControlTemplate x:Key="MyButtonTemplate" TargetType="Button">
<Grid>
<Rectangle Fill="Green"/>
<ContentPresenter/>
</Grid>
</ControlTemplate>
<Button Template="{StaticResource MyButtonTemplate}"/>
All buttons that use this template will have a green background that cannot be changed.
Values set in a template can only be replaced by replacing the entire template. Values in a style can be replaced by setting the value explicitly when using the control. That is why is better to use the properties of the control by using TemplateBinding instead of coding values.
<ControlTemplate x:Key="MyButtonTemplate" TargetType="Button">
<Grid>
<Rectangle Fill="{TemplateBinding Background}"/>
<ContentPresenter/>
</Grid>
</ControlTemplate>
Now the template uses the value of the Background property of the button it is applied to, so it can be customized:
<Button Template="{StaticResource MyButtonTemplate}" Background="Yellow"/>
Another useful feature is that controls can pick up a default style without having a specific style being assigned to them. You can't do that with a template.
Just remove the x:Key attribute of the style (again: you can't do this with templates). All buttons in the visual tree below the style will have this style applied.
Combining Templates and Styles is extra powerful: you can set the Template property in the style:
<Style TargetType="Button">
<Setter Property="Background" Value="Red"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<Rectangle Fill="{TemplateBinding Background}"/>
<ContentPresenter/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
No indeed you are quite wrong.
Styles set properties on controls. ControlTemplate is a property shared by most controls that specify how they are rendered.
To elaborate, you can use a style to group settings for a bunch of properties so you can re-use that to standardize your controls. Styles can be set explicitly on controls or applied too all of a certain type.
Control Templates can be set by a style or set explicitly on a control to change the way it appears. All controls have default templates (and styles for that matter) that are embedded in the .net wpf assemblies. It is quite enlightening to see these and understand how the wpf developers implemented the normal versions of all controls. If you have Expression blend installed, look in its "SystemThemes" folder.
UPDATE:
To understand how Styles and ControlTemplates can "add controls". In some way or another, the ControlTemplate is the only way to define the controls a control is made up of. But, some default .net controls allow you to use controls in place of text.
For example:
<GroupBox>
<GroupBox.Header>
<CheckBox/>
</GroupBox.Header>
</GroupBox>
This "adds" a checkbox to the groupbox without changing the ControlTemplate, but this is because the default ControlTemplate for GroupBox allows anything as the Header. This is done by using special controls such as ContentPresenter.
However, sometimes the default ControlTemplate for a control doesn't allow you to change something that you want to change via properties. Then you must change the ControlTemplate.
Whether you set the Properties of a control (Content, Header, ControlTemplate, IsEnabled, etc.) directly or via a style does not matter, Styles are only a convenience.
Hopefully this answers your question more clearly.
You can think of a Style as a convenient way to apply a set of property values to more than one element. You can change the default appearance by setting properties, such as FontSize and FontFamily, on each TextBlock element directly. However, if you want your TextBlock elements to share some properties, you can create a Style in the Resources section of your XAML file.
On the other hand, a ControlTemplate specifies the visual structure and visual behavior of a control. You can customize the appearance of a control by giving it a new ControlTemplate. When you create a ControlTemplate, you replace the appearance of an existing control without changing its functionality. For example, you can make the buttons in your application round instead of the default square shape, but the button will still raise the Click event.
Ref: http://msdn.microsoft.com/en-us/library/ms745683.aspx
I found some interesting differences in
The difference between styles and templates (msdn)
Style:
You can set only pre-existing properties in the style. For example, you cannot set a default value for a property that belongs to a new part that you added to the template.
Template:
When you modify a template, you have access to more parts of a control than when you modify a style. For example, you can change the way the pop-up list appears in a combo box, or you change the look of the button that triggers the pop-up list in the combo box by modifying the items template.
Style:
You can use styles to specify the default behavior of a control. For example, in a style for a button, you can specify a trigger so that when users move their mouse pointer over the button, the background color will change. These property changes are instantaneous (they cannot be animated gradually).
Template:
You can specify the behavior of any new and existing parts in a template by using triggers. For example, you can specify a trigger so that when users move their mouse pointer over a button, the color of one of the parts will change. These property changes can be instantaneous or animated gradually to produce a smooth transition.
OK, I had the exact same question and the answers I found in this thread pointed me in the right direction so I'm sharing, if only so I can understand it better myself.
A Style is more flexible than a ControlTemplate.
From Windows Presentation Foundation Unleashed, Adam Nathan and gang (writers) state this:
"Besides the convenience of combining a template [with a style using the Style's ControlTemplate setter] with arbitrary property settings, there are important advantages of doing this [setting the ControlTemplate setter on a style]:
It gives you the effect of default templates. For example, when a typed Style gets applied to elements by default, and that Style contains a custom control template, the control template gets applied without any explicitly markings on those elements.
It enables you to provide default yet overridable property valus that control the look of the template. In other words, it enables you to respect the templated parent's properties but still provide your own default values."
In other words, creating a style allows the user of the Style's Template setter to override the values set, even if they did not use a TemplateBinding ({TemplateBinding Width} for example). If you hardcoded the Width in your style, the user of the Style could still override it, but if you hardcoded that Width property in a Template, the user is stuck with it.
Also, (and this is kind of confusing) when using a ContentTemplate with a TemplateBinding the onus is on the user to set that property otherwise it will use the default property for the TargetType. If you use a style, you can override the default property of the TargetType by using a setter for the property and then applying a TemplateBinding referencing back to that setter. The book explains it better, page 338 (Mixing Templates with Styles)
Related
Is it possible to subclass a control (AppBarToggleButton in my case) and "inherit" TargetType of the base class? What I want to achieve is to have a slightly customized AppBarToggleButton (with disabled auto-toggle behavior) put into CommandBar and make it look exactly as if it was regular AppBarToggleButton (i.e. receive style whatever is defined for AppBarToggleButton inside given command bar control template). They say, DefaultStyleKey should help, but it is inherited fine, but, alas, doesn't seem to participate in local style resolution/lookup.
I may need to subclass other controls for various purposes, so the ultimate goal here is to understand how local style resolution works internally and does target instance has any involvement in it or is it a completely external process.
In general, we need make Templated Control for custom AppBarToggleButton. When we make Templated Control with Visual Studio, it will generate Generic.xaml file in the Themes folder that used to declare the custom control's style. And the the custom control cs file like the following.
public sealed class CustomAppBarToggleButton : AppBarToggleButton
{
public CustomAppBarToggleButton()
{
this.DefaultStyleKey = typeof(CustomAppBarToggleButton);
}
}
If you don't want to edit the default style you could remove DefaultStyleKey line that used to binding current control with the style in the Generic.xaml file.
Open Generic.xaml file you will find the following. And it's empty style. If we want to do some small changes, you need copy the complete AppBarToggleButton style to replace it and edit the TargetType to local:CustomAppBarToggleButton. Then you can edit the style base on your requirement.
<Style TargetType="local:CustomAppBarToggleButton" >
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:CustomAppBarToggleButton">
<Border
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}">
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
And if your want to make a new dependency property, please define it in the cs file then use TemplateBinding to bind the property in the style. For more please check this document.
For anyone still stumbling upon this. I managed to solve a similar issue, inheriting from Button, using the approach described here https://stackoverflow.com/a/71338869/10468107
Specifically, adding
<Style BasedOn="{StaticResource DefaultButtonStyle}" TargetType="local:MyButton" />
solved it for me. So maybe it works for other types as well, using {StaticResource Default<TYPE>Style}
I have a similar need and am wondering if the answer is still the same. I have extended the basic ComboBox control to meet some behavioral requirements.
class ExtendedComboBox : ComboBox
I want the ExtendedComboBox instances to inherit the latest platform styling but they are instead getting styled differently. The first of these is an ExtendedComboBox (square corners, larger glyph), while the second is a generic ComboBox (rounded corners, smaller glyph).
The requirement is to have the two combo boxes styled the same way. I am reluctant to create an explicit Style for ExtendedComboBox because then if the style for the generic ComboBox changes the ExtendedComboBox will no longer match. Is there some way to just inherit the standard style?
In WPF, if I apply a GridView to a ListView, then it will automatically change the Template property of the ListViewItem to a ControlTemplate that uses a GridViewRowPresenter instead of a ContentPresenter. This is usually what you want.
As it happens, though, I have a case where I want to keep the original ContentPresenter, so that it will render the ItemTemplate of the ListView.
(For the curious: I'm doing a parent-child thing where the columns are actually for the child elements, so while I do still have a GridViewRowPresenter, it's inside another list control inside the ItemTemplate of the ListView.)
I can do this by setting an ItemContainerStyle on the ListView, and setting the Template property in that to a custom ControlTemplate, since this will override the style setter that the GridView applies.
However this gets really wordy (especially to keep the selection colours) and it breaks the natural theme support, unless I make duplicate copies of the template for each theme, which is definitely silly.
What I really want to do is to write this:
<Setter Property="Template"
Value="{StaticResource {FindDefaultControlTemplate ListViewItem}}" />
Where the latter bypasses the ControlTemplate set by the GridView and obtains the ControlTemplate that a normal ListViewItem would have used.
Alternatively, if there's some way to tell a GridView to not alter the ListViewItem style at all, that would also work for my scenario.
This has to work inside XAML.
It appears that the magic incantation is to set this style:
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem"
BasedOn="{StaticResource {x:Type ListBoxItem}}" />
</ListView.ItemContainerStyle>
Apparently ListViewItem itself doesn't have a default style, but ListBoxItem does.
And this does override whatever GridView does and makes it use a plain ContentPresenter again.
So, I have this Window. On it, I'm creating a list of TextBlocks and TextBoxes in pairs. When you click on either, they will put a number in the corresponding TextBox, and set some values in the background. This all works well now.
I have the following XAML to create a custom Checkbox (as it has the behavior I'd like to use for this). My problem is that I want to bind different content into both the TextBlock and TextBox. For the TextBlock, I bound to the Content property, but I can't find a suitable option to satisfy the second binding. I considered placing it in the tag, but this didn't feel right, and in any case, I'm already binding an index value I require into there.
<Style x:Key="CustomCHK" TargetType="{x:Type CheckBox}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<DockPanel LastChildFill="True">
<TextBox DockPanel.Dock="Right" Width="50" Height="30" />
<TextBlock Text="{TemplateBinding Content}" TextWrapping="Wrap" />
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Feels like there should a simple solution to this, but I'm just trying to decide what's best. Do I create a custom checkbox class and just add a couple properties?
As always, I appreciate any direction you can offer me.
Unfortunately, there is no straightforward way to do this. I can see just two (somewhat flawed) workarounds:
Subclass CheckBox to suit your needs, and add the additional content properties that you need. The advantage is that this will fully enable your IDE's programming help for setting the content properties, and those properties will be typesafe. The downside is that your will need to add C# code for the sole purpose of declaring the additional content properties (i.e. without adding any "behavioral logic"), which somehow seems to conflict with a "clean" XAML-only for presentation approach.
You could try passing an array to the Content property, and then place several ContentPresenter instances in your control template, each of which bind to another item in the array. Binding property paths should support indexed access, though your code may become a bit verbose, as arrays in XAML have to be written explicitly by using the x:Array markup extension.
In WPF (VS2013), I'm creating a button like so:
<Button>
<Label>1</Label>
</Button>
Each of these buttons will have more to it, such as increased font size of the Label, grid row/column assignment, and I might use a binding for the label so that I can change the number. I'm creating a calculator app so I need to reuse this button 10 times (one for each number 0-9). Instead of copying/pasting this button XML 10 times, I wanted to see if I could templatize it.
I've read a little about ControlTemplate and DataTemplate, but I'm not sure if either of these are the correct thing to use. It's also not clear to me what should be a style or what should be a template.
So if someone could help me understand how to "templatize" the button and its styles (e.g. width, height, font size, etc) so that they can be easily reused, that would help a ton. Guidance is appreciated!
Use a ControlTemplate when you want to overwrite the entire template for a control, use a DataTemplate when you want to tell WPF how to draw a data object (usually the DataContext), and use ContentTemplate when you want to tell WPF how to draw the Content property of an object.
Creating a whole new ControlTemplate is quite complex. To demonstrate, check out this MSDN example for an example ControlTemplate for a Button.
In your case, I would recommend creating a Style for your button with setters for common properties such as Height, Width, Font, etc. If you want to draw your button's Content property in a custom way without completely overwriting the button template, include a ContentTemplate style setter to tell WPF how to draw the Button.Content property.
<Button Style="{StaticResource CalculatorButton}" Content="1" />
and
<Style x:Key="CalculatorButton" TargetType="{x:Type Button}">
<Setter Property="Height" Value="50"/>
<Setter Property="Width" Value="50"/>
<Setter Property="FontSize" Value="14" />
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock Text="{Binding }" FontFamily="Wingdings 3" FontWeight="Bold" FontSize="18" Foreground="Navy" />
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
The ControlTemplate defines how the button looks, the ContentTemplate defines how the Button.Content looks, and the DataTemplate used for the ContentTemplate is defining how the data object of "1" will be drawn.
You can start with a copy of the style of the button. Use Blend (part of VS) to create that: open the context menu of the button inside the object tree, then select "Edit template" (or similar, don't have an english version at hand), then "Copy of template" (or alike).
Now you may change properties (in designer or XAML). Every button that shall have this style needs to reference this new ressource.
You need to create a new Style of a button. Learning curve is not too steep, but the benefits are enormous. You can start learning about it here: http://msdn.microsoft.com/en-us/library/ms745683(v=vs.110).aspx
Long story short: Open your project with Blend, right-click on your button, "Edit Style", "Edit a copy". If you choose to define it in Application, you can reuse it among other pages (it will be then in you App.xaml file)
Once you have the base style, edit it as much as you need.
Is there a way to change the style of checkboxes when the ItemsOptionListType="CheckList"
inside a RadTreeView?
There are a couple of ways of doing this that I can think of, but sadly neither of them is particularly easy.
One way is to use Blend or a similar tool to obtain the template for the RadTreeViewItem class. The RadTreeViewItem class and its template are in the Telerik.Windows.Controls.Navigation assembly. Take a copy of this template and modify the CheckBox within this template to customise its appearance as you wish.
To use the template, add a ControlTemplate and a Style to the <UserControl.Resources> element of a XAML page, as follows:
<UserControl.Resources>
<ControlTemplate x:Key="myRadTreeViewItemTemplate" TargetType="telerik:RadTreeViewItem">
<!-- modified template goes here... -->
</ControlTemplate>
<Style TargetType="telerik:RadTreeViewItem">
<Setter Property="Template" Value={StaticResource myRadTreeViewItemTemplate}" />
</Style>
</UserControl.Resources>
This should then apply the modified template to any RadTreeViews in the same XAML file.
Note that we have to use an implicit style (i.e. one without an x:Key), since there seems to be no other way to tell a RadTreeView to apply a given style to its child items.
Alternatively, you can modify a built-in theme. This approach could also change the styles of CheckBoxes used within other Telerik controls in your application, for example in a GridViewCheckBoxColumn within a RadGridView.
EDIT: if you want the template for the CheckBox as used in the RadTreeView by default,
you'll find it in Themes\Office\Black\System.Windows.Controls.xaml within the Telerik.Windows.Controls assembly. This assumes you're using the 'Office Black' theme; adjust the path of this file if you're using a different Telerik theme.