I've set some properties in my App.xaml to implicitly style all of the ChildWindows in my app, but it doesn't seem to work.
I can set an implicit global style for any other type of control and it works, but when I set styles for ChildWindows, it literally changes nothing.
Here is an example of the XAML that doesn't work:
<Style TargetType="controls:ChildWindow">
<Setter Property="OverlayOpacity" Value="0" />
</Style>
Shouldn't this just work?
The problem is that impilict styles only apply to controls of the specific type referenced by the TargetType. They do not apply to derived types of the TargetType.
Since you will never be creating an instance of ChildWindow but will be creating only derived types of ChildWindow the style does not apply.
For such a small variation you might as well just include OverlayOpacity="0" in the Xaml of your child windows.
Related
My custom control's default style is defined in Generic.xaml and is working fine.
However, when I try to change the style of my custom control the same way as one can with built in controls nothing happens. In App.xaml I am trying to change the default style of my control by doing the following:
<Style TargetType="{x:Type my:CustomControl}">
<Setter Property="Background" Value="Red"/>
</Style>
If I set the x:key property of the above style and reference this style using this key all works fine.
Is it correct that the above styling method only works for built in controls and does not work for custom controls, or am I just doing something wrong? Is there a workable solution to achieve this type of styling for custom controls?
Update
In this situation my custom control is derived from System.Windows.Window.
I finally managed to get implicit styling for my custom control to work. Apparently implicit styling might not work for derived controls as the style is not automatically being applied to the control. In order to achieve this one has to manually set the resource reference. My custom control now looks like this:
public class CustomControl : Window
{
static CustomControl()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomControl), new FrameworkPropertyMetadata(typeof(CustomControl)));
}
public CustomControl()
{
SetResourceReference(StyleProperty, typeof(CustomControl));
}
}
Yes, you are correct. Generic.xaml is used for custom controls, and App.xaml for application-wide resources (including styles for built-in controls). Specifying TargetType for a custom control in App.xaml will not work. So using explicit styles (with x:Key) seems to be the easiest solution.
I'm creating the custom control. And suddenly faced a question: why to put control's style separately from the control?
I mean that using the standard way you must: derive from base control (for example, from TextBox) and add a style for it in general.xaml.
But why can't we do just like this:
<TextBox x:Class="CustomTest.CoolTextBox"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<TextBox.Style>
<Style>
<Setter Property="TextBox.FontSize" Value="20" />
</Style>
</TextBox.Style>
</TextBox>
And code-behind:
public partial class CoolTextBox : TextBox
{
public CoolTextBox()
{
InitializeComponent();
}
}
Update #1
I'm not writing my own library but creating a custom control inside my main executable. Application support themes but they differ only by colors. So each theme is a set of brush resources and my style will refer them using DynamicResource.
What I want to know is the drawbacks of that solution. I mean performance, simplicity of usage and etc.
WPF allows changing themes at runtime, means the style shall be stored separatly from the controls. Futhermore the control shall be lookless when designining in order to other programmers to have their custom styles though somewhere there should be a default style which must be stored separatly in a Generic.xaml file. If your app doesn't support changing themes then you can define the style wherever you wish.
If you are writing a library of custom controls I suggest you to stick to standards.
Here is a link how shall a custom controls be created:
http://wpftutorial.net/HowToCreateACustomControl.html
In addition to dev hedgehog's answer about performance, I found the following drawbacks:
Style object is own for each instance of control. So you end up with number of clones of the same Style object.
You cannot override style using BasedOn property. Only completely replace is possible.
In my case, based on configuration settings grid lines should appear in different colors.
I have defined a simple style with TargetType of CellValuePresenter and I noticed that the style is applied to all columns except the ones which also have a style with target type of CellValuePresenter and have their own ControlTemplate. And I have lots of styles with ControlTemplates for CellValuePresenter across the solution, and it is not possible to change all of them to be BasedOn this new style I created.
What are my options so that the styles with ControlTemplates pickup my changes without modifying each one of them.
(Un)fortunately, styles don't apply like they do in CSS, so there's no ambiguity of what you will end up with at the end, where styles build up on each other.
If you create a style for a type, it is applied across all types in the scope of your style. This means if you include it at the top in your app.xaml, everything is affected, but if you include it only for a user control or window.xaml, it only applies to that.
If you create a style and apply it on a specific control, the local style set will override the global type based one. Unless you use BasedOn, which you specifically say you cannot do.
Unfortunately, I think you will be forced to refactor how you handle your styles to get the look you are trying to achieve, and BasedOn will be the way to go.
You can make a style BasedOn the default style for that element so that it includes all setters from the implicit style as well.
For example,
<Style TargetType="{x:Type CellValuePresenter}">
<!-- Generic Style Setters -->
</Style>
<!-- This Style will include the setters from the implicit style above -->
<Style x:Key="CustomCellStyle"
TargetType="{x:Type CellValuePresenter}"
BasedOn="{StaticResource {x:Type CellValuePresenter}}">
<Setter Property="ControlTemplate" ... />
</Style>
I've create a style for ListItems that I want to use across all ListBoxes in my application. I can set these manually like so:
<ListBox ItemContainerStyle="">
But I'm having trouble getting the style to apply to every single ListBox in my application without touching each one and adding the above attribute.
In addition, and more importantly, I want to apply the style to list boxes used within custom templated controls. Right now I have to modify the Generic.xaml theme in the control library... not something i think I should have to do.
Fairly certain this has something to do with themes, btu having a heck of a time figuring it out.
You can do this with implicit styles in Silverlight 4.
Define your style in the regular way:
<Style x:Key="DefaultListBoxStyle" TargetType="ListBox">
....
<Style>
then create the implicit style:
<Style TargetType="ListBox"
BasedOn="{StaticResource DefaultListBoxStyle}" />
you could use implicit styles.
http://www.silverlightshow.net/items/Implicit-Styles-in-Silverlight-4.aspx
You define one global style for a type (in your case ListBoxItem) and then this style is the new default style for your app.
If you need any further information, just leave a comment.
BR,
TJ
I have created two different grid background and radio button style in my
App.xaml.
User can select any style to change the look of the page i.e: Changing the background and style of the radiobutton.
Now When I click on the raduio button the application navigates to another page and the style disappears.
Is there a way to Set the style in application level or I need to store the styleVar as Global Var and check on the second page load and then apply the styles as per the styleVar.
Yes like Jeff Wilcox said Implicit styling is a new thing in Silverlight 4. So if you want to create a style that is the default for all the controls of that type in the range XAML file or the whole application if placed in App.xaml you would leave out the x:Key attribute.
<Style x:Key="ButtonStyle" TargetType="Button">
To use ButtonStyle you would have to write:
<Button Content="A button" Style="{StaticResource ButtonStyle}" />
Leaving out the x:Key would allow you to use ButtonStyle as default.
<Style TargetType="Button">
<Button Content="A button with style that has no x:Key value" />
Now if you'd need to create a button that doesn't have this default style, you can set the Style property of that button to be x:Null or override by setting a named style to that button.
<Button Content="Default Silverlight button" Style="{x:Null}"/>
Another new thing with Styles in Silverlight 4 is that you can create new styles that are based on existing ones. Although it wasn't your question I'll give an example:
<Style TargetType="Button" BasedOn="{StaticResource BasedStyle}">
About implicit styling in the docs: http://msdn.microsoft.com/en-us/library/system.windows.style%28VS.95%29.aspx
Implicit Styles
In Silverlight 4, you can set styles
implicitly. That is, you can apply a
certain style to all elements of a
certain type. When a resource
is declared without an x:Key value,
the x:Key value assumes the value of
the TargetType property. If you set
the style implicitly, the style is
applied only to the types that match
the TargetType exactly and not to
elements derived from the TargetType
value. For example, if you create a
style implicitly for all the
ToggleButton controls in your
application, and your application has
ToggleButton and CheckBox controls
(CheckBox derives from ToggleButton),
the style is applied only to the
ToggleButton controls.
BasedOn Styles
Starting with Silverlight 3, it is
possible to build a new style based on
an existing style. You can do this
using the BasedOn property. This
reduces the duplication of code and
makes it easier to manage resources.
Each style supports only one BasedOn
style. For more information, see the
BasedOn property.
Just leave off the x:Key part of the Style, inside App.xaml. This is a new feature for Silverlight 4.
Place the styles in question in the App.xaml file. The application objects Resources property makes Styles and other resources available across the entire application.