Accessing an element defined in a style's template in wpf? - wpf

I have a wpf TabControl which I added a ScrollViewer to. This is all wrapped into a style which is situated in a resource dictionary.
Now, on the window's xaml side, all I do is set
.
I would like to access the control viewer element, as defined in the style as follows:
<Style x:Key="MyTabStyle" TargetType="{x:Type TabControl}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TabControl}">
<ScrollViewer />
.......
How do I access the ScrollViewer which is so deeply nested in the hierarchy?

Give it a name (theScrollViewer for instance), and use the FindName method to access it :
ScrollViewer scrollViewer = theTabControl.Template.FindName("theScrollViewer") as ScrollViewer;

Related

WPF Set controltemplate for only first level

I have a style for tabcontrol :
<Style TargetType="{x:Type TabControl}" x:Key="CloseableTabControl">
<Style.Resources>
<Style TargetType="{x:Type TabItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TabItem}">
this have effect for all tabitem contained into tabcontrol, including item of child tabcontrol.
I want that only first level tabitems have applicated the style.
How I can accomplish this?
Since you haven't set value x:Key for the TabItem style, hence it gets applied to all TabItems found in the Visual Tree. In case you want the style to be applied to only specific TabItems you need to set the x:Key value -
<Style TargetType="{x:Type TabItem}"
x:Key="TabItemStyle">
And wherever you want the Style to be applied, you have to use StaticResource-
<TabItem Style="{StaticResource TabItemStyle}"/>

Creating a custom control extending Image

I have a custom control extending Image, and I will put some more data on top of that image. However, when I am trying to style the component, I am getting the error that my Custom Control do not have the property Template Error:
Cannot find the Style Property 'Template' on the type 'MyCustomImage'
How can I style my custom control if Image does not have a Template Property?
Thanks
Edit:
Xaml:
<Style TargetType="{x:Type FieldComponents:MyCustomImage}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type FieldComponents:MyCustomImage}">
</ControlTemplate>
</Setter.Value>
</Setter>
</style>
Image inherits directly from FrameworkElement, not from Control, so it does not have a Template property. If you want to be able to template your control, you can inherit from Control or UserControl and have your template include an Image.

WPF: Set style on immediate children only

In my application I have a tab control which has several tab items.
The problem is that I want to apply a style to these tab items, but to no other (nested) tab items.
I have tried setting the following style on the tab control, but this also effects all children:
<Style x:Key="tabControlStyle" TargetType="{x:Type TabControl}">
<Setter Property="TabItem.Template" Value="{StaticResource tabItemTemplate}" />
</Style>
By using the code above I get the following error: 'TabItem' ControlTemplate TargetType does not match templated type 'TabControl', as TabItem and TabControl have the same DependencyProperty "Template", and the code tries to set the TabItemTemplate as TabControl- Template.
Can anybody help me?
Use the ItemContainerStyle property to apply a style to the items of an items control:
<Style x:Key="tabControlStyle" TargetType="{x:Type TabControl}">
<Setter Property="ItemContainerStyle" Value="{x:StaticResource tabItemStyle}" />
</Style>

WPF Custom Control TemplateBinding

How do i define a TemplateBinding for my custom control?
a little somthing like this..... (btw, this xaml is WPF, not silverlight--which is slightly different)
<style TargetType="{x:Type Button}">
<Setter Property="Background" Value="Green">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid Background={TemplateBinding Background}
</ControlTemplate>
</Setter.Value>
</Setter>
</style>
now, once you apply this style to an object, whenever you set the background of that object, the template will use the Background property (this is a property on the button control) and will be defaulted to what you set in the style (in this case, green)
If you want to use a property that does not exsist on the object of your style, you have to derive your own control and add the property as either a DependencyProperty or use the INotifyPropertyChanged interface. Here is a decent explanation for you.
Need a bit more information on what you are trying to do. Setting up a TemplateBinding can be done with the following XAML:
{TemplateBinding YourProperty}
or
{Binding RelativeSource={RelativeSource TemplatedParent}, Path=YourProperty}

WPF global font size

I'm creating a WPF app and I would like to know the best way to be able to change the font size for every element in the ui. Do I create a resource dictionary and set Styles to set the font size for all the controls I use?
What is the best practice?
I'd do it this way:
<Window.Resources>
<Style TargetType="{x:Type Control}" x:Key="baseStyle">
<Setter Property="FontSize" Value="100" />
</Style>
<Style TargetType="{x:Type Button}" BasedOn="{StaticResource baseStyle}"></Style>
<Style TargetType="{x:Type Label}" BasedOn="{StaticResource baseStyle}"></Style>
<Style TargetType="{x:Type TextBox}" BasedOn="{StaticResource baseStyle}"></Style>
<Style TargetType="{x:Type ListView}" BasedOn="{StaticResource baseStyle}"></Style>
<!-- ComboBox, RadioButton, CheckBox, etc... -->
</Window.Resources>
That way, if I want to change ALL the controls, I'd just have to change the "baseStyle" style, the rest would just inherit from it. (That's what BasedOn property those, you can also extend the base style if you create other setters inside of the inherited style)
FontSizeProperty is inherited from Parent Control. So you just need to change FontSize of your main window.
If you don't need dynamic behaviour this should work:
Add a style for Window to your ResourceDictionary
<Style TargetType="{x:Type Window}">
<Setter Property="FontSize" Value="15" />
</Style>
Apply the style to your main form (will not be applied implicit because its a derived type)
Style = (Style)FindResource(typeof (Window));
<Window> has a property FontSize.
So you can set desired fontsize in element if you want to change the fontsize in all the elements within that window.
<Window FontSize="12">
</Window>
Another option is to define the FontFamily and FontSize as resources.
<FontFamily x:Key="BaseFontFamily">Calibri</FontFamily>
<sys:Double x:Key="BaseFontSize">12</sys:Double>
That way you can use them in your setters.
Application.Current.MainWindow.FontSize = _appBodyFontSize;
This way you can change the Font Size at run time also.
TextElement.FontSize is an inherit property, which means you can simply set the font size at root element, and all the children elements will use that size (as long as you don't change them manually)
For any styles in WPF, you should have a separate resource dictionary that contains the styles for your app.
If you want to have a single Font Size that's reused throughout the app then just create a style for that font size. You can either give it a unique name/key to use explicitly or you can set a targetType that will transcend throughout the app.
Explicit Key:
<Style
x:Key="MyFontSize"
TargetType="TextBlock">
<Setter
Property="FontSize"
Value="10" />
</Style>
<Control
Style="{StaticResource MyFontSize}" />
*Note this style can be used with controls that have contentPresenters
For all textblocks in the app:
<Style
TargetType="TextBlock">
<Setter
Property="FontSize"
Value="10" />
</Style>
<TextBlock
Text="This text will be size 10" />
If you need to programmatically change global FontSize, not statically (XAML), to be applied once for all your windows, you can do:
TextElement.FontSizeProperty.OverrideMetadata(
typeof(TextElement),
new FrameworkPropertyMetadata(16.0));
TextBlock.FontSizeProperty.OverrideMetadata(
typeof(TextBlock),
new FrameworkPropertyMetadata(16.0));
This values are applied to any TextBlock, Labels and almost any text in any windows, whereas it has not a explicit FontSize defined. But this does not affect for TextBox, you have to write a similar code for it or any other special controls.
To dynamically change the font size globally with ctrl-mousewheel:
XAML:
<Window Name="MainWindow" ... PreviewMouseWheel="MainWindow_PreviewMouseWheel">
code behind:
private void MainWindow_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
{
if ((Keyboard.Modifiers & ModifierKeys.Control) != 0)
{
if (e.Delta > 0)
++mainCtrl.FontSize;
if (e.Delta < 0 && mainCtrl.FontSize > 1)
--mainCtrl.FontSize;
}
}
Using Resources in XAML is the way to go. Although there are many great answers to this question, I would like to add my two cents to the SCOPE of the Resource.
For Global accessibility in all of the Windows and User Controls of the Project, you can have your resource in the App.xaml file
<Application.Resources>
<Style TargetType="{x:Type Control}" x:Key="GlobalFontSize">
<Setter Property="FontSize" Value="28"/>
</Style>
</Application.Resources>
For accessibility at a Window level, you can have your resource in your xaml file for Window
<Window.Resources>
<Style TargetType="{x:Type Control}" x:Key="GlobalFontSize">
<Setter Property="FontSize" Value="28"/>
</Style>
</Window.Resources>
You could even have it at a Control level, for example
<DockPanel.Resources>
<Style TargetType="{x:Type Control}" x:Key="GlobalFontSize">
<Setter Property="FontSize" Value="28"/>
</Style>
</DockPanel.Resources>
Let's have some BLACK MAGIC things:
Add a double resource into your Application resource
<Application.Resources>
<sys:Double xmlns:sys="clr-namespace:System;assembly=mscorlib" x:Key="GlobalFontSize">12</sys:Double>
</Application.Resources>
Add a static property in your App class
public static double GlobalFontSize
{
get => (double)Current.Resources["GlobalFontSize"];
set => Current.Resources["GlobalFontSize"] = value;
}
Use this resource any where you want by DynamicResource
FontSize="{DynamicResource GlobalFontSize}"
Access property App.GlobalFontSize in any way to change value, binding is okay!
App.GlobalFontSize = 20;
//Or
{Binding Path=(local:App.GlobalFontSize)}

Resources