I have run out of ideas for trying to change the DatePicker Format property in XAML using OnIdiom. I have tried using XAML styles, I have tried defining the string in a Constants.cs file and referencing it from XAML. The only other way I can think of would be to extended the DatePicker and set it in there. Has anyone gotten this to work?
Things that did not work are listed below.
Global Style with OnIdiom:
<Style TargetType="DatePicker">
<Setter Property="Format">
<OnIdiom x:TypeArguments="x:String"
Tablet="D"
Phone="d"/>
</Setter>
</Style>
Global style referencing a string defined in my Constants.cs class file, which uses Device.Idiom == TargetIdiom.Phone ? "d" : "D";
<Style TargetType="DatePicker">
<Setter Property="Format" Value="{x:Static map:Constants.LongDateTimeStringFormat}"/>
</Style>
Trying to only define the string with a key:
<OnIdiom x:Key="LongDateTimeStringFormat"
x:TypeArguments="x:String"
Tablet="D"
Phone="d"/>
Trying to only define the string with a key another way:
<x:String x:Key="LongDateTimeStringFormat">
<OnIdiom x:TypeArguments="x:String"
Tablet="D"
Phone="d"/>
</x:String>
It also does not work when trying to use <OnIdiom> within the <DatePicker.Format> directly, without styles, or trying to set the DatePicker.Format to {x:Static map:Constants.LongDateTimeStringFormat}.
Well... it seems to be working now in a different project. Adding the following global style does not give me a format exception like it did yesterday.
<Style TargetType="DatePicker">
<Setter Property="Format">
<OnIdiom x:TypeArguments="x:String"
Tablet="D"
Phone="d"/>
</Setter>
</Style>
May have to investigate a little later.
Related
I am trying to learn how to use Styles most effectively in WinUI 3 (from WindowsAppSDK 1.1.1) but I'm having difficulty getting simple inheritance to work.
Consider the NavigationViewItem class. I'd like to modify the default style to bind the FontSize and Height properties. The following works in my Page XAML:
<NavigationViewItem x:Uid="Shell_05" helpers:NavigationHelper.NavigateTo="ViewModels._05CreditViewModel"
FontSize="{Binding ViewModel.RootShellFontSize, ElementName=shellPage}"
Height="{Binding ViewModel.CurrentMenuItemHeight, ElementName=shellPage}">
<NavigationViewItem.Icon>
<BitmapIcon UriSource="\Images\credit.png"/>
</NavigationViewItem.Icon>
</NavigationViewItem>
But adding the two properties to a page resource does not (although the FontSize property works in each of the following. It's the Height that doesn't):
<Page.Resources>
<Style TargetType="NavigationViewItem" >
<Setter Property="FontSize" Value="{Binding ViewModel.RootShellFontSize, ElementName=shellPage}" />
<Setter Property="Height" Value="{Binding ViewModel.CurrentMenuItemHeight, ElementName=shellPage}" />
</Style>
</Page.Resources>
Neither does adding the style to a resource dictionary and merging. I've read over what I can find about inheriting styles and the BasedOn="" extension is an explicit way to derive from an existing style in WinUI versions prior to 2.6 (I think). Apparently, WinUI 3 does not require BasedOn. In any case, simply specifying TargetType="NavigationViewItem" doesn't work, but nor does
<Style TargetType="controls:NavigationViewItem" BasedOn="DefaultNavigationViewItemStyle">
The source code for v1.1.1 of the SDK declares a default style for the NavigationViewItem in generic.xaml, but there is no definition for DefaultNavigationViewItemStyle.
I also cannot derive from the default style using
<Style TargetType="controls:NavigationViewItem" BasedOn="{StaticResource {x:Type NavigationViewItem}}">
because x:Type is undefined.
I can do all of the bindings I want in code but I assume it's both clearer and more efficient to do it in XAML.
How do I inherit, derive from, or override a portion of the default style for a WinUI 3 control (not a custom control) in a desktop application, please?
Thanks for any help. Pointers to good XAML for WinUI 3 documentation (or books and articles) would also be greatly appreciated.
In your case the height is most probably not working since page.resources get compiled before object initialization and the height of the CurrentMenuItemHeight is 0. To solve it just set the mode to one way as such
{Binding ViewModel.CurrentMenuItemHeight,Mode=OneWay , ElementName=shellPage}
When you wish to use BasedOn, just say BasedOn={ThemeResource styleName}.
Just make sure the style is actually defined in Generic.xaml file which u can find in "C:\Users\AdminName.nuget\packages\microsoft.windowsappsdk\1.1.1\lib\uap10.0\Microsoft.UI\Themes"
So your final page.resources should be as such:
<Page.Resources>
<Style TargetType="NavigationViewItem" >
<Setter Property="FontSize" Value="{Binding ViewModel.RootShellFontSize, ElementName=shellPage}" />
<Setter Property="Height" Value="{Binding ViewModel.CurrentMenuItemHeight, Mode=OneWay, ElementName=shellPage}" />
</Style>
</Page.Resources>
But it would be much better to use x:Bind instead of Binding. You can view this page to learn more about it https://learn.microsoft.com/en-US/windows/uwp/data-binding/data-binding-in-depth
As an Android developer I'm used to work with #dimen/-constants in Androids XML. I find this future useful because it allows me to easily change multiple places that should have the same pixel-length together.
Does Xamarin.Forms have a similar features that I can use?
Well what you looking for are ResourceDictionaries
XAML resources are definitions of objects that can be shared and re-used throughout a Xamarin.Forms application.
These resource objects are stored in a resource dictionary.
A ResourceDictionary is a repository for resources that are used by a Xamarin.Forms application. Typical resources that are stored in a ResourceDictionary include styles, control templates, data templates, colours, and converters.
In XAML, resources that are stored in a ResourceDictionary can then be retrieved and applied to elements by using the StaticResource markup extension. In C#, resources can also be defined in a ResourceDictionary and then retrieved and applied to elements by using a string-based indexer. However, there's little advantage to using a ResourceDictionary in C#, as shared objects can simply be stored as fields or properties, and accessed directly without having to first retrieve them from a dictionary.
Creating and Consuming a ResourceDictionary
Resources are defined in a ResourceDictionary that is then set to one of the following Resources properties:
The Resources property of any class that derives from Application.
The Resources property of any class that derives from VisualElement
A Xamarin.Forms program contains only one class that derives from Application but often makes use of many classes that derive from VisualElement, including pages, layouts, and controls. Any of these objects can have its Resources property set to a ResourceDictionary. Choosing where to put a particular ResourceDictionary impact where the resources can be used:
Resources in a ResourceDictionary that is attached to a view such as Button or Label can only be applied to that particular object, so this is not very useful.
Resources in a ResourceDictionary attached to a layout such as StackLayout or Grid can be applied to the layout and all the children of that layout.
Resources in a ResourceDictionary defined at the page level can be applied to the page and to all its children.
Resources in a ResourceDictionary defined at the application level can be applied throughout the application.
The following XAML shows resources defined in an application level ResourceDictionary in the App.xaml file created as part of the standard Xamarin.Forms program:
<Application ...>
<Application.Resources>
<ResourceDictionary>
<Color x:Key="PageBackgroundColor">Yellow</Color>
<Color x:Key="HeadingTextColor">Black</Color>
<Color x:Key="NormalTextColor">Blue</Color>
<Style x:Key="LabelPageHeadingStyle" TargetType="Label">
<Setter Property="FontAttributes" Value="Bold" />
<Setter Property="HorizontalOptions" Value="Center" />
<Setter Property="TextColor" Value="{StaticResource HeadingTextColor}" />
</Style>
</ResourceDictionary>
</Application.Resources>
Beginning in Xamarin.Forms 3.0, the explicit ResourceDictionary tags are not required. The ResourceDictionary object is created automatically, and you can insert the resources directly between the Resources property-element tags:
<Application ...>
<Application.Resources>
<Color x:Key="PageBackgroundColor">Yellow</Color>
<Color x:Key="HeadingTextColor">Black</Color>
<Color x:Key="NormalTextColor">Blue</Color>
<Style x:Key="LabelPageHeadingStyle" TargetType="Label">
<Setter Property="FontAttributes" Value="Bold" />
<Setter Property="HorizontalOptions" Value="Center" />
<Setter Property="TextColor" Value="{StaticResource HeadingTextColor}" />
</Style>
</Application.Resources>
Each resource has a key that is specified using the x:Key attribute, which becomes it dictionary key in the ResourceDictionary. The key is used to retrieve a resource from the ResourceDictionary by the StaticResource markup extension, as demonstrated in the following XAML code example that shows additional resources defined within the StackLayout:
<StackLayout Margin="0,20,0,0">
<StackLayout.Resources>
<ResourceDictionary>
<Style x:Key="LabelNormalStyle" TargetType="Label">
<Setter Property="TextColor" Value="{StaticResource NormalTextColor}" />
</Style>
<Style x:Key="MediumBoldText" TargetType="Button">
<Setter Property="FontSize" Value="Medium" />
<Setter Property="FontAttributes" Value="Bold" />
</Style>
</ResourceDictionary>
</StackLayout.Resources>
<Label Text="ResourceDictionary Demo" Style="{StaticResource LabelPageHeadingStyle}" />
<Label Text="This app demonstrates consuming resources that have been defined in resource dictionaries."
Margin="10,20,10,0"
Style="{StaticResource LabelNormalStyle}" />
<Button Text="Navigate"
Clicked="OnNavigateButtonClicked"
TextColor="{StaticResource NormalTextColor}"
Margin="0,20,0,0"
HorizontalOptions="Center"
Style="{StaticResource MediumBoldText}" />
</StackLayout>
For more detailed information kindly take a look here
Apart from the StaticResource as mentioned above, 2 other ways to do it.
First one is, Having static class for constants and refer them in the XAML.
public static class GlobalSetting
{
public static double ImageRotation { get { return 180; } }
}
In the Xaml, you need to add this namespace in the page directive,
xmlns:gb="clr-namespace:XXXX.StaticData"
and use the constant in the xaml code as below,
<Image Source="icon_back.png" Rotation="{x:Static gb:GlobalSetting.BackImageRotation}" HeightRequest="24" </Image>
Second approach is, having a constant parameter in the BaseViewModel, and binding them in the Xaml code.
Sounds to me like you want to define constants/styles in a ResourceDictionary:
https://learn.microsoft.com/en-us/xamarin/xamarin-forms/xaml/resource-dictionaries.
In the ResourceDictionary you can define your constants/styles by key, in your XAML you can then refer to them as follows:
Color={StaticResource MyColorFromDictionary}
I'm making a ResourceDictionary of common styles that are used throughout my application and one of them is:
<Style x:Key="ME_BASE_AppbarButtonSaveStyle"
TargetType="AppBarButton">
<Setter Property="Label"
Value="Save" />
<Setter Property="ToolTipService.ToolTip"
Value="Save" />
<Setter Property="Icon">
<Setter.Value>
<FontIcon FontFamily="Segoe MDL2 Assets"
Glyph="" />
</Setter.Value>
</Setter>
</Style>
It's all ok if I apply the style only one AppbarButton on the Page, but if I want to have two buttons with the same style, I get the following error:
The parameter is incorrect
It's of ok (no error) if I remove the icon property out of the style...
But that's kind of missing the point...
Anyone experienced something similar? Perhaps...
Thank you for all the help.
Error HRESULT E_Fail has been returned from a call to a COM component.
This error will occurred when you use this style for the second AppBarButton. This error usually happens when a reference to a style or an event handler that does not exist or is not with the context of the XAML, you can see the exception information of your problem:
If you read this document: XAML resources must be shareable, you will find:
Custom types used as resources can't have the UIElement class in their inheritance, because a UIElement can never be shareable (it's always intended to represent exactly one UI element that exists at one position in the object graph of your runtime app).
Whether a Icon property of AppBarButton or a FontIcon derives from UIElement, so I guess this is the reason why can't this property be styled in the resource dictionary.
Besides, I will consider if this is a right direction to define the Icon property for each AppBarButton in the style, normally I'd like give each button a different icon as content.
But if you insist to do this, I can provide you a workaround method by defining the Content of the AppBarButton, this is the construction of your AppBarButton:
You use a FontIcon as the content of the AppBarButton, so we can modify your style like this:
<Style x:Key="ME_BASE_AppbarButtonSaveStyle" TargetType="AppBarButton">
<Setter Property="Label" Value="Save" />
<Setter Property="ToolTipService.ToolTip" Value="Save" />
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<FontIcon FontFamily="Segoe MDL2 Assets"
Glyph="" />
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
In WPF, if you want to base a style on the default style of a control, you would say:
<Style TargetType="customControls:ResponsiveGridView" BasedOn="{StaticResource {x:Type GridView}}">
However, x:Type is not supported on UAP - how do I do it then? I tried the following - none works (after defining XAML as an alias for the namespace where GridView is).
<Style TargetType="customControls:ResponsiveGridView" BasedOn="{StaticResource xaml:GridView}">
<Style TargetType="customControls:ResponsiveGridView" BasedOn="xaml:GridView">
None of this works - crashes on parsing the XAML.
Any more ideas?
You can still use "BasedOn" for inheritance of styles.
<Page.Resources>
<Style TargetType="Button" x:Key="MyOtherStyle">
<Setter Property="Background" Value="Red"></Setter>
</Style>
<Style TargetType="Button" BasedOn="{StaticResource MyOtherStyle}" >
<Setter Value="Green" Property="Foreground"></Setter>
</Style>
</Page.Resources>
Just define the resources like above. They'll be applied for every button on the page.
<Button Content="Hello"></Button>
To base on a default style of a control, you don't use "BasedOn". You implicitly base on the default style of a control by specifying the TargetType in the style.
To be more precise for your special case:
If you want to use an (implicit) style for your custom control that is based on a default style of a built-in control do the follwing:
Create a custom style that targets the built-in control type. Like this:
<Page.Resources>
<Style TargetType="Grid" x:Key="MyStyle1" >
<Setter Property="Background" Value="Green"></Setter>
</Style>
...
Then add another style that targets your custom control type an is based on your custom style for the built-in control. Like this:
...
<Style TargetType="local:MyCustomGrid" BasedOn="{StaticResource MyStyle1}">
<Setter Property="BorderBrush" Value="Black"></Setter>
<Setter Property="BorderThickness" Value="4"></Setter>
</Style>
</Page.Resources>
All your MyCustomGrid controls will implicitly get the style which is based on the default style.
All standard Grids will keep their default style, because they won't get the style implicitly, because you specified the x:key in the first style and therefore have to explicitly set the style of the grids. Does this clarify?
In my Windows Phone 8 app, I have some implicit styles defined in a xaml file at the location /Styles/DefaultStyles.xaml
I have a similar file but with different colors, fonts, etc ... defined at /Styles/GreenStyles.xaml.
I reference the default style file in my App.xaml as follows :
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Styles/DefaultStyles.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
I want to make my app switch its implicit styles from the other styles file (GreenStyles) programmatically.
How can I achieve this ?
**
UPDATE:
I manged to change the source of the resource dictionary as follows:
ResourceDictionary style = App.Current.Resources.MergedDictionaries.ToList()[0];
string source = String.Format("/ApplicationName;component/Styles/GreenStyles.xaml");
style.Source = new Uri(source, UriKind.Relative);
Note: the word component must be written like that to avoid exceptions
Now I have an issue:
only the Implicit styles (the ones that do not have a x:Key attribute) are switched when the source of the dictionary changes.
any other style with a specified key and defined twice (with different attributes) in both files, will not be reflected in the UI.
so if I have these files:
DefaultStyles.xaml:
<Style x:Key="MainGrid" TargetType="Grid">
<Setter Property="Background" Value="Red"/>
</Style>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="Red"/>
<Setter Property="FontSize" Value="24"/>
</Style>
</ResourceDictionary>
And:
GreenStyles.xaml:
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone">
<Style x:Key="MainGrid" TargetType="Grid">
<Setter Property="Background" Value="Green"/>
</Style>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="Green"/>
<Setter Property="FontSize" Value="24"/>
</Style>
</ResourceDictionary>
and I switched the source to point to GreenStyles.xaml, any Grid with the style MainGrid will still have it's background to Red.
What can be the reason for this ?
You can try using the approach Jeff Wilcox described here: http://www.jeff.wilcox.name/2012/01/phonethememanager/
Alternative approach is described here for Silverlight and I'm not sure if this will work on Windows Phone (though they share some codebase):
http://silverlightips.wordpress.com/2010/04/29/change-themestyle-using-merged-dictionaries/
Both of the ways are not easy if you have a large app and you may consider another option like (call me crazy)
<Button Style="{Binding Locator.Theme, Converter={StaticResource StyleThemeConverter}, ConverterParameter=RefreshButtonStyle}"
Hope this helps.