I want to bind some fontawesome icons into my XAML via view model.
I have it as following
Models
public string Icon { get; set; }
ViewModel
new Models.Item {Icon="",},
XAML
<Label>
<Span Text="{Binding Icon}"FontFamily="Materiales" FontSize="22" />
</Label>
What do I need to change or add?
In C# strings the escape character for the icon code is \u. If the icon code is f000, the string in C# becomes:
"\uf000"
I made a demo about the fontFamily and used the steps below.
First, I import the Lobster-Regular.ttf file to the project
Second, I set the Build Action of file to EmbeddedResource then put the code below into the AssemblyInfo.cs
[assembly: ExportFont("Lobster-Regular.ttf", Alias = "Lobster")]
Third, I use the MVVM method to bind the data to the label like this:
<Label Text="{Binding Name}" FontFamily="Lobster-Regular"></Label>
Here is the view of the label:
Related
In my app there is a certain listview that I use over and over in my app, only with different elements in it. Therefore, I put everything inside a contentview and inflated it in my xaml like so:
<ContentPage Title="Newbies" BackgroundColor="#fafafa">
<views:CV_AllAdsRes />
</ContentPage>
The class looks like this:
public partial class CV_AllAdsRes : ContentView
{
public CV_AllAdsRes(int id)
{
InitializeComponent();
SetAds();
}
}
Now, this doenst work, because I am not using a "default constructor". If I remove the "int id" from the constructor, it works no problem. But I need to be able to inflate this content view with different parameters inside the xaml.
Am I understanding this concept wrong?
How can I inflate my content view and give it parameters via xaml?
Thank you
I solved it by using a second constructor next to the default one and giving it arguments from xaml like so:
<views:CV_AllAdsRes >
<x:Arguments >
<x:Int32>5</x:Int32>
</x:Arguments>
</views:CV_AllAdsRes>
this will give ID=5.
I am trying to set up a component with data binding. This is basically a seperate content view that would have a property Item of type Item and supports binding. The following is the definition for the binding:
public static readonly BindableProperty ItemProperty
= BindableProperty.Create(
nameof(Item), typeof(Item), typeof(ItemComponent), null,
defaultBindingMode: BindingMode.TwoWay,
propertyChanged: ItemPropertyChanged);
private readonly ItemComponentViewModel vm;
static void ItemPropertyChanged(BindableObject bindable, object oldValue, object newValue)
{
var view = (ItemComponent)bindable;
view.Item = (Item)newValue;
}
public Item Item
{
get => (Item)GetValue(ItemProperty);
set
{
SetValue(ItemProperty, value);
if (vm != null) vm.Data = value; // break point here
}
}
The item doesn't seem to get bound. The commented line had a breakpoint and doesn't break. The complete source code is here: https://github.com/neville-nazerane/xamarin-component-sample
The above code can be found in the ItemComponent class. This component is called in the MainPage class.
Update
Just to explain what I am trying to simulate and why:
Why do we use MVVM in pages? While we'll have better type safety and performance by using the behind code directly, when the page's logic gets bigger, it becomes cleaner to handle it with a view model and to have a view that is simply bound to it.
Why do we have components? So that we can reuse a UI we intend to use with some functionality. If this functionality becomes complex it might need a view model for the same reason explained above. Hence, if pages need view models, I don't see why components won't need them at some point too.
This being considered this does feel like a particle requirement without easy to find examples.
So after looking at your example it turns out it's a bit of a complicated problem. So if my explanation is not clear, please let me know.
Basically the problem lies in these 2 code pieces:
MainPage.xaml(line 14):
<local:ItemComponent Item="{Binding Demo}" />
ItemComponent.xaml.cs (line 43):
public ItemComponent()
{
InitializeComponent();
vm = new ItemComponentViewModel();
BindingContext = vm; //this breaks the functionality
}
The first part you tell it to bind to the Demo property, and as normal it looks for this property in it's BindingContext. However in the second part you override it's BindigContext and set it to a ItemComponentViewModel this ViewModel however does not have a property Demo so the {Binding Demo} does not work on this new BindingContext you've set.
Now a possible solution for your demo application would be to change MainPage.xaml to the following code:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:SampleApp"
x:Class="SampleApp.MainPage"
x:DataType="local:MainViewModel"
x:Name="MyDemoPage">
<StackLayout>
<Label Text="Manual:" />
<Label Text="{Binding Demo.Title}" />
<Label Text="Component: " />
<local:ItemComponent Item="{Binding Path=BindingContext.Demo, Source={x:Reference MyDemoPage}}" />
</StackLayout>
</ContentPage>
Basically we now place the Demo binding outside of the BindingContext of our ItemComponent control. However if you want to use it in a ListView (if I remember correctly from your original question, this solution might not work and it's possible you'll have to drop the ItemComponentViewModel and bind directly to the properties (ListView will already make sure that the BindingContext of your ItemComponent is set to the current Item, no need to pass it around through a bindable property.
Hope this helps!
I got a page in which I load multiple control template considering some business logic binded to a property in my viewModel.
<ContentView x:Name="ContentView" ControlTemplate="{Binding ItemControlTemplate}">
</ContentView>
Inside this control template I got a CarouselViewControl which uses a DataTemplate.
<carousel:CarouselViewControl x:Name="CarouselViewMapTemplate" Position="
{TemplateBinding BindingContext.CarouselPosition}"
PositionSelectedCommand="{TemplateBinding BindingContext.PositionChanged}"
Orientation="Horizontal" AnimateTransition="True" IsSwipeEnabled="False"
ItemsSource="{TemplateBinding BindingContext.Items}" InterPageSpacing="10"
ItemTemplate="{StaticResource ItemsDataTemplate }">
</carousel:CarouselViewControl>
And inside this DataTemplate I would like to bind to a property in the ViewModel, which is also a DataTemplate.
<maps:SfMaps x:Name="sfmap" EnablePanning="False" EnableZooming="False" BackgroundColor="Transparent">
<maps:SfMaps.Layers>
<maps:ShapeFileLayer x:Name="ShapeLayer" Uri="FRA_adm0.shp" MarkerTemplate="{Binding Parent.BindingContext.MarkerDataTemplate}">
</maps:ShapeFileLayer>
</maps:SfMaps.Layers>
</maps:SfMaps>
How can I achieve that ? I just tried
{Binding Parent.BindingContext.MyProperty}
but this is not working. I also digged with Source property of binding, but that won't do it as I don't have reference in my DataTemplate, used as resource in the app level ResourceDictionary.
This DOESNT work ofc it does not find carouselView in the ResourceDictionary :
"{Binding Path=BindingContext.DisplayMarkerTemplateCommand, Source={x:Reference carouselView}}"
Not being able to do that breaks the whole point of having ResourceDictionary and clean templating if binding is not working from it with XAML.
THANKS !
When putting together a TabbedPage in Xamarin.Forms, how do I get UWP to use the page's Icon property?
It looks like UWP could support this just fine, if I configure my Forms attributes/files correctly.
Here's my TabbedPage XAML. The icons are all set up and working for iOS and Android, and even the on-page Image in UWP renders fine (meaning the files are likely in the project correctly).
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:tabbed"
x:Class="tabbed.MainPage">
<TabbedPage.Children>
<local:InitialPage Title="Tab1" Icon="star.png" />
<ContentPage Title="Tab2" Icon="gear.png">
<ContentPage.Content>
<StackLayout>
<Label Text="A nice label." />
<Image Source="star.png" /><!-- works here -->
</StackLayout>
</ContentPage.Content>
</ContentPage>
</TabbedPage.Children>
</TabbedPage>
I outlined how this is possible here http://depblog.weblogs.us/2017/07/12/xamarin-forms-tabbed-page-uwp-with-images/
In short, you need to change the default HeaderTemplate that is being used by UWP. But due to the way Xamarin forms is started, this is not straightforward.
So you need to inject a custom template into the resource dictionary.
Example project is up on Github here https://github.com/Depechie/XamarinFormsTabbedPageUWPWithIcons
Longer detail:
You need to supply your own TabbedPageStyle and switch out the one that Xamarin is using for their UWP rendering.
So the new style contains an Image where we data bind the Source to the Xamarin Icon property.
<Style x:Key="TabbedPageStyle2" TargetType="uwp:FormsPivot">
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<StackPanel Orientation="Vertical">
<Image Source="{Binding Icon, Converter={StaticResource IconConverter}}" Width="15" Height="15" />
<TextBlock Name="TabbedPageHeaderTextBlock" Text="{Binding Title}"
Style="{ThemeResource BodyTextBlockStyle}" />
</StackPanel>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
The actual style switching is done in the App.Xaml.cs like this
((Style)this.Resources["TabbedPageStyle"]).Setters[0] = ((Style)this.Resources["TabbedPageStyle2"]).Setters[0];
You'll also need a converter to be sure the Image control understands the Icon source giving by Xamarin
public class IconConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, string language)
{
if (value != null && value is Xamarin.Forms.FileImageSource)
return ((Xamarin.Forms.FileImageSource)value).File;
return null;
}
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
throw new NotImplementedException();
}
}
As it is currently, the UWP TabbedPage renderer does not use the Icon property at all, so getting tab icons will require a custom renderer. Even the official UWP samples don't actually seem to have this baked-in, requiring a custom UserControl.
The Android TabbedPageRenderer and iOS TabbedRenderer, and even the macOS TabbedPageRenderer, use the Icon property to adjust the tab UI, but the UWP renderer would need updating to make this work.
I am trying a new approach i.e. XAML to make application in xamarin.forms. At this time i am facing an issue to reuse my stack layout which is having a image and label. How i can reuse my layout in different pages using XAML.
You can actually define your custom component in a separate XAML file and then just link the component wherever you need it.
For example a label with image can be grouped together in a dedicated XAML file:
<?xml version="1.0" encoding="utf-8" ?>
<StackLayout xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="UserControls.ImageWithTitle"
VerticalOptions="Center" HorizontalOptions="Center" >
<Label HorizontalOptions="Center"
x:Name="TitleLabel" />
<Image Source="noimage.png" />
</StackLayout>
On the .cs file I've defined a binding for the TitleLabel
public string TitleName
{
get { return TitleLabel.Text; }
set { TitleLabel.Text = value; }
}
So when you include the component on another layout, you can assign the label value directly (or via a binding):
<usercontrols:ImageWithTitle TitleName="Home"/>