Vapolia.Svg 1.0.5

Samples for the Xamarin Svg enterprise cross platform and full featured Svg image control

This repository holds the samples for the XamSvg Xamarin control (Vapolia.Xamarin.Svg.Forms and Vapolia.Xamarin.Svg for UWP, Android and iOS).

Xamarin.Forms (Android, iOS, UWP)	Xamarin Native (Android, iOS, UWP)

Xamarin Forms controls:
SvgImageSource
SvgImage

Xamarin Android controls:
SvgImageView
SvgPictureDrawable

Xamarin iOS controls:
UISvgImageView

Native UWP controls:
Svg

More infos

Changes in the prerelease nuget

• Simplification: the "res:" prefix is now the default protocol and is not needed anymore.
• Simplification: Setting ResourceAssembly/ResourceAssemblies is now optional.

Coming soon (state: packing for release):

• ColorMapping and ColorMappingSelected can accept standard colors from styles.
• New features: interaction on the SVG including tap (or any other gesture) zone detection. Upcoming demo with zone highlightning and TappedZoneId event.

Quick start for Xamarin Forms

1. Add some svg files

Create a folder "images" at the root of your netstandard project (the project containing the App.cs file) and put your svg files there.
Make sure they have the .svg extension. And set their build action type to embedded resource (important!) in the file property window.

2. Use the SvgImage control

<?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:svg="clr-namespace:XamSvg.XamForms;assembly=XamSvg.XamForms"
             x:Class="XamSvg.Demo.MainPage">
  <ContentView>
    <StackLayout Orientation="Vertical" VerticalOptions="Start">

        <svg:SvgImage Source="logo.svg" HorizontalOptions="Start" HeighRequest="32" />

        <svg:SvgImage Source="logo.svg" HorizontalOptions="Start" HeighRequest="32"
                      ColorMapping="{Binding ColorMapping}" 
                      ColorMappingSelected="ffffff=00ff00;000000=0000FF" 
                      />
      
        <svg:SvgImage WidthRequest="100" Source="https://upload.wikimedia.org/wikipedia/commons/1/15/Svg.svg" />

        <svg:SvgImage WidthRequest="100" Source="data:image/svg+xml;base64,PD94bWwgdmVyc2lvbj0iMS4wIiBlb..." />
      
    </StackLayout>
  </ContentView>
</ContentPage>

Remarks:

• The xmlns:svg attribute is required on the ContentPage. If you use Resharper, it will be added automagically.
• The Source property value is the image name. It is searched in all embedded resources across loaded assemblies.
• All properties are bindable.

5. Enjoy

trick: You can also use <SvgImageSource Svg="...." Height="50" /> as the ImageSource for tab icons, button icons, navigation bar icons, ... But the Widht and/or Height is mandatory, as the Xamarin Forms controls infrastructure has a limitation: it has no way to dynamically give the target height to ImageSource objects.

Color Mapping

XamSvg supports remapping color based on a change in the control's state, like selected or disabled.

To specify a color mapping, set the ColorMapping, ColorMappingSelected or ColorMappingDisabled properties to a string. This string contains a list of mapping separated by a semicolumn ";". A mapping has two parts, separated by the equal sign. The left part is the color that should be replaced by the right part.

A color is specified using standard html coding: AARRGGBB, RRGGBB, or RGB. A is the transparency (alpha channel).

For example ffffff=00ff00;000000=0000FF means replace ffffff (white) by 00ff00 (green) and replace 000000 (black) by 0000FF (red).

Xamarin Forms samples

Simple svg image

   <svg:SvgImage Svg="res:images.logo" HeightRequest="70" HorizontalOptions="Center" VerticalOptions="Center" />

Svg image on a button

  <Button Text="Add Contact" ContentLayout="Right,20">
     <Button.ImageSource>
         <svg:SvgImageSource Svg="res:images.tabHome" Height="60" ColorMapping="000000=FF0000" />
     </Button.ImageSource>
  </Button>

Svg image for the icon of a TabbedPage tab

  <NavigationPage Title="Home">
    <x:Arguments>
        <views:HomePage />
    </x:Arguments>
    <NavigationPage.IconImageSource>
        <svg:SvgImageSource Svg="res:images.tabHome" Height="50" />
    </NavigationPage.IconImageSource>
  </NavigationPage>

Common mistakes

If nothing appears, make sure your svg is displayed correctly by the windows explorer (after you installed this extension).

Common errors include

• forgetting to set the build action of the svg file to "Embedded resource".
• missing viewBox attribute at the root of the svg file (open it using a text editor).
• the svg color is the same as the background color, especially white or black. Use ColorMapping to change colors, or edit your svg file with inkscape or your preferred text editor.

The assembly in which the svg resources are must have an assembly Name equal to its Default namespace, otherwise the svg files will not be found. If you are unable to do so, you can still display an svg but you will have to specify the full name of the resource like this:

    <xamForms:SvgImage
        Svg="res:YourDefaultNamespace.Images.getFDR_01_Ready.svg"
        x:Name="SvgIcon" HorizontalOptions="Fill" VerticalOptions="Start" Margin="8,0,8,0" BackgroundColor="Yellow"
        />

You can discover the full name of an embedded resource by opening your assembly (.dll in your bin folder) in the free tool Telerik JustDecompile.

Other Receipes

Icons on TabbedPage

<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:views="clr-namespace:XamSvg.Demo;assembly=XamSvg.Demo"
             xmlns:svg="clr-namespace:XamSvg.XamForms;assembly=XamSvg.XamForms"
             x:Class="XamSvg.Demo.Pages.TabContainer"
             Title="Vapolia.fr XamSvg Demo"
            >

  <views:HomePage Title="Home">
    <views:HomePage.IconImageSource>
        <svg:SvgImageSource Svg="res:images.tabHome" />
    </views:HomePage.IconImageSource>
  </views:HomePage>
    
</TabbedPage>

Mvvmcross

The library is fully compatible with mvvmcross bindings for all properties:
image source, color mappings, and all others.

Android native: make the svg image height the same height of a Button

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 
              xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              xmlns:tools="http://schemas.android.com/tools"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <Button
        android:id="@+id/myinfo"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="@string/Menu_MyInfo"
        style="@style/Widget.AppCompat.Button.Borderless"
        app:MvxBind="Click SettingsCommand"
        />
    <XamSvg.SvgImageView
        app:layout_constraintTop_toTopOf="@+id/myinfo"
        app:layout_constraintBottom_toBottomOf="@+id/myinfo"
        app:layout_constraintLeft_toLeftOf="parent"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        tools:layout_width="30dp"
        app:colorMapping="000000=e01a1a"
        app:colorMappingSelected="000000=ff3030"
        app:colorMappingDisabled="000000=1a1a1a"
        app:fillMode="fit"
        app:svg="res:images.info" />

Note that as the svg has an intrinsic width computed from its height and its aspect ratio, the width displayed by the designer is incorrect. You can correct the designer by assigning a design time only value to layout_width using the tools prefix: tools:layout_width="30dp" which requires the xmlns:tools namespace declaration.

Android native: set back button toolbar icon

var toolbar = FindViewById<Toolbar>(Resource.Id.toolbar);
toolbar.NavigationIcon = SvgFactory.GetDrawable("res:images.webbrowser.backward", "000000=FFFFFF");

Android: link all

This component is compatible with the "link all" linker option which reduces you app size by removing unused classes, properties and methods.
If you set the android linker to "link all", add these lines to the linker.xml file of your android application project:

  <assembly fullname="System.IdentityModel.Tokens.Jwt" preserve="all">
    <type fullname="System.IdentityModel.Tokens.JwtSecurityToken" preserve="all" />
  </assembly>
  <assembly fullname="Microsoft.IdentityModel.Tokens" preserve="all">
    <type fullname="Microsoft.IdentityModel.Tokens.JsonWebKey" preserve="all" />
  </assembly>

This is required because the xamarin tooling does not use linker.xml files from android libraries.

iOS storyboard: usage in an xcode storyboard

Using Visual Studio Mac, open your storyboard file using Open with xcode. Add an Image view (UIImageView), set its custcom Class property to UISvgImageView, and optionally add new User Defined Runtime Attributes as required:

To size your svg, set contraints on one dimension only. The other dimension will be set using the first dimension and the computed aspect ratio. If you set constraints on both dimensions, the svg will stretch. You can prevent this by setting FillMode to Fit (along with ContentMode to AspectFit):

When only one dimension is constrained, the designer don't know how to set the other dimension and displays contraint errors. The solution is to set the intrinsic size to a manual value in the dimension which has no contraint (in the dimension property pane of the designer).

1. Select the UISvgImageView view.
2. Show the size inspector (⌘Shift5).
3. Change the "Intrinsic Size" drop-down from "Default (System Defined)" to "Placeholder."
4. Enter reasonable guesses at your view's runtime width or height. Width if you set contraints on the height, height otherwise.

These constraints are removed at compile-time, meaning they will have no effect on your running app, and the layout engine will add constraints as appropriate at runtime to respect your view's intrinsicContentSize.

Reference

Xamarin Forms

Default namespace:

xmlns:svg="clr-namespace:XamSvg.XamForms;assembly=XamSvg.XamForms"

SvgImage control

SvgImage displays a image in up to 2 states: normal, selected

<svg:SvgImage Svg="res:images.union" HeightRequest="70" HorizontalOptions="Center" VerticalOptions="Center" />

SvgImageSource class

SvgImageSource inherits from ImageSource, use it on any ImageSource property. For example Page.IconImageSource. It can also be transformed into a FileImageSource by calling CreateFileImageSource().

SvgImageSource can be used in Button.ImageSource, ToolbarItem.IconImageSource, ...

<svg:SvgImageSource Svg="res:images.tabHome" Height="50" />

All properties are bindable, but Xamarin Forms does not support changing them after the control using this SvgImageSource is rendered. Alternatively, you can bind the ImageSource property on the target control, and define SvgImageSource in styles. Example:

    <svg:SvgImageSource x:Key="NormalIcon" Svg="res:resources.images.icon_normal" Height="80" />
    <svg:SvgImageSource x:Key="SelectedIcon" Svg="res:resources.images.icon_selected" Height="80" ColorMapping="FFF=000" />

    <Style x:Key="NormalIconStyle" TargetType="ImageButton">
      <Setter Property="Source" Value="{StaticResource NormalIcon}"/>
      <Setter Property="BackgroundColor" Value="Transparent"/>
    </Style>

    <Style x:Key="SelectedIconStyle" TargetType="ImageButton">
      <Setter Property="Source" Value="{StaticResource SelectedIcon}"/>
      <Setter Property="BackgroundColor" Value="Transparent"/>
   </Style>

And usage:

    <ImageButton Style="{Binding StyleKeyToUse}" />

     public string StyleKeyToUse {get;set;} = "NormalIconStyle"; 
     //Don't forget to call OnPropertyChanged(nameof(StyleKeyToUse)) after each change.

Android native

Layout properties:

android:padding is respected, and included in the width/height measurement.
android:gravity is respected, and included in the width/height measurement. If the svg is smaller than its view, this property controls its centering.

iOS native

UISvgImageView inherits UIImageView, so it's easy to use it in an xcode storyboard: drag an UIImageView and set its custom class to UISvgImageView. To set specific svg properties, add User Defined Runtime Attributes in the same pane where you set the custom class.

Attributes (supported in User Defined Runtime Attributes):

UIImageView.ContentMode is forced by UISvgImageView, so it has no impact. Use FillMode instead.

Advanced configuration

The svg files that don't specify the full path of an assembly are searched in the embedded resources of all loaded assemblies automatically. If you have late loading assemblies that are not detected, or if you prefer to manually specify the assemblies, add this line:

public class App : Application
{
    public App()
    {
        XamSvg.Shared.Config.ResourceAssembly = typeof(App).Assembly;
        ...
    }
...

Trick: you can add more than one assembly by using the ResourceAssemblies property instead.

More infos

More infos

Commercial support available.