Bug 57417 - It can not preview a page with a custom font.
Summary: It can not preview a page with a custom font.
Alias: None
Product: Visual Studio Extensions
Classification: Xamarin
Component: Xamarin.Forms Previewer ()
Version: unspecified
Hardware: Macintosh Mac OS
: --- normal
Target Milestone: ---
Assignee: Bugzilla
: 57942 ()
Depends on:
Reported: 2017-06-12 23:25 UTC by Igor K.
Modified: 2018-03-07 09:38 UTC (History)
10 users (show)

Tags: bb ac vsmac vs
Is this bug a regression?: ---
Last known good build:

Exception in the previewer. (116.02 KB, image/png)
2017-06-12 23:25 UTC, Igor K.
Sample solution that reproduces the error (205.97 KB, application/x-zip-compressed)
2017-07-11 11:49 UTC, Henrik W.

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Description Igor K. 2017-06-12 23:25:06 UTC
Created attachment 22844 [details]
Exception in the previewer.


Visual Studio Community 2017
Forms Project Support version 7.0.1

Create a simple Xamarin.Forms (PCL) project.

Try to use a custom font from Google - https://fonts.google.com/specimen/Tangerine

<?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:PersonalIncome3" x:Class="PersonalIncome3.PersonalIncome3Page">

    <Label Text="Welcome to Xamarin Forms!" 
        VerticalOptions="Center" HorizontalOptions="Center" 

In the iOS previewer everything ok.
In the Android(!) previewer I see an error. And it can't render the page.

System.NullReferenceException was thrown. Object reference not set to an instance of an object.

at Xamarin.Forms.Platform.Android.FontExtensions.ToTypeface 
... Xamarin.Forms.Platform.Android\Renderers\FontExtensions.cs:64

at Xamarin.Forms.Platform.Android.LabelRenderer.UpdateFont()
... Xamarin.Forms.Platform.Android\Renderers\LabelRenderer.cs:137

When I am running it in the Android emulator then it shows the label and font normally.
Comment 1 Mark McLemore 2017-07-10 23:34:49 UTC
Thank you for taking the time to submit the bug. We tried to reproduce the issue you reported but were unable given the description. If you could please attach a reproduction to the bug by starting with a clean Xamarin.Forms project and adding just the code necessary to demonstrate the issue, we would very much appreciate it.
Comment 2 Henrik W. 2017-07-11 11:46:43 UTC
I also have the same problem. 
Here's a solution which produces the same problem. 
I added 2 pages to an out of the box Xamarin Forms PCL solution. The font has been added to both the iOS and the Android project.
When running in the emulator everything is dandy but the forms previewer for Android wont have it.

I didn't bother for any finesse: there are 2 pages: one using the iOS fontname and one using the droid fontname. The app goes to the droid version.

please help us!

Comment 3 Henrik W. 2017-07-11 11:49:22 UTC
Created attachment 23473 [details]
Sample solution that reproduces the error
Comment 4 Pierce Boggan [MSFT] 2017-07-11 14:37:47 UTC
Thanks so much for taking the time to submit this report! I can confirm using the latest Visual Studio 2017 Preview version 15.3 I am able to reproduce this issue. Marking this report as CONFIRMED.
Comment 5 Pierce Boggan [MSFT] 2017-07-11 15:32:05 UTC
*** Bug 57942 has been marked as a duplicate of this bug. ***