[UWP]Plugins PictureChooser PluginLoader can`t load

[farlop]

Some time ago an UWP PictureChooser issue was asked to be created in this repository for follow up, but I've found no further reference in here

MvvmCross/MvvmCross#1258

Today I was trying with version 4.4 and same error happened to me

[Cheesebaron]

You need to add bootstrap file for it manually.

[farlop]

I've already done that. After adding the bootstrap file:

using MvvmCross.Platform.Plugins;

namespace XamarinFormsCross2.UWP.Bootstrap
{
    public class PictureChooserPluginBootstrap
        : MvxPluginBootstrapAction<MvvmCross.Plugins.PictureChooser.PluginLoader>
    { }
}

On launching I've got an MvxException at setup.Initialize() with message: could not load plugin assembly for type MvvmCross.Plugins.PictureChooser.PluginLoader.

I've checked that project has reference to MvvmCross.Plugin.PictureChooser assembly and that on bin\x64\Debug the MvvmCross.Plugins.PictureChooser.dll and MvvmCross.Plugins.PictureChooer.WindowsStore.dll are present.

[Cheesebaron]

I see the problem it looks for WindowsUWP and WindowsCommon, but it is the WindowsStore dll that is added to the project.

[farlop]

I supposed that, but I haven't found any version of the dll for UWP in the package. Platform targets for the package does not include 'uap10.0', which is found in other plugins (SQLitePCL for example).

[Cheesebaron]

Let me see if I can cook it up for WindowsUWP, otherwise if you want to have a stab at it feel welcome to do so.

[eshy]

The plugin has a WindowsStore dll which I think works fine in UWP projects if you override CreatePluginManager and add the .WindowsStore dll postfix. Is there a reason not to always search for WindowsStore if WindowsUWP or WindowsCommon don't exist?

[Cheesebaron]

I don't think it is correct to always dump win8.1 into UWP projects? What happens if you run that on a phone? Wouldn't it expect wpa8.1 in that case?

[eshy]

I guess so, I haven't actually tried it...

[Cheesebaron]

https://github.com/MvvmCross/MvvmCross-Plugins/tree/picturechooser_uwp

I've added an UWP implementation. It is just linking in the Store version as the API seems to be the same.

I don't have a Windows Phone around so can't test on that.

[Cheesebaron]

You can try this nuget locally and see if it works for you.

MvvmCross.Plugin.PictureChooser.4.4.1.nupkg.zip

[farlop]

I've tried on my W10M and now it doesn't throw any exception, the camera launches and the picture is taken and confirmed! But when I want to bind it to a Image control in the View it looks awkward. Please find it in the attached file.

The code used is this (Xamarin Forms):

MvxCommand _photo2Command;
        public ICommand Photo2Command
        {
            get


            {
                return _photo2Command ?? (_photo2Command = new MvxCommand(async () =>
                {
                    var task = Mvx.Resolve<IMvxPictureChooserTask>();
                    var photo = await task.TakePictureAsync(500, 90);

                    if (photo == null)
                        return;

                    Photo = ImageSource.FromStream(() => photo);

                }));
            }
        }

[Cheesebaron]

What is Photo and what is ImageSource?

I've only tried with a picture from the file picker which worked.

[farlop]

Photo is a Xamarin.Forms.ImageSource that I use for binding with the view. Let me show you the full relevant code for the ViewModel:

using MvvmCross.Core.ViewModels;
using MvvmCross.Platform;
using MvvmCross.Plugins.PictureChooser;
using Plugin.Media;
using Plugin.Media.Abstractions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;

namespace XamarinFormsCross2.Core.ViewModels
{
    public class SecondViewModel : BaseViewModel
    {
        string _message;
        public string Message { get { return _message; } set { SetProperty(ref _message, value); } }

        MvxCommand _photo2Command;
        public ICommand Photo2Command
        {
            get
            {
                return _photo2Command ?? (_photo2Command = new MvxCommand(async () =>
                {
                    var task = Mvx.Resolve<IMvxPictureChooserTask>();
                    var photo = await task.TakePictureAsync(500, 90);

                    if (photo == null)
                        return;

                    Photo = ImageSource.FromStream(() => photo);

                }));
            }
        }

        private ImageSource _photo;
        public ImageSource Photo { get { return _photo; } set { SetProperty(ref _photo, value); } }

        public SecondViewModel()
        {
            Message = "Segunda página!";
        }

        public void Init(string param)
        {
            if (param != null)
                Message = String.Format("{0} {1}", Message, param);
        }
    }
}

And this is the View:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="XamarinFormsCross2.Core.Views.SecondPage"
             Title="Segunda página">
    <StackLayout>
        <Label Text="{Binding Message}" HorizontalOptions="Center" />
        <Button Text="Foto 2" Command="{Binding Photo2Command}"></Button>
        <Image Source="{Binding Photo}" BackgroundColor="Gray"></Image>        
    </StackLayout>  
</ContentPage>

I'm using Xamarin.Forms + MVVMCross

[Cheesebaron]

Must be something wrong with the conversion of the stream to bitmap in Forms.

If I use the native Image view and the MvxInMemoryImageValueConverter it works just fine.

As you can see I captured a picture of my mug just fine.

private void DoPickPictureCommand()
{
    _pictureChooser.TakePicture(200, 100, (stream) =>
    {
        using (stream)
            ImageBytes = ReadFully(stream);
    }, () =>
    {

    });
}

private byte[] _imageBytes;

public byte[] ImageBytes
{
    get { return _imageBytes; }
    set
    {
        _imageBytes = value;
        RaisePropertyChanged(() => ImageBytes);
    }
}



public static byte[] ReadFully(Stream input)
{
    byte[] buffer = new byte[16 * 1024];
    using (MemoryStream ms = new MemoryStream())
    {
        int read;
        while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
        {
            ms.Write(buffer, 0, read);
        }
        return ms.ToArray();
    }
}

And View:

<Image Source="{Binding ImageBytes, Converter={StaticResource InMemoryImage}}" />

[farlop]

As I'm using Xamarin.Forms for sharing the views (and TBH I'm all new in this Xamarin world), I will keep using Xam.Plugin.Media which seems to work just fine with similar implementation.

Anyway, the issue with the UWP assembly seems to be solved, so thank you for your help!!