title: How to include Java jar to C# Xamarin project (Picasso example), problem with ImageView android:src field
body: <p>I am doing a java to c# transition, and need help.
  in Visual Studio 2019 Pro, Android 9.0 (Pie), I am doing this example:</p>
  
  <p><a href="https://docs.microsoft.com/en-us/xamarin/android/platform/binding-java-library/binding-a-jar" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/xamarin/android/platform/binding-java-library/binding-a-jar</a></p>
  
  <p>The goal is later to convert my java libs to c# for my big project.</p>
  
  <p>I follow the instructions to the letter, and when I come to the part where I need to create an ImageView, there is the problem. Once I create the ImageView, it has an android:src field, something like this (auto generated):</p>
  
  <pre><code>android:src="@drawable/icon"
  </code></pre>
  
  <p>The problem here, is when I remove that field, in the VS designer, the ImageView disappears and it does not matter if I have the c# code or not, even when I set the srec to:""</p>
  
  <p>Bellow is literally all the code in <strong>MainActivity</strong>:</p>
  
  <pre><code>using Android.App;
  using Android.OS;
  using Android.Support.V7.App;
  using Android.Runtime;
  using Android.Widget;
  
  using Com.Squareup.Picasso;
  
  namespace App3
  {
      [Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = true)]
      public class MainActivity : AppCompatActivity
      {
          protected override void OnCreate(Bundle savedInstanceState)
          {
              base.OnCreate(savedInstanceState);
              Xamarin.Essentials.Platform.Init(this, savedInstanceState);
              // Set our view from the "main" layout resource
              SetContentView(Resource.Layout.activity_main);
  
              /***********************************************************************/
              /**Picasso Code**/
  
              ImageView imageView = FindViewById&lt;ImageView&gt;(Resource.Id.imageView1);
              // Use the Picasso jar library to load and display this image:
              Picasso.With(this)
                  .Load("http://i.imgur.com/DvpvklR.jpg")
                  .Into(imageView);
  
              /**End Ff Picasso Code**/
              /***********************************************************************/
  
          }
          public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
          {
              Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
  
              base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
          }
      }
  }
  </code></pre>
  
  <p><strong>XML Code:</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:minWidth="25px"
      android:minHeight="25px"&gt;
      &lt;ImageView
          android:src="@drawable/icon"             &lt;!-- this line --&gt;
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:id="@+id/imageView1" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>The app does nothing, and in the emulator, the ImageView is empty.
  And there is no error, or anything.</p>
  
  <p>If you need anything more, please let me know.
  I hope you can help me, if not, thank you for your time.</p>
  
  <p>Edit 1:
  It seems, the problem lies in the C# code.
  If I add the android:src field, it still does not show up on the emulator, but when I remove the code (the Picasso code) than the image(drawable/icon) shows. Still no error!!</p>