title: Xamarin android: resource id/button_img_del (aka com.companyname.www:id/button_img_del) not found.?
body: <p>Resource.Id.button_img_del cannot be found.</p>
  <p>My layout:</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;FrameLayout
      xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
      xmlns:card_view=&quot;http://schemas.android.com/apk/res-auto&quot;
      android:layout_width=&quot;300px&quot;
      android:layout_height=&quot;400px&quot;&gt;
      &lt;android.support.v7.widget.CardView
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot;
          card_view:cardElevation=&quot;4dp&quot;
          card_view:cardUseCompatPadding=&quot;true&quot;
          card_view:cardCornerRadius=&quot;5dp&quot;&gt;
          &lt;LinearLayout
              android:layout_width=&quot;match_parent&quot;
              android:layout_height=&quot;wrap_content&quot;
              android:orientation=&quot;vertical&quot;
              android:padding=&quot;8dp&quot;&gt;
              &lt;ImageView
                  android:contentDescription=&quot;@string/app_name&quot;
                  android:src=&quot;@mipmap/ic_launcher&quot;
                  android:layout_width=&quot;match_parent&quot;
                  android:layout_height=&quot;wrap_content&quot;
                  android:id=&quot;@+id/img_item&quot;
                  android:scaleType=&quot;centerCrop&quot; /&gt;
  
              &lt;ProgressBar
                  style=&quot;?android:attr/progressBarStyleSmall&quot;
                  android:layout_width=&quot;match_parent&quot;
                  android:layout_height=&quot;wrap_content&quot;
                  android:id=&quot;@+id/progressBar1&quot; /&gt;
                  
              &lt;ImageButton
                  android:id=&quot;@id/button_img_del&quot;
                  android:scaleType=&quot;fitXY&quot;
                  android:layout_width=&quot;30dp&quot;
                  android:layout_height=&quot;30dp&quot;
                  android:cropToPadding=&quot;false&quot;
                  android:background=&quot;@drawable/ic_mtrl_chip_close_circle&quot;&gt;
  
              &lt;/ImageButton&gt;
          &lt;/LinearLayout&gt;
      &lt;/android.support.v7.widget.CardView&gt;
  &lt;/FrameLayout&gt;
  </code></pre>
  <p>Error:</p>
  <blockquote>
  <p>failed linking file resources.             resource id/button_img_del (aka
  com.companyname.www:id/button_img_del) not found.</p>
  </blockquote>
  <p>My C# code for RecyclerView.Adapter :</p>
  <pre><code>public class ImgViewHolder : RecyclerView.ViewHolder
          {
              public ProgressBar ProgressBar { get; private set; }
  
              public ImgViewHolder(View itemView) : base(itemView)
              {
                  ProgressBar = itemView.FindViewById&lt;ProgressBar&gt;(Resource.Id.progressBar1);
              }
          }
  </code></pre>
  <p>Solution?</p>