title: Setting a placeholder image in an MvxImageView control
body: <p>I have a large collection of search results bound using an MvxImageView control. As the application downloads each image there is sometimes a small wait whilst the image renders. Currently this means the search results are white before they are rendered.</p>
  
  <p>I wish to have a placeholder image in MvxImageView in the same manner that you could place one in a standard ImageView control.</p>
  
  <p>This is the code.</p>
  
  <pre><code>&lt;Mvx.MvxImageView
    android:id="@+id/item_searchresult_imageView"
    android:src="@drawable/product_placeholder"
    android:layout_gravity="center|top"
    android:layout_width="170dp"
    android:layout_height="128dp"
    android:layout_marginTop="10dp"
    android:layout_marginRight="10dp"
    android:layout_marginLeft="10dp"
    local:MvxBind="ImageUrl SearchResult.ProductImageId, Converter=PowerStorageImage" /&gt;
  </code></pre>
  
  <p>The issue is that the line</p>
  
  <pre><code> android:src="@drawable/product_placeholder"
  </code></pre>
  
  <p>doesn't seem to be set properly before the main image is loaded, and the search result is still black white prior to loading.</p>
  
  <p>Thanks</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I should also point out that in some instances there isn't actually an image for the result, and in that case I wish have the placeholder image remain.</p>