Unable to set Image from Resource to Custom ImageView in Xamarin Android?

Question

I am able to set image in Non-Custom ImageView but unable to set Image in Custom ImageView , app loads successfully but unable to see the Image , below is the code.

public class MainActivity : AppCompatActivity
{


    public ImageTestView imageView;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        SetContentView(Resource.Layout.activity_main);
        imageView = FindViewById<ImageTestView>(Resource.Id.imageView1);
        imageView.SetImageResource(Resource.Mipmap.line_indent);

    }
}

<RelativeLayout 
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
   <ImageViewTestProject.ImageTestView
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:id="@+id/imageView1" />


</RelativeLayout>

public class ImageTestView : ImageView
{
    public ImageTestView(Context context,IAttributeSet attr) :
        base(context,attr)
    {

    }
}

Answer 1

Update

In the end, adding the image background through XML ended up solving the issue.

android:background="@mipmap/imagename"

---

Well I think the reason it's not working is that of the unavailable constructors and improper initialization

  public class ImageTestView : ImageView
  {
    Context mContext;
    public ImageTestView (Context context) : base(context)
    {
        init(context, null);
    }

    public ImageTestView (Context context, Android.Util.IAttributeSet attrs) : base(context, attrs)
    {
        init(context, attrs);
    }

    public ImageTestView (Context context, Android.Util.IAttributeSet attrs, int defStyleAttr) : base(context, attrs, defStyleAttr)
    {
        init(context, attrs);
    }

    public ImageTestView (Context context, Android.Util.IAttributeSet attrs, int defStyleAttr, int defStyleRes) : base(context, attrs, defStyleAttr, defStyleRes)
    {
        init(context, attrs);
    }

    private void init(Context ctx, Android.Util.IAttributeSet attrs)
    {
        mContext = ctx;
    }
  }

Then use this custom imageview in your app like:

<RelativeLayout 
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:app="http://schemas.android.com/apk/res-auto"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

 <ImageViewTestProject.ImageTestView
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:id="@+id/imageView1" />
 </RelativeLayout>

And then you can set the image resource to it like this:

    var imageView = FindViewById<ImageTestView>(Resource.Id.imageView1);
    imageView?.SetImageResource(Resource.Mipmap.line_indent);

Revert in case this does not work or in case of queries

Answer 2

1.First thing you not doing anything in custom ImageTestView class.

2.And setting the image Resource is wrong.either you have to taking from Drawable folder it should be.

imageView.SetImageResource(Resource.Drawable.line_indent);

I don't know in Xamarin Android.But if you know Android please refer this Example.it's bit similar to xamarin Android

http://www.java2s.com/Code/Android/UI/extendsImageView.htm