ImageView displaying in layout but not on actual device

For me, the problem was that I was using

tools:src=...

rather than

android:src=...

It got auto-generated trying to use an already existing template image.

you can use:

android:background="@drawable/home_bar"

instead of:

android:src="@drawable/home_bar"

I had the same issue, it is only showing in Design tab for Android Studio 2.2.

What I did to make it work is to change the automatic key assigned (populated via Drag/Drop ImageView) from app:srcCompat="@drawable/logo" to android:src="@drawable/logo" in Text tab to make it appear on both the emulator and the device e.g

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/logo"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="75dp"
    android:id="@+id/logoImageView"
    android:scaleType="fitXY"
    android:scaleX="1.5"
    android:scaleY="1.5" />

Alright I've tried changing the resolution of the image (cutting it in half making it 1000x130), and somehow that fixed the problem. I think Android can't render large images like that directly? I don't know, if you know more about the subject please don't hesitate to reply! Anyway, scaling down the image worked.