I tried to set a full screen background for my main layout in android studio 2.3.3.

But the problem is
even when I convert my image for all the dpi's but stay cant see my image in my background
i use (android:background="Drawble/bg-main" ) not working
i use ImageView to set it but its not working and show this error (failed to instantiate one or more class)

I don't know what to do and I am very newbie in android developing thanks for helping me
see my screen shot to understand completely

**Screen Shot Error 1:**

[![enter image description here](https://i.stack.imgur.com/bP6zL.png)](https://i.stack.imgur.com/bP6zL.png)

**Screen Shot Error 2:**

[![enter image description here](https://i.stack.imgur.com/jBdRV.png)](https://i.stack.imgur.com/jBdRV.png)