Custom drawable not being rendered in Xamarin Studio

Issue

I am using a custom drawable to render a border around an Android TextView.

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item android:bottom="1dp" android:left="-2dp" android:right="-2dp" android:top="-10dp">
        <shape android:shape="rectangle" >
            <stroke android:width="1dp" android:color="@color/pale_grey" />
            <solid android:color="#00FFFFFF" />
            <padding android:left="24dp" android:right="24dp"
                android:top="12dp" android:bottom="12dp" />
        </shape>
    </item>
</layer-list>

This works fine at runtime but is not rendered in Xamarin Studio Designer (or the designer in Visual Studio) when viewing an Activity that has a TextView with that background applied e.g.

<TextView
    android:id="@+id/txtHeightSelection"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:clickable="true"
    android:textSize="@dimen/text_size_large"
    android:text="Height"
    android:textStyle="bold"
    android:textColor="#1f2233"
    android:background="@drawable/customborder2"
    local:MvxBind="Click AddEntryCommand, CommandParameter='Height'" />

Unsuprisingly this is a PITA as I have to Build and deploy the app just to check some simple styling. Is this a known issue?

Solution

This is a known issue that is being addressed in a coming release (flagged as 5.7):

• Bug 22243 - Android designer on XS and VS does not render Drawable shapes

As a workaround, open the drawable file in a hex editor (included in Xamarin Studio) and remove the first three bytes if they are this sequence: EF BB BF.

From Bugzilla:

The issue comes from the fact that our Android rendering process doesn't like the UTF-8 BOM sequence we forcefully add to XML files in some places.

A simple workaround is to open the drawable XML files in an editor that doesn't write a BOM and re-save the file from there. You can also open it up in an hexadecimal editor and remove the first three bytes of the file (before the initial '<').

Answered By - matthewrdev