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androidandroid-drawablexml-drawable

BitmapFactory.decodeResource() returns null for shape defined in xml drawable


I looked through multiple similar questions, although I haven't found a proper answer to my issue.

I have a drawable, defined in shape.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >

    <solid android:color="@color/bg_color" />
</shape>

I want to convert it to Bitmap object in order to perform some operations, but BitmapFactory.decodeResource() returns null.

This is how I'm doing it:

Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.shape);

What am I doing wrong? Is BitmapFactory.decodeResource() applicable for xml defined drawables?


Solution

  • Since you want to load a Drawable, not a Bitmap, use this:

    Drawable d = getResources().getDrawable(R.drawable.your_drawable, your_app_theme);
    

    To turn it into a Bitmap:

    public static Bitmap drawableToBitmap (Drawable drawable) {
    
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable)drawable).getBitmap();
        }
    
        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap); 
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);
    
        return bitmap;
    }
    

    Taken from: How to convert a Drawable to a Bitmap?