Android TintResources Leak

　　在使用Android WebView的时候，可能会造成Activity的内存泄漏，这个是Android的Bug,目前发现在WebView内部在使用TintResources时会发生内存泄漏，但是在appcompat-v7:23.2.1中已经修复了这个问题。所以当发生WebView的Context内存泄漏时,如果泄漏引用是来自TickResources时，可以将appcompat-v7包换成23.2.1或以上就可以解决了。具体原因我们可以来下源码：

　　appcompat-v7 23.2.0 中的TintResources:

public class TintResources extends Resources {
    private final Context mContext;

    public TintResources(@NonNull final Context context, @NonNull final Resources res) {
        super(res.getAssets(), res.getDisplayMetrics(), res.getConfiguration());
        mContext = context;
    }

    /**
     * We intercept this call so that we tint the result (if applicable). This is needed for
     * things like {@link android.graphics.drawable.DrawableContainer}s which can retrieve
     * their children via this method.
     */
    @Override
    public Drawable getDrawable(int id) throws NotFoundException {
        return AppCompatDrawableManager.get().onDrawableLoadedFromResources(mContext, this, id);
    }

    final Drawable superGetDrawable(int id) {
        return super.getDrawable(id);
    }
}

appcompat-v7 23.2.1中的TintResources:

public class TintResources extends Resources {
    private final WeakReference<Context> mContextRef;

    public TintResources(@NonNull final Context context, @NonNull final Resources res) {
        super(res.getAssets(), res.getDisplayMetrics(), res.getConfiguration());
        mContextRef = new WeakReference<>(context);
    }

    /**
     * We intercept this call so that we tint the result (if applicable). This is needed for
     * things like {@link android.graphics.drawable.DrawableContainer}s which can retrieve
     * their children via this method.
     */
    @Override
    public Drawable getDrawable(int id) throws NotFoundException {
        final Context context = mContextRef.get();
        if (context != null) {
            return AppCompatDrawableManager.get().onDrawableLoadedFromResources(context, this, id);
        } else {
            return super.getDrawable(id);
        }
    }

    final Drawable superGetDrawable(int id) {
        return super.getDrawable(id);
    }
}

可以很清楚的看的23.2.1版本只是将Context的强引用改成了弱引用来避免内存泄漏。