android - 检查 DrawableRes 是否为 VectorDrawable

Question

我有一个方法可以在 TextView 和 Button 上将 VectorDrawable 设置为 DrawableLeft、DrawableRight 等，但我想让它也适用于普通 Drawable。那么，有没有办法检查DrawableRes的类型，或者我应该使用try/catch？该方法如下所示:

public static void setViewDrawables(@NonNull View view, @DrawableRes int left, @DrawableRes int top, @DrawableRes int right, @DrawableRes int bottom) {
    final Resources resources = view.getResources();
    Drawable vectorDrawableLeft = left != 0 ? VectorDrawableCompat.create(resources, left, view.getContext().getTheme()) : null;
    Drawable vectorDrawableTop = top != 0 ? VectorDrawableCompat.create(resources, top, view.getContext().getTheme()) : null;
    Drawable vectorDrawableRight = right != 0 ? VectorDrawableCompat.create(resources, right, view.getContext().getTheme()) : null;
    Drawable vectorDrawableBottom = bottom != 0 ? VectorDrawableCompat.create(resources, bottom, view.getContext().getTheme()) : null;

    if (view instanceof Button) {
        ((Button) view).setCompoundDrawablesWithIntrinsicBounds(vectorDrawableLeft, vectorDrawableTop, vectorDrawableRight, vectorDrawableBottom);
    }
    else if (view instanceof TextView) {
        ((TextView) view).setCompoundDrawablesWithIntrinsicBounds(vectorDrawableLeft, vectorDrawableTop, vectorDrawableRight, vectorDrawableBottom);
    } else {
        Log.e("ERROR: ViewUtils", "Can't do setCompoundDrawablesWithIntrinsicBounds on " + view.getClass().getName());
    }
}

Answer 1

总结对答案的评论。据我所知，没有简单的方法可以知道 DrawableRes 是否指向 VectorDrawable。如果有人知道如何，请写下。但是要解决我的问题，按照@pskink 的建议使用 android.support.v7.content.res.AppCompatResources 就足够了。所以现在方法看起来像:

public static void setViewDrawables(@NonNull View view, @DrawableRes int left, @DrawableRes int top, @DrawableRes int right, @DrawableRes int bottom) {
    Drawable vectorDrawableLeft = left != 0 ? AppCompatResources.getDrawable(view.getContext(), left) : null;
    Drawable vectorDrawableTop = top != 0 ? AppCompatResources.getDrawable(view.getContext(), top) : null;
    Drawable vectorDrawableRight = right != 0 ? AppCompatResources.getDrawable(view.getContext(), right) : null;
    Drawable vectorDrawableBottom = bottom != 0 ? AppCompatResources.getDrawable(view.getContext(), bottom) : null;

    if (view instanceof Button) {
        ((Button) view).setCompoundDrawablesWithIntrinsicBounds(vectorDrawableLeft, vectorDrawableTop, vectorDrawableRight, vectorDrawableBottom);
    } else if (view instanceof TextView) {
        ((TextView) view).setCompoundDrawablesWithIntrinsicBounds(vectorDrawableLeft, vectorDrawableTop, vectorDrawableRight, vectorDrawableBottom);
    } else {
        Log.e("ERROR: ViewUtils", "Can't do setCompoundDrawablesWithIntrinsicBounds on " + view.getClass().getName());
    }
}

更新:

在 android.support.v7.widget.AppCompatDrawableManager 中有一个方法 boolean isVectorDrawable(@NonNull Drawable d) 检查 Drawable 是否是 VectorDrawable，但是它需要Drawable 作为参数，而不是 DrawableRes。它看起来像这样:

private static boolean isVectorDrawable(@NonNull Drawable d) {
    return d instanceof VectorDrawableCompat
          || PLATFORM_VD_CLAZZ.equals(d.getClass().getName());
}