DrawableUtils.java 文件源码

private static boolean setContainerConstantStateV7(DrawableContainer drawable, ConstantState constantState) {
    if (!sDrawableContainerStateFieldFetched) {
        try {
            sDrawableContainerStateField = DrawableContainer.class.getDeclaredField("mDrawableContainerStateField");
            sDrawableContainerStateField.setAccessible(true);
        } catch (NoSuchFieldException e) {
            Log.e(LOG_TAG, "Could not fetch mDrawableContainerStateField. Oh well.");
        }
        sDrawableContainerStateFieldFetched = true;
    }
    if (sDrawableContainerStateField != null) {
        try {
            sDrawableContainerStateField.set(drawable, constantState);
            return true;
        } catch (Exception e2) {
            Log.e(LOG_TAG, "Could not set mDrawableContainerStateField. Oh well.");
        }
    }
    return false;
}