XML布局嵌套多少层会导致OOM

查看setContentView源码可以看到，最终调用的是rInflate。
首先遍历所有的节点，假如是普通的view就直接获取，是Viewgroup的话会调用rInflateChildren，
发现在rInflateChildren里面调用的还是rInflate，是一个递归调用。
而且没有退出条件，就会导致不断地进行压栈。类似这种情况，JVM 实际会抛出 StackOverFlowError；当然，如果 JVM 试图去扩展栈空间的的时候失败，则会抛出 OutOfMemoryError。
栈最多存放多少栈帧取决于虚拟机设置的参数。

/**
     * Recursive method used to inflate internal (non-root) children. This
     * method calls through to {@link #rInflate} using the parent context as
     * the inflation context.
     * <strong>Note:</strong> Default visibility so the BridgeInflater can
     * call it.
     */
    final void rInflateChildren(XmlPullParser parser, View parent, AttributeSet attrs,
            boolean finishInflate) throws XmlPullParserException, IOException {
        rInflate(parser, parent, parent.getContext(), attrs, finishInflate);
    }

    /**
     * Recursive method used to descend down the xml hierarchy and instantiate
     * views, instantiate their children, and then call onFinishInflate().
     * <p>
     * <strong>Note:</strong> Default visibility so the BridgeInflater can
     * override it.
     */
    void rInflate(XmlPullParser parser, View parent, Context context,
            AttributeSet attrs, boolean finishInflate) throws XmlPullParserException, IOException {

        final int depth = parser.getDepth();
        int type;
        boolean pendingRequestFocus = false;

        while (((type = parser.next()) != XmlPullParser.END_TAG ||
                parser.getDepth() > depth) && type != XmlPullParser.END_DOCUMENT) {

            if (type != XmlPullParser.START_TAG) {
                continue;
            }

            final String name = parser.getName();

            if (TAG_REQUEST_FOCUS.equals(name)) {
                pendingRequestFocus = true;
                consumeChildElements(parser);
            } else if (TAG_TAG.equals(name)) {
                parseViewTag(parser, parent, attrs);
            } else if (TAG_INCLUDE.equals(name)) {
                if (parser.getDepth() == 0) {
                    throw new InflateException("<include /> cannot be the root element");
                }
                parseInclude(parser, context, parent, attrs);
            } else if (TAG_MERGE.equals(name)) {
                throw new InflateException("<merge /> must be the root element");
            } else {
                final View view = createViewFromTag(parent, name, context, attrs);
                final ViewGroup viewGroup = (ViewGroup) parent;
                final ViewGroup.LayoutParams params = viewGroup.generateLayoutParams(attrs);
                rInflateChildren(parser, view, attrs, true);
                viewGroup.addView(view, params);
            }
        }

        if (pendingRequestFocus) {
            parent.restoreDefaultFocus();
        }

        if (finishInflate) {
            parent.onFinishInflate();
        }
    }