从setContentView分析layoutInflater

关于setContentView:

//把一个布局资源设置到Activity内容，这个资源将会被加载解析，添加到Activity所有顶层的的视图上。
    public void setContentView(@LayoutRes int layoutResID) {
        getWindow().setContentView(layoutResID);
        initWindowDecorActionBar();
    }

       //找到android.view.PhoneWindow类的setContentView()
    @Override
    public void setContentView(int layoutResID) {
        // Note: FEATURE_CONTENT_TRANSITIONS may be set in the process of installing the window
        // decor, when theme attributes and the like are crystalized. Do not check the feature
        // before this happens.
        if (mContentParent == null) {
            installDecor();
        } else if (!hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            mContentParent.removeAllViews();
        }

        if (hasFeature(FEATURE_CONTENT_TRANSITIONS)) {
            final Scene newScene = Scene.getSceneForLayout(mContentParent, layoutResID,
                    getContext());
            transitionTo(newScene);
        } else {
            mLayoutInflater.inflate(layoutResID, mContentParent);
        }
        mContentParent.requestApplyInsets();
        final Callback cb = getCallback();
        if (cb != null && !isDestroyed()) {
            cb.onContentChanged();
        }
        mContentParentExplicitlySet = true;
    }

// 这是窗口的顶层视图，包含窗口装饰。这里说明DecorView是窗口的顶层视图。
private DecorView mDecor;
if (mDecor == null) {
            mDecor = generateDecor(-1);
            mDecor.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
            mDecor.setIsRootNamespace(true);
            if (!mInvalidatePanelMenuPosted && mInvalidatePanelMenuFeatures != 0) {
                mDecor.postOnAnimation(mInvalidatePanelMenuRunnable);
            }
        } else {
            mDecor.setWindow(this);
        }

mLayoutInflater.inflate(layoutResID,mContentParent);逻辑代码,就是将资源文件xml进行解析然后加载到视图容器上

public View inflate(@LayoutRes int resource, @Nullable ViewGroup root) {
       return inflate(resource, root, root != null);
}

public View inflate(@LayoutRes int resource, @Nullable ViewGroup root, boolean attachToRoot) {
        final Resources res = getContext().getResources();
        if (DEBUG) {
            Log.d(TAG, "INFLATING from resource: \"" + res.getResourceName(resource) + "\" ("
                    + Integer.toHexString(resource) + ")");
        }

        final XmlResourceParser parser = res.getLayout(resource);
        try {
            return inflate(parser, root, attachToRoot);
        } finally {
            parser.close();
        }
    }

[参考](14条消息) 三个案例带你看懂LayoutInflater中inflate方法两个参数和三个参数的区别_weixin_30687051的博客-CSDN博客