换肤入口 factory2

设置的布局入口为 setContentView，所有的setconentview最后都会执行到layoutinflate.inflate view。

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) + ")");
        }

        View view = tryInflatePrecompiled(resource, res, root, attachToRoot);
        if (view != null) {
            return view;
        }
        XmlResourceParser parser = res.getLayout(resource);
        try {
            return inflate(parser, root, attachToRoot);  //看我看我
        } finally {
            parser.close();
        }
    }

    public View inflate(XmlPullParser parser, @Nullable ViewGroup root, boolean attachToRoot) {
        synchronized (mConstructorArgs) {
            Trace.traceBegin(Trace.TRACE_TAG_VIEW, "inflate");

            final Context inflaterContext = mContext;
            final AttributeSet attrs = Xml.asAttributeSet(parser);
            Context lastContext = (Context) mConstructorArgs[0];
            mConstructorArgs[0] = inflaterContext;
            View result = root;

            try {
                advanceToRootNode(parser);
                final String name = parser.getName();

                if (TAG_MERGE.equals(name)) { //merga标签
                    if (root == null || !attachToRoot) {
                        throw new InflateException("<merge /> can be used only with a valid "
                                + "ViewGroup root and attachToRoot=true");
                    }

                    rInflate(parser, root, inflaterContext, attrs, false);
                } else {   //其他
                    final View temp = createViewFromTag(root, name, inflaterContext, attrs);//看我看我。这里去创建view根据tag
                        params = root.generateLayoutParams(attrs);
                        if (!attachToRoot) {
                            // Set the layout params for temp if we are not
                            // attaching. (If we are, we use addView, below)
                            temp.setLayoutParams(params);
                        }
                    }

           
                    rInflateChildren(parser, temp, attrs, true);

                    if (DEBUG) {
                        System.out.println("-----> done inflating children");
                    }

                    // We are supposed to attach all the views we found (int temp)
                    // to root. Do that now.
                    if (root != null && attachToRoot) {
                        root.addView(temp, params);
                    }

                    // Decide whether to return the root that was passed in or the
                    // top view found in xml.
                    if (root == null || !attachToRoot) {
                        result = temp;
                    }
                }

            } 
            return result;
        }
    }

image.png

  public final View tryCreateView(@Nullable View parent, @NonNull String name,
        @NonNull Context context,
        @NonNull AttributeSet attrs) {
        if (name.equals(TAG_1995)) {
            // Let's party like it's 1995!
            return new BlinkLayout(context, attrs);
        }

        View view;
        if (mFactory2 != null) { //重点在这里，如果设置factory2 ，那么会调用新的
            view = mFactory2.onCreateView(parent, name, context, attrs);
        } else if (mFactory != null) {
            view = mFactory.onCreateView(name, context, attrs);
        } else {
            view = null;
        }

        if (view == null && mPrivateFactory != null) {
            view = mPrivateFactory.onCreateView(parent, name, context, attrs);
        }

        return view;
    }

AppCompatDelegateImpl#createView, 返回值

image.png image.png

看，它根据标签内容，反射创建各种view

 @NonNull
    protected AppCompatTextView createTextView(Context context, AttributeSet attrs) {
        return new AppCompatTextView(context, attrs);
    }

    @NonNull
    protected AppCompatImageView createImageView(Context context, AttributeSet attrs) {
        return new AppCompatImageView(context, attrs);
    }

偷梁换柱，textview 都给你搞成AppCompatTextView。