<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        android:paddingBottom="@dimen/activity_vertical_margin"
        tools:context="com.droidyue.viewstubsample.MainActivity">

    <Button
            android:id="@+id/clickMe"
            android:text="Hello World!"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    
    <ViewStub
            android:id="@+id/myViewStub"
            android:inflatedId="@+id/myInflatedViewId"
            android:layout="@layout/include_merge"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/clickMe"
    />
</RelativeLayout>

ViewStub myViewStub = (ViewStub)findViewById(R.id.myViewStub);
if (myViewStub != null) {
    myViewStub.inflate();
    //或者是下面的形式加载
    //myViewStub.setVisibility(View.VISIBLE);
}

<merge xmlns:android="http://schemas.android.com/apk/res/android">

    <Button
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Yes"/>

    <Button
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="No"/>

</merge>

 E AndroidRuntime: android.view.InflateException: Binary XML file line #1: <merge /> can be used only with a valid ViewGroup root and attachToRoot=true
 E AndroidRuntime:         at android.view.LayoutInflater.inflate(LayoutInflater.java:551)
 E AndroidRuntime:         at android.view.LayoutInflater.inflate(LayoutInflater.java:429)
 E AndroidRuntime:         at android.view.ViewStub.inflate(ViewStub.java:259)
 E AndroidRuntime:         at com.droidyue.viewstubsample.MainActivity$1.onClick(MainActivity.java:20)
 E AndroidRuntime:         at android.view.View.performClick(View.java:5697)
 E AndroidRuntime:         at android.widget.TextView.performClick(TextView.java:10815)
 E AndroidRuntime:         at android.view.View$PerformClick.run(View.java:22526)
 E AndroidRuntime:         at android.os.Handler.handleCallback(Handler.java:739)
 E AndroidRuntime:         at android.os.Handler.dispatchMessage(Handler.java:95)
 E AndroidRuntime:         at android.os.Looper.loop(Looper.java:158)
 E AndroidRuntime:         at android.app.ActivityThread.main(ActivityThread.java:7237)
 E AndroidRuntime:         at java.lang.reflect.Method.invoke(Native Method)
 E AndroidRuntime:         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
 E AndroidRuntime:         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
 E AndroidRuntime: Caused by: android.view.InflateException: <merge /> can be used only with a valid ViewGroup root and attachToRoot=true
 E AndroidRuntime:         at android.view.LayoutInflater.inflate(LayoutInflater.java:491)
 E AndroidRuntime:         ... 13 more

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
        <include layout="@layout/merge_layout"/>
</LinearLayout>

/**
     * When visibility is set to {@link #VISIBLE} or {@link #INVISIBLE},
     * {@link #inflate()} is invoked and this StubbedView is replaced in its parent
     * by the inflated layout resource.
     *
     * @param visibility One of {@link #VISIBLE}, {@link #INVISIBLE}, or {@link #GONE}.
     *
     * @see #inflate() 
     */
    @Override
    public void setVisibility(int visibility) {
        if (mInflatedViewRef != null) {
            View view = mInflatedViewRef.get();
            if (view != null) {
                view.setVisibility(visibility);
            } else {
                throw new IllegalStateException("setVisibility called on un-referenced view");
            }
        } else {
            super.setVisibility(visibility);
            if (visibility == VISIBLE || visibility == INVISIBLE) {
                inflate();
            }
        }
    }

/**
     * Inflates the layout resource identified by {@link #getLayoutResource()}
     * and replaces this StubbedView in its parent by the inflated layout resource.
     *
     * @return The inflated layout resource.
     *
     */
    public View inflate() {
        final ViewParent viewParent = getParent();

        if (viewParent != null && viewParent instanceof ViewGroup) {
            if (mLayoutResource != 0) {
                final ViewGroup parent = (ViewGroup) viewParent;
                final LayoutInflater factory = LayoutInflater.from(mContext);
                final View view = factory.inflate(mLayoutResource, parent,
                        false);

                if (mInflatedId != NO_ID) {
                    view.setId(mInflatedId);
                }

                final int index = parent.indexOfChild(this);
                parent.removeViewInLayout(this);

                final ViewGroup.LayoutParams layoutParams = getLayoutParams();
                if (layoutParams != null) {
                    parent.addView(view, index, layoutParams);
                } else {
                    parent.addView(view, index);
                }

                mInflatedViewRef = new WeakReference<View>(view);

                if (mInflateListener != null) {
                    mInflateListener.onInflate(this, view);
                }

                return view;
            } else {
                throw new IllegalArgumentException("ViewStub must have a valid layoutResource");
            }
        } else {
            throw new IllegalStateException("ViewStub must have a non-null ViewGroup viewParent");
        }
    }