在XML文件中使用了自定义的域名空间(ns),如app:，编译时报错XXX
XML文件类似于如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:orientation="vertical" android:id="@+id/myScrollLayout" android:layout_width="fill_parent" android:layout_height="wrap_content">
    <TextView android:layout_height="wrap_content" android:layout_width="fill_parent" android:text="Family" android:id="@+id/Family" android:textSize="16px" android:padding="5px" android:textStyle="bold" android:gravity="center_horizontal">
    </TextView>

    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" android:scrollbars="vertical">
        <LinearLayout android:orientation="vertical" android:id="@+id/myMainLayout" android:layout_width="fill_parent" android:layout_height="wrap_content">
        </LinearLayout>
    </ScrollView>

</LinearLayout>

解决方案：
增加域名空间:

A couple of reasons that this can happen: 1. You see this error with an incorrect namespace,or a typo in the attribute. Like ‘xmlns’ is wrong,it should be xmlns:android 2. First node needs to contain: xmlns:android=”http://schemas.android.com/apk/res/android” 3. If you are integrating AdMob check custom parameters like ads:adSize,you need xmlns:ads=”http://schemas.android.com/apk/lib/com.google.ads” 4. If you are using LinerLayout you might have to define tools xmlns:tools=”http://schemas.android.com/tools” xmlns:app=”http://schemas.android.com/apk/res-auto”