error:ERROR parsing XML: unbound prefix in line 2

here is my code...everything should be correct though???

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com开发者_JS百科/apk/res/android"

---

In this code there is no error

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  />

But you have to set width and height of any container view. so this can be like this

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