Android禁止横屏竖屏切换

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
      package="com.ray.linkit" 
      android:versionCode="1" 
      android:versionName="1.0"> 
    <application android:icon="@drawable/icon" android:label="@string/app_name"> 
        <activity android:name=".Main" 
                  android:label="@string/app_name" 
                  android:screenOrientation="portrait"> 
            <intent-filter> 
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
                <activity android:name=".GamePlay" 
                android:screenOrientation="portrait"></activity> 
                <activity android:name=".OptionView" 
                android:screenOrientation="portrait"></activity> 
    </application> 
    <uses-sdk android:minSdkVersion="3" /> 
</manifest>

if(newConfig.orientation==Configuration.ORIENTATION_LANDSCAPE){
  //横向 
  setContentView(R.layout.file_list_landscape); 
}else{
  //竖向 
   setContentView(R.layout.file_list); 
}