Hide included layout in android

Question

I have to develop an android application.

I have created one layout file that uses another layout file using the include tag.

  <include
    android:id="@+id/footer"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_alignParentBottom="true"
    layout="@layout/footer_tabs" />
  <include
    android:id="@+id/footer1"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:layout_alignParentBottom="true"
    layout="@layout/footertabs" />

I would like to show the included layout when a response is null, otherwise I would like to hide the layout and show the other. Here is what I have so far:

footertabs = (RelativeLayout) findViewById(R.id.footertab);
footer_tabs = (RelativeLayout) findViewById(R.id.footer_tab);

if (Constants.response==null) {
    footertabs.setVisibility(View.VISIBLE);
    footer_tabs.setVisibility(View.GONE);
}
else
{
    footertabs.setVisibility(View.GONE);
    footer_tabs.setVisibility(View.VISIBLE);
}

But I'm getting the following error:

07-15 17:19:09.893: E/AndroidRuntime(15143): Caused by: java.lang.NullPointerException
07-15 17:19:09.893: E/AndroidRuntime(15143):    at com.example.androidbestinuk.HomePage.onCreate(HomePage.java:56)

Please help me debug this error.

Solution 1

you should change

footertabs = (RelativeLayout) findViewById(R.id.footertab);
footer_tabs = (RelativeLayout) findViewById(R.id.footer_tab);

with

footertabs = (RelativeLayout) findViewById(R.id.footer);
footer_tabs = (RelativeLayout) findViewById(R.id.footer1);

Solution 2

Well it appears to me that you're using the wrong id's. You're getting a null pointer somewhere (I'm not sure where because there are no line numbers), but I see in your xml you have id's, footer and footer1, but in your code you are trying to find elements with id's footertab, and footer_tab. You should make these id's match.