XML : ViewPager in a Dialog not working

I am trying to implement a ViewPager inside a Dialog, I used the technique proposed here: http://stackoverflow.com/a/18710611/5482015 .The compiler does not show any error but nothing is displayed when running the app.

dialog layout xml file

      <?xml version="1.0" encoding="utf-8"?>      <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"          android:orientation="vertical" android:layout_width="200dp"          android:layout_height="200dp"          android:background="#fff"          >          <android.support.v4.view.ViewPager              android:id="@+id/pager"              android:layout_width="match_parent"              android:layout_height="match_parent">                <LinearLayout                  android:id="@+id/page_one"                  android:layout_width="match_parent"                  android:layout_height="match_parent"                  android:orientation="vertical"                  android:background="#f2a">                  <TextView                      android:text="PAGE ONE IN"                      android:layout_width="match_parent"                      android:layout_height="match_parent"                      android:textColor="#000"                      android:background="#f2a"                      android:textSize="24dp"/>              </LinearLayout>                <LinearLayout                  android:id="@+id/page_two"                  android:layout_width="match_parent"                  android:layout_height="match_parent"                  android:orientation="vertical"                  android:background="#2f1">                  <TextView                      android:text="PAGE TWO IN"                      android:layout_width="match_parent"                      android:layout_height="match_parent"                      android:textColor="#000"                      android:background="#2f1"                      android:textSize="24dp"/>              </LinearLayout>            </android.support.v4.view.ViewPager>        </LinearLayout>    

the custom dialog

   import android.app.Activity;      import android.app.Dialog;      import android.os.Bundle;      import android.view.View;      import android.view.View.OnClickListener;      import android.view.Window;      import android.widget.Button;        public class CustomDialogClass extends Dialog implements              OnClickListener {            public Activity c;          public Dialog d;              public CustomDialogClass(Activity a) {              super(a);              // TODO Auto-generated constructor stub              this.c = a;          }            @Override          protected void onCreate(Bundle savedInstanceState) {              super.onCreate(savedInstanceState);              requestWindowFeature(Window.FEATURE_NO_TITLE);              setContentView(R.layout.custom_dialog);              }              @Override          public void onClick(View v) {            }        }    

the call of the custom dialog and the adapter

   protected void onCreate(Bundle savedInstanceState) {      ...          findViewById(R.id.howto).setOnClickListener(new View.OnClickListener() {              @Override              public void onClick(View v) {                    CustomDialogClass cdd = new CustomDialogClass(mainActivity.this);                  cdd.show();                  WizardPagerAdapter adapter = new WizardPagerAdapter();                  ViewPager pager = (ViewPager)cdd. findViewById(R.id.pager);                  pager.setAdapter(adapter);                }          }    

The adapter is an inner class in mainActivity

  class WizardPagerAdapter extends PagerAdapter {            public Object instantiateItem(View collection, int position) {                int resId = 0;              switch (position) {                  case 0:                      resId = R.id.page_one;                      break;                  case 1:                      resId = R.id.page_two;                      break;              }              return findViewById(resId);          }            @Override          public int getCount() {              return 2;          }            @Override          public boolean isViewFromObject(View arg0, Object arg1) {              return arg0 == ((View) arg1);          }          @Override public void destroyItem(View arg0, int arg1, Object arg2) { }      }    

Thanking you in advance.