void android.support.v4.app.Fragment.setMenuVisibility(boolean)' on a null object reference

oh yes.. i finally found my mistake.. first of all there is no mistake in my code. everything is right.

i have three tab layout and i m passing only for one tablayout and other two are getting null, so i must have to apply three switch case statement.

 public Fragment getItem(int position) {

    Fragment fragment = null;
    switch(position){
        case product_result:
            fragment = FragmentProduct.newInstance("","");
            break;
    }
    return fragment;
}

instead

  public Fragment getItem(int num) {
        Fragment fragment = null;
        switch (num) {
            case TAB_PRODUCT_RESULT:
                fragment = FragmentProduct.newInstance("", "");
                break;
            case TAB_SECOND:
                fragment = MyFragment.getInstance(num);
                break;
            case TAB_THIRD:
                fragment = MyFragment.getInstance(num);
                break;
        }
        return fragment;
    }

thats it..

I think the problem is in the public Fragment getItem(int position) method of your MyPagerAdapter. Your code snippet below is returning null fragments.

Fragment fragment = null;
switch(position){
    case product_result:
        fragment = FragmentProduct.newInstance("","");
        break;
    }
return fragment;

You only get a real fragment for the position 0, because product_result is initialized to 0. In all other cases it returns null. Modify the above snippet of code to always return a fragment instance that is not null.