Whatever you want to show needs to be within the child of the DrawerLayout. In your case, I think you would do a fragment transaction in onCreate()
to put whatever fragment you want visible first inside of the content area.
if (savedInstanceState == null) {
fragment = new OneFragment();
// Insert the fragment by replacing any existing fragment
getFragmentManager().beginTransaction()
.replace(R.id.content_frame, fragment).commit();
}
You can hold references to these fragments so you don't create a new instance of them each time the user makes a selection. You probably also want to make sure the new selection isn't the same as the current one, or else you will have extra transactions you don't need.
For opening a "new page", you want to use startActivity()
and show another activity with it's own layout. Generally speaking, don't be concerned about how long it takes an Activity to load unless you are specifically doing some meaningful work (like loading a bunch of data out of a database).
Lastly, Adapter
s are specifically for AdapterView
s (like ListView
) and are an entirely different matter. They are used in conjunction with specific UI components to generate child views for representing potentially large data sets and which can be recycled for efficiency reasons. I suggest you watch The World of ListView if you want more information/clarity about that.