CODEWITHSUNDEEP
androidlayoutandroid-inflate
Wolf359
Wolf359

Reputation: 2715

Newbie questtion : Inflating xml files with and without using the actually layout

This always confused me. Let's say I have these two scenarios :

First scenario : my_layout.xml:

<?xml version="1.0" encoding="utf-8"?>    
<RelativeLayout ..>
      <CardView id="@+id/myCardView" ../> // or any other view
</RelativeLayout>

In code :

.. onCreate() {
    View view = inflater.inflate(R.layout.my_layout, container, false);
    myCardView = (CardView) view.findViewById(R.id.myCardView);
}

Second scenario : my_layout.xml

 <?xml version="1.0" encoding="utf-8"?> 
 <CardView ../>

In code :

.. onCreate() {
    myCardView = (CardView) inflater.inflate(R.layout.my_layout, container, false);
}

To inflate and get a CardView object, when should one use first scenario and when the second ? Note that in first scenario, I never do anything with the RelativeLayout object. It's merely used to get the CardView object.

The reason I ask is I see the first scenario in so many tutorials but it is never explained why the extra encapsulating Layout is actually there.

Is there any scenario where the first example above does make more sense than the second ?

Post Edit: Could you please evaluate my question with RecyclerView.ViewHolder pattern in mind ? Post Edit 2:

I use the first scenario in ViewHolder pattern.

public class EntryViewHolder extends RecyclerView.ViewHolder {
    public CardView cv;

    public EntryViewHolder(View itemView) {
        super(itemView);
        cv = (CardView) itemView.findViewById(R.id.entries_card_view);
    }
}

Still, even in this scenario I never make use of the encapsulating RelativeLayout. I only use it to call findViewById(..) to get the CardView object.

Upvotes: 0

Views: 40

Answers (1)

Dane Lowrey
Dane Lowrey

Reputation: 180

The first scenario would be used whenever you have an XML layout with multiple child views inside of them. A couple TextViews, EditTexts, Spinners, etc, the things you would need to put together a presentable page for the user. The <RelativeLayout and the other layout tags help organize the child views inside of them, in this case "Relative" to each other. I would stick to this practice instead of your second scenario.

I'm not sure I have ever seen anything like your second scenario before. Inflating the layout and then casting the entire layout to a CardView seems odd. The closest thing I can relate it to is when you make an XML for a custom adapter view, where you might be making a list of card objects.

Here is a helpful link on Layouts.

Upvotes: 2

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