CODEWITHSUNDEEP
android
Chirag
Chirag

Reputation: 1

What's the difference between array adapter & android.entries in spinner?

What difference does it make, if I assign some items using an ArrayAdapter or using android:entries?
Which drawbacks will I face, related to a Spinner functionality?

Adding elements using android:entries

<Spinner
            android:id="@+id/edu"
            android:layout_width="211dp"
            android:layout_height="wrap_content"
            android:layout_marginLeft="30dp"
            android:layout_marginStart="30dp"
            android:layout_marginTop="30dp"
            android:entries="@array/education"
            android:drawSelectorOnTop="true" />"

Adding the items using an ArrayAdapter:

ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getBaseContext(), android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.edu));
                        arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                        education_2.setAdapter(arrayAdapter);

Upvotes: 0

Views: 526

Answers (2)

dominicoder
dominicoder

Reputation: 10165

If you're curious how an XML attribute is used, the Android source code is your friend. You can see that Spinner extends AbsSpinner and that has a constructor defined like this:

public AbsSpinner(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    super(context, attrs, defStyleAttr, defStyleRes);
    initAbsSpinner();

    final TypedArray a = context.obtainStyledAttributes(
            attrs, R.styleable.AbsSpinner, defStyleAttr, defStyleRes);

    final CharSequence[] entries = a.getTextArray(R.styleable.AbsSpinner_entries);
    if (entries != null) {
        final ArrayAdapter<CharSequence> adapter = new ArrayAdapter<CharSequence>(
                context, R.layout.simple_spinner_item, entries);
        adapter.setDropDownViewResource(R.layout.simple_spinner_dropdown_item);
        setAdapter(adapter);
    }

    a.recycle();
}

As you can see, the code checks if the entries attribute is set and, if it is, creates a default ArrayAdapter<CharSequence>to display the given set of strings.

So, to answer your questions:

What difference it makes if I assign items using array adapter or using in build android:entries ?

If you just need to show a list of strings, there's really no difference. The entries attribute is a convenience if you simply need to display a list of strings in a default spinner view without additional customization.

What drawback I will face related to functionality of spinner?

There's no difference in functionality - it's still a spinner of strings. But you cannot customize the type of item or style of the views in the spinner. So if you need a different layout or more customization in how your items are displayed, you would write the extra code to create and set your own adapter.

Hope that helps!

Upvotes: 0

OneCricketeer
OneCricketeer

Reputation: 191738

android:entries is a static string XML list. You cannot update the Spinner content via Java code. Similarly, (maybe I forget the property, but) in the Java code you are able to use a different layout than android.R.layout.simple_list_item_1

If that's not required for your application, there's no drawback as the XML you have gets roughly translated into the same Java code.

Upvotes: 1

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