下拉列表spinner

package s.jf3q.spinner;

import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
    Spinner sp;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String[] array=new String[]{"1","2","3"};

          sp=findViewById(R.id.sp);
        ArrayAdapter<String> aa=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,array);
        aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);



        sp.setAdapter(aa);










        sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String s=parent.getItemAtPosition(position).toString();
                Toast.makeText(MainActivity.this,s,Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });






    }
}

array.xml放在values下

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="ctype">
        <item>1</item>
        <item>23</item>
        <item>333</item>
        <item>3333</item>
    </string-array>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

     <Spinner
             android:entries="@array/ctype"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"/>




     <Spinner
              android:id="@+id/sp"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"/>

</LinearLayout>