如何设置微调器的适配器

Question

how to set adapter to spinner if i have ArrayList<HashMap<String, String>> coursesList that contine information that i will display it

what is the correct type of adapter that i should use

Answer 1

ArrayAdapter should work. Try with a string[].

Spinner s = null;
final String[] choices = {"1","2"};
ArrayAdapter<String> a =new ArrayAdapter<String>(ObservationSubmit.this,android.R.layout.simple_spinner_item, choices);
a.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s.setAdapter(a); 

Answer 2

 String[] arraySpinner = new String[] {
            "1", "2", "3", "4", "5", "6", "7"
        };  
  Spinner s = (Spinner) findViewById(R.id.Spinner01);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, arraySpinner);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        s.setAdapter(adapter);

Answer 3

import android.content.Context;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import com.agreeta.firebasedatabasedemo.R;

import java.util.ArrayList;
import java.util.HashMap;

public class TestAdapter extends ArrayAdapter {

    private Context mContext;
    private ArrayList<HashMap<String, String>> hashMapArrayList = new ArrayList<>();

    public TestAdapter(@NonNull Context context, ArrayList<HashMap<String, String>> list) {
        super(context, 0 , list);
        mContext = context;
        hashMapArrayList = list;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        View listItem = convertView;
        if(listItem == null)
            listItem = LayoutInflater.from(mContext).inflate(R.layout.like_row,parent,false);

        TextView release = (TextView) listItem.findViewById(R.id.tv_title);
        release.setText(hashMapArrayList.get(position).get("key"));



        return listItem;
    }
}

Try with this example. Here "key" is your HashMap key by which you can set value to row of spinner.