In this tip i show you how we can select multiple item inside a spinner using checkbox in android. With the help of MultiSelectionSpinner class.

Multiselect spinner

MultiSelectionSpinner
Step 1. First add this class in your project which help you to achieve multiselect feature in your spinner.

package com.mutiselect;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnMultiChoiceClickListener;
import android.util.AttributeSet;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.SpinnerAdapter;

import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;

/**
 * Created by Aneh Thakur on 5/7/2015.
 */
public class MultiSelectionSpinner extends Spinner implements
        OnMultiChoiceClickListener {
    String[] _items = null;
    boolean[] mSelection = null;

    ArrayAdapter<String> simple_adapter;

    public MultiSelectionSpinner(Context context) {
        super(context);

        simple_adapter = new ArrayAdapter<String>(context,
                android.R.layout.simple_spinner_item);
        super.setAdapter(simple_adapter);
    }

    public MultiSelectionSpinner(Context context, AttributeSet attrs) {
        super(context, attrs);

        simple_adapter = new ArrayAdapter<String>(context,
                android.R.layout.simple_spinner_item);
        super.setAdapter(simple_adapter);
    }

    public void onClick(DialogInterface dialog, int which, boolean isChecked) {
        if (mSelection != null && which < mSelection.length) {
            mSelection[which] = isChecked;

            simple_adapter.clear();
            simple_adapter.add(buildSelectedItemString());
        } else {
            throw new IllegalArgumentException(
                    "Argument 'which' is out of bounds.");
        }
    }

    @Override
    public boolean performClick() {
        AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
        builder.setMultiChoiceItems(_items, mSelection, this);
        builder.show();
        return true;
    }

    @Override
    public void setAdapter(SpinnerAdapter adapter) {
        throw new RuntimeException(
                "setAdapter is not supported by MultiSelectSpinner.");
    }

    public void setItems(String[] items) {
        _items = items;
        mSelection = new boolean[_items.length];
        simple_adapter.clear();
        simple_adapter.add(_items[0]);
        Arrays.fill(mSelection, false);
    }

    public void setItems(List<String> items) {
        _items = items.toArray(new String[items.size()]);
        mSelection = new boolean[_items.length];
        simple_adapter.clear();
        simple_adapter.add(_items[0]);
        Arrays.fill(mSelection, false);
    }

    public void setSelection(String[] selection) {
        for (String cell : selection) {
            for (int j = 0; j < _items.length; ++j) {
                if (_items[j].equals(cell)) {
                    mSelection[j] = true;
                }
            }
        }
    }

    public void setSelection(List<String> selection) {
        for (int i = 0; i < mSelection.length; i++) {
            mSelection[i] = false;
        }
        for (String sel : selection) {
            for (int j = 0; j < _items.length; ++j) {
                if (_items[j].equals(sel)) {
                    mSelection[j] = true;
                }
            }
        }
        simple_adapter.clear();
        simple_adapter.add(buildSelectedItemString());
    }

    public void setSelection(int index) {
        for (int i = 0; i < mSelection.length; i++) {
            mSelection[i] = false;
        }
        if (index >= 0 && index < mSelection.length) {
            mSelection[index] = true;
        } else {
            throw new IllegalArgumentException("Index " + index
                    + " is out of bounds.");
        }
        simple_adapter.clear();
        simple_adapter.add(buildSelectedItemString());
    }

    public void setSelection(int[] selectedIndicies) {
        for (int i = 0; i < mSelection.length; i++) {
            mSelection[i] = false;
        }
        for (int index : selectedIndicies) {
            if (index >= 0 && index < mSelection.length) {
                mSelection[index] = true;
            } else {
                throw new IllegalArgumentException("Index " + index
                        + " is out of bounds.");
            }
        }
        simple_adapter.clear();
        simple_adapter.add(buildSelectedItemString());
    }

    public List<String> getSelectedStrings() {
        List<String> selection = new LinkedList<String>();
        for (int i = 0; i < _items.length; ++i) {
            if (mSelection[i]) {
                selection.add(_items[i]);
            }
        }
        return selection;
    }

    public List<Integer> getSelectedIndicies() {
        List<Integer> selection = new LinkedList<Integer>();
        for (int i = 0; i < _items.length; ++i) {
            if (mSelection[i]) {
                selection.add(i);
            }
        }
        return selection;
    }

    private String buildSelectedItemString() {
        StringBuilder sb = new StringBuilder();
        boolean foundOne = false;

        for (int i = 0; i < _items.length; ++i) {
            if (mSelection[i]) {
                if (foundOne) {
                    sb.append(", ");
                }
                foundOne = true;

                sb.append(_items[i]);
            }
        }
        return sb.toString();
    }

    public String getSelectedItemsAsString() {
        StringBuilder sb = new StringBuilder();
        boolean foundOne = false;

        for (int i = 0; i < _items.length; ++i) {
            if (mSelection[i]) {
                if (foundOne) {
                    sb.append(", ");
                }
                foundOne = true;
                sb.append(_items[i]);
            }
        }
        return sb.toString();
    }
}

Step 2. Now add view in your activity file where you want.

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <com.mutiautocomplete.MultiSelectionSpinner
        android:id="@+id/mySpinner1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/getSelected"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Check"/>

</LinearLayout>

Step3. Now open your MainActivity.java file in which you want to get you selected item.

package com.mutiselect;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;


import java.util.ArrayList;


public class MainActivity extends ActionBarActivity {

    MultiSelectionSpinner spinner;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
        // Multi spinner
        spinner = (MultiSelectionSpinner) findViewById(R.id.getSelected);

        Button bt = (Button) findViewById(R.id.btn);
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String s = spinner.getSelectedItemsAsString();
                Log.e("getSelected", s);
            }
        });

    }
}

Hope this code help you.

happy coading 🙂