测试用户是否从 AutoCompleteTextView 中选择了一个项目

Question

My problem is that my code does not react accordingly whenever an user selects an item from an AutoCompleteTextView.
flag is a variable which is set to a value whenever one item from each AutoCompleteTextView has been selected. If it's set to 1, then it means it's right and it should proceed to main activity. Otherwise, a toast is displayed on click of button whose onClick calls the method callMainActivity .
There are no errors. Gradle build is successful, but clicking on that button (mentioned above) does nothing at all.
Code:

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.Toast;

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

public class Location extends AppCompatActivity {
    private static int flag=0;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_location);
    int city = android.R.layout.simple_dropdown_item_1line;
    int area = android.R.layout.simple_dropdown_item_1line;
    int store = android.R.layout.simple_dropdown_item_1line;

    String []city_array = getResources().getStringArray(R.array.City);
    String []area_array= getResources().getStringArray(R.array.Area);
    String []store_array= getResources().getStringArray(R.array.Store);

    List<String> city_list= Arrays.asList(city_array);
    List<String> area_list= Arrays.asList(area_array);
    List<String> store_list= Arrays.asList(store_array);

    ArrayAdapter<String> adapter_city = new ArrayAdapter(this,city, city_list);
    ArrayAdapter<String> adapter_area = new ArrayAdapter(this, area, area_list);
    ArrayAdapter<String> adapter_store = new ArrayAdapter(this, store, store_list);

    final AutoCompleteTextView autocompleteView_city =
            (AutoCompleteTextView) findViewById(R.id.City);
    final AutoCompleteTextView autocompleteView_area =
            (AutoCompleteTextView) findViewById(R.id.Area);
    final AutoCompleteTextView autocompleteView_store =
            (AutoCompleteTextView) findViewById(R.id.Store);

    autocompleteView_area.setAdapter(adapter_area);
    autocompleteView_city.setAdapter(adapter_city);
    autocompleteView_store.setAdapter(adapter_store);
    autocompleteView_area.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View arg0) {
            autocompleteView_area.showDropDown();
            if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
                flag=1;
            else
                flag=0;

        }
    });
    autocompleteView_city.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View arg0) {
            autocompleteView_city.showDropDown();
            if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
                flag=1;
            else
                flag=0;
        }
    });
    autocompleteView_store.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View arg0) {
            autocompleteView_store.showDropDown();
            if(autocompleteView_area.getListSelection()!= ListView.INVALID_POSITION)
                flag=1;
            else
                flag=0;
        }
    });

// This is the newly updated part

           autocompleteView_area.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick (AdapterView<?> parent, View view, int position, long id) {
            //... your stuff
            if(autocompleteView_area.getListSelection()>0) {
                flag = 1;
                System.out.println(flag + "flag at area");
            }else
                flag=0;


        }
    });

}

public void callMainActivity(View view){
    if(flag==1) {
        Intent in = new Intent(getBaseContext(), MainActivity.class);
        startActivity(in);
    }
    else
        Toast.makeText(getBaseContext(),"Please select all fields properly",Toast.LENGTH_LONG);
}

}

Answer 1

The reason you are not seeing the Toast or changing activities, is because you are never calling callMainActivity(View view) in your code. Add this line to the end of all your OnClickListeners : callMainActivity(arg0) -- if this does not work, put some log statements in your OnClickListeners to check if they are triggering or not.

Also, if you want to trigger the call when an item from your AutoCompleteTextView result list is selected, you should use an AdapterView.OnItemClickedListener instead. This will notify you when an item is selected from the AutoCompleteTextView list, or when nothing is selected and then you can react accordingly.