自动完成预测后不切换活动

Question

When I enter "Joh", I get "John F. Kennedy". Now, when I click on "John F. Kennedy", it does not take me to another activity that gives info about John F. Kennedy. But I have programmed it to do so. What is wrong with my code ?

package com.mavenmaverick.autocomplete_test;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Toast;
import android.view.inputmethod.InputMethodManager;


public class MainActivity extends Activity {

String[] presidents= {
                    "John F. Kennedy",
                    "Lyndon B. Johnson",
                    "Richard Nixon",
                    "Gerald Ford",
                    "Jimmy Carter",
                    "Ronald Reagan",
                    "George H. W. Bush",
                    "Bill Clinton",
                    "George W. Bush",
                    "Barack Obama"
                    };

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView1);
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.select_dialog_item, presidents);

    textView.setThreshold(3);
    textView.setAdapter(adapter);
    textView.setOnItemSelectedListener((OnItemSelectedListener) this);
    textView.setOnItemClickListener((OnItemClickListener) this);


    textView.setOnItemSelectedListener(new OnItemSelectedListener()
    {   
    @Override
    public void onItemSelected(AdapterView<?> parent, View view,
                   int index, long id)
    {
        int position=0;
        if(position == 1){
            Intent i = new Intent (MainActivity.this, SecondActivity.class);
            startActivity(i);
            }
    }
    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub

    }
   });

    }
}

Answer 1

The main problem is the following:

@Override
public void onItemSelected(AdapterView<?> parent, View view, int index, long id)
{
    int position=0;

    // once the logic reaches this part, the value
    // of "position" will always be 0 because that 
    // is what you are setting it too. Therefore, 
    // the following if statement is skipped.
    if(position == 1) {
        Intent i = new Intent (MainActivity.this, SecondActivity.class);
        startActivity(i);
    }
}

What you want to change it too:

@Override
public void onItemSelected(AdapterView<?> parent, View view, int index, long id)
{
    if(position == 1) {
        Intent i = new Intent (MainActivity.this, SecondActivity.class);
        i.putExtra("KEY", presidents[index]);
        startActivity(i);
    }
}

The putExtra method is used to pass information between MainActivity and SecondActivity . The first parameter it takes is a String that is used as a key, and the second paramter is the actual value.

"KEY" can be any value, just remember that you will be using that same key in SecondActivity to get the value. For example:

String presidentClickedOn = getIntent().getStringExtra("KEY");