Unable to display item from listView on another activity

Question

I want the clicked item to be displayed in another activity.The second activity appears but the string doesn't. I tried other methods as well but the second activity just remains blank. Here is the Main Activity

EditText TxtOne;
Button btOne;
ListView lisOne;
ArrayList aL;
ArrayAdapter<String> adapt;

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

    TxtOne = (EditText) findViewById(R.id.TxtOne);
    btOne = (Button) findViewById(R.id.btOne);
    lisOne = (ListView) findViewById(R.id.lisOne);

    aL = new ArrayList<String>();
    adapt = new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_list_item_1,aL);
    lisOne.setAdapter(adapt);
    onBClick();
    lisOne.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
            Intent itemInfo = new Intent(MainActivity.this, secondActivity.class);
            itemInfo.putExtra("Itemis",position);
            startActivity(itemInfo);

        }
    });
}

public void onBClick(){
    btOne.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View v) {
            String InpItem = TxtOne.getText().toString();
            aL.add(InpItem);
            adapt.notifyDataSetChanged();
        }

    });
}

The following is the second Activity

public class secondActivity extends AppCompatActivity {
    TextView txt2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_second);

        Bundle passedData = getIntent().getExtras();
        txt2 = (TextView)findViewById(R.id.txt2);
        txt2.setText(passedData.getString("Itemis"));
    }
}

I have read other similar posts but none of them work. Some talk about the textView not being in the active layout because of which the result is NULL. The textView is in the active layout but still it doesn't display the item. Solution anyone??

Answer 1

You are passing and reading extras incorrectly. Do the following:

itemInfo.putExtra("Itemis", position); and txt2.setText(String.valueof(getIntent().getIntExtra("Itemis")));

Answer 2

In the below Listener, you are adding position to itemInfo Intent. Here position is of type int , So you should do getIntExtra() to retrieve the Integer data instead of getStringExtra()

lisOne.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
      Intent itemInfo = new Intent(MainActivity.this, secondActivity.class);
      itemInfo.putExtra("Itemis",position); //position is INT value!!
      startActivity(itemInfo);
    }
});

So you should do -

getIntExtra (String name , int defaultValue ); //this returns the int value of position.

Replace these two lines -

txt2 = (TextView)findViewById(R.id.txt2);
txt2.setText(Integer.toString(getIntent().getExtras().getIntExtra("Itemis",0))); //getting int value in second activity and converting into string for displaying

Note - you should use getStringExtra("Itemis") for retrieving string data from Intents. Not getString("Itemis") .

Refer Intent Docs Page for further details on setting and retrieving values from intents.