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Android Android Activity Lifecycle The Activity Lifecycle Saving and Retrieving Instance State

michael lee
michael lee
5,179 Points

challenge 3 0f 3

I assume that this line of code will get back an int of 10, and I can set that to the text view. But seem like it doesn't work this way, why? savedInstanceState.getString(KEY_USERENTRY)

MainActivity.java
import android.content.Intent;
import android.view.View;

public class MainActivity extends Activity {

  public TextView mTextView;
   static final String KEY_USERENTRY ="KEY_USERENTRY" ;

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

    mTextView = (TextView) findViewById(R.id.textView);
  }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
      outState.putInt(KEY_USERENTRY, 10);

    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        mTextView = setText(savedInstanceState.getString(KEY_USERENTRY));
    }
}

1 Answer

Hi Michael. there are a couple of issues with this line of code in onRestoreInstanceState():

mTextView = setText(savedInstanceState.getString(KEY_USERENTRY));
  • you need to make sure that both methods used to put the value in the Bundle and to get it out refer to the same type. Here you're calling putInt() and getString() for an integer (10).
  • remember that you call the method setText() on the object. So it should be:
mTextView.setText(...);

Finally, the method setText() takes in a String. So, as you will be getting an int from the Bundle, you will need to convert it into a String to be able to pass it in the method.

Hope that helps you complete the challenge :)

michael lee
michael lee
5,179 Points

thanks a lot!! that truly helps me and I've learned a lot

You're welcome! :)