Hello World Android Tutorial

Question

I am running the Hello World app successfully through an emulator (with Eclipse). I have followed every step from the android website. The app runs and gives me the option to enter a String and click Send. Unfortunately, when I click send, nothing happens. I have completed this app through the tutorial, and I have tried setting the message to something within the code, but no success. It is my best guess that DisplayMessageActivity.java is not running, because I have tried giving the message to be displayed a preset String, but have not been successful. I know this is a fairly vague question, but I cannot seem to find the next step to solve this problem, hence the question. Thanks! Let me know if you need to see any additional code; here is my code for MainActivity.java:

package com.example.myfirstapp;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
 public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 }
// @Override
// public boolean onCreateOptionsMenu(Menu menu) {
// // Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.activity_main, menu);
// return true;
// }
 //** Called when the user clicks the Send button *
 public void sendMessage(View view){
 //Do something in response to the button
 Intent intent = new Intent(this, DisplayMessageActivity.class);
 EditText editText = (EditText) findViewById(R.id.edit_message);
 String message = editText.getText().toString();
 intent.putExtra(EXTRA_MESSAGE, message);
 }
}

Answer 1

You need to call startActivity (intent); from your sendMessage(). Put it right before the closing brace.

• Evorlor: Got it. Thanks. It has been accepted!And if you don't mind me asking, what exactly is startActivity(intent); doing? I would like to put a comment above it that I can refer to later as needed.
• Pavlos: It starts your new Activity as the name states. Meaning that when that piece of code is executed it will send you to the class pointed by the Intent!