java - How to transfer data from one activity to another in android

Question

It might sound simple but I can't make it working. I have two activities. Which first one is a form, and second one is showing data from a JSON file based on values entered in the first activity.

So I am trying to make a simple version of it. I have a EditText, and a button, so when they press the button, whatever was in the EditText will be in the TextView of the next activity.

Here is my code so far: Main Activity

static TextView textView;

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

    textView = (TextView) findViewById(R.id.editText1);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
public void transferIT(View view){
    Intent intent = new Intent(this, Page.class);
    startActivity(intent);
}

public static String getText(){
    String data = (String) textView.getText();
    return data;
}

Main XML

<EditText
    android:id="@+id/editText1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@+id/textView1"
    android:layout_centerHorizontal="true"
    android:ems="10"
    android:hint="Enter Text to transfer" />

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="Transfer it"
    android:onClick="transferIT" />

Second Activity

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_page);
    // Show the Up button in the action bar.
    setupActionBar();


    TextView enteredValue = (TextView)findViewById(R.id.text);

    enteredValue.setText(MainActivity.getText());

}

Second XML

<TextView
    android:id="@+id/text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="58dp" />

In this way I made a method for the data of the EditText and in the other activity I call it to get access to it. Currently when I press the button it stops working. So what is your solution for having the data of the form in other activity ?

Answer 1

In first activity you should put extra argument to intent like this:

// I assume Page.class is your second ativity
Intent intent = new Intent(this, Page.class); 
intent.putExtra("arg", getText()); // getText() SHOULD NOT be static!!!
startActivity(intent);

Then in second activity you retrive argument like this:

String passedArg = getIntent().getExtras().getString("arg");
enteredValue.setText(passedArg);

It's also good to store "arg" String in MainActivity as constant and always refer to it in other places.

public static final String ARG_FROM_MAIN = "arg";