[android] How to send string from one activity to another?

I have a string in activity2

String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s", lat, lng); 

I want to insert this string into text field in activity1. How can I do that?

This question is related to android android-activity

The answer is


You can send data from one actvity to another with an Intent

Intent sendStuff = new Intent(this, TargetActivity.class);
sendStuff.putExtra(key, stringvalue);
startActivity(sendStuff);

You then can retrieve this information in the second activity by getting the intent and extracting the string extra. Do this in your onCreate() method.

Intent startingIntent = getIntent();
String whatYouSent = startingIntent.getStringExtra(key, value);

Then all you have to do is call setText on your TextView and use that string.


For those people who use Kotlin do this instead:

  1. Create a method with a parameter containing String Object.
  2. Navigate to another Activity

For Example,


// * The Method I Mentioned Above 
private fun parseTheValue(@NonNull valueYouWantToParse: String)
{
     val intent = Intent(this, AnotherActivity::class.java)
     intent.putExtra("value", valueYouWantToParse)
     intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
     startActivity(intent)
     this.finish()
}

Then just call parseTheValue("the String that you want to parse")

e.g,

val theValue: String
 parseTheValue(theValue)

then in the other activity,

val value: Bundle = intent.extras!!
// * enter the `name` from the `@param`
val str: String = value.getString("value").toString()

// * For testing
println(str)

Hope This Help, Happy Coding!

~ Kotlin Code Added By John Melody~


Intents are intense.

Intents are useful for passing data around the android framework. You can communicate with your own Activities and even other processes. Check the developer guide and if you have specific questions (it's a lot to digest up front) come back.


 Intent intent = new Intent(activity1.this, activity2.class);
 intent.putExtra("message", message);
 startActivity(intent);

In activity2, in onCreate(), you can get the String message by retrieving a Bundle (which contains all the messages sent by the calling activity) and call getString() on it :

  Bundle bundle = getIntent().getExtras();
  String message = bundle.getString("message");

Say there is EditText et1 in ur MainActivity and u wanna pass this to SecondActivity

String s=et1.getText().toString();
Bundle basket= new Bundle();
basket.putString("abc", s);
Intent a=new Intent(MainActivity.this,SecondActivity.class);
a.putExtras(basket);
startActivity(a);

now in Second Activity, say u wanna put the string passed from EditText et1 to TextView txt1 of SecondActivity

Bundle gt=getIntent().getExtras();
str=gt.getString("abc");
txt1.setText(str);

You can use the GNLauncher, which is part of a utility library I wrote in cases where a lot of interaction with the Activity is required. With the library, it is almost as simple as calling a function on the Activity object with the required parameters. https://github.com/noxiouswinter/gnlib_android/wiki#gnlauncher


In order to insert the text from activity2 to activity1, you first need to create a visit function in activity2.

public void visitactivity1()
{
    Intent i = new Intent(this, activity1.class);
    i.putExtra("key", message);
    startActivity(i);
}

After creating this function, you need to call it from your onCreate() function of activity2:

visitactivity1();

Next, go on to the activity1 Java file. In its onCreate() function, create a Bundle object, fetch the earlier message via its key through this object, and store it in a String.

    Bundle b = getIntent().getExtras();
    String message = b.getString("key", ""); // the blank String in the second parameter is the default value of this variable. In case the value from previous activity fails to be obtained, the app won't crash: instead, it'll go with the default value of an empty string

Now put this element in a TextView or EditText, or whichever layout element you prefer using the setText() function.


TWO CASES

There are two situations possible when we talk about passing data between activities.

Let's say there are two activities A and B and there is a String X. and you are in Activity A.

Now let's see the two cases

  1. A-------->B
  2. A<--------B

CASE 1:
String X is in A and you want to get it in Activity B.

It is very straightforward.

In Activity A.

1) Create Intent
2) Put Extra value
3) startActivity

Intent i = new Intent(A.this, B.class);
i.putExtra("Your_KEY",X);
startActivity(i)

In Activity B

Inside onCreate() method retrieve string X using the key which you used while storing X (Your_KEY).

Intent i = getIntent();
String s = i.getStringExtra("Your_KEY");

Case 2:
This case is little tricky if u are new to Android development Because you are in Activity A, you move to Activity B, collect the string, move back to Activity A and retrieve the collected String or data. Let's see how to deal with this situation.

In Activity A
1) Create Intent
2) start an activity with a request code.

Intent i = new Intent(A.this, B.class);
startActivityForResult(i,your_req_code);

In Activity B
1) Put string X in intent
2) Set result
3) Finish activity

Intent returnIntent = new Intent();
returnIntent .putString("KEY",X);
setResult(resCode,returnIntent);   // for the first argument, you could set Activity.RESULT_OK or your custom rescode too
finish();

Again in Activity A
1) Override onActivityResult method

onActivityResult(int req_code, int res_code, Intent data)
{
       if(req_code==your_req_code)
       {
          String X = data.getStringExtra("KEY")
       }
}

Further understanding of Case 2

You might wonder what is the reqCode, resCode in the onActivityResult(int reqCode, resCode, Intent data)

reqCode is useful when you have to identify from which activity you are getting the result from.

Let's say you have two buttons, one button starts Camera (you click a photo and get the bitmap of that image in your Activity as a result), another button starts GoogleMap( you get back the current coordinates of your location as a result). So to distinguish between the results of both activities you start CameraActivty and MapActivity with different request codes.

resCode: is useful when you have to distinguish between how results are coming back to requesting activity.

For eg: You start Camera Activity. When the camera activity starts, you could either take a photo or just move back to requesting activity without taking a photo with the back button press. So in these two situations, your camera activity sends result with different resCode ACTIVITY.RESULT_OK and ACTIVITY.RESULT_CANCEL respectively.

Relevant Links

Read more on Getting result