This article aims to tell and show how to “Send the data from one activity to second activity using Intent”. In this example, we have two activities, activity_first which are the source activity, and activity_second which is the destination activity. We can send the data using the putExtra() method from one activity and get the data from the second activity using the getStringExtra() method.
Pre-requisites:
Example:
In this example, one EditText is used to input the text. This text is sent to the second activity when the “Send” button is clicked. For this, Intent will start and the following methods will run:
- putExtra() method is used for sending the data, data in key-value pair key is variable name and value can be Int, String, Float, etc.
- getStringExtra() method is for getting the data(key) that is sent by the above method. According to the data type of value, there are other methods like getIntExtra(), getFloatExtra()
How to Create an Android App to Send and Receive the Data between Two Activity
Step by Step Implementation
Step 1: Create a New Project in Android Studio
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. The code for that has been given in both Java and Kotlin Programming Language for Android. This will create an XML file and a Java File. Please refer to the prerequisites to learn more about this step.
Step 2: Working with the XML Files
Next, go to the activity_main.xml file, which represents the UI of the project. Below is the code for the activity_main.xml file. Comments are added inside the code to understand the code in more detail. Open the “activity_first_activity.xml” file and add the following widgets in a Relative Layout.
- An EditText to Input the message
- A Button to send the data
Also, Assign the ID to each component along with other attributes as shown in the image and the code below. The assigned ID on a component helps that component to be easily found and used in the Java/Kotlin files.
Syntax:
android:id="@+id/id_name"
Here the given IDs are as follows:
- Send Button: send_button_id
- input EditText: send_text_id
XML
<?xml version="1.0" encoding="utf-8"?> android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".first_activity"> <EditText android:id="@+id/send_text_id" android:layout_width="300dp" android:layout_height="wrap_content" android:layout_marginLeft="40dp" android:layout_marginTop="20dp" android:hint="Input" android:textSize="25dp" android:textStyle="bold" /> <Button android:id="@+id/send_button_id" android:layout_width="wrap_content" android:layout_height="40dp" android:layout_marginLeft="150dp" android:layout_marginTop="150dp" android:text="send" android:textStyle="bold" /></RelativeLayout> |
This will make the UI of the Application
Step 3: Working with the MainActivity File
Go to the MainActivity File and refer to the following code. Below is the code for the MainActivity File. Comments are added inside the code to understand the code in more detail. Now, after the UI, this step will create the Backend of the App. For this, open the “first_activity” file and instantiate the components made in the XML file (EditText, send Button) using findViewById() method. This method binds the created object to the UI Components with the help of the assigned ID.
Syntax: General
ComponentType object = (ComponentType)findViewById(R.id.IdOfTheComponent);
Syntax: for components used is as follows:
Button send_button= findViewById(R.id.send_button_id); send_text = findViewById(R.id.send_text_id);
Setting up the Operations for the Sending and Receiving of Data.
These Operations are as follows:
Add the listener to the send button and this button will send the data.
This is done as follows:
send_button.setOnClickListener(v -> {}
after clicking this button following operation will be performed. Now create the String type variable to store the value of EditText which is input by the user. Get the value and convert it to a string.
This is done as follows:
String str = send_text.getText().toString();
Now create the Intent object First_activity.java class to Second_activity class.
This is done as follows:
Intent intent = new Intent(getApplicationContext(), Second_activity.class);
where getApplicationContext() will fetch the current activity. Put the value in the putExtra method in the key-value pair then start the activity.
This is done as follows:
intent.putExtra("message_key", str);
startActivity(intent);
where “str” is the string value and the key is “message_key” this key will use to get the str value
Java
import android.content.Intent;import android.os.Bundle;import android.widget.Button;import android.widget.EditText;import androidx.appcompat.app.AppCompatActivity; public class first_activity extends AppCompatActivity { // define the variable Button send_button; EditText send_text; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_first_activity); send_button = findViewById(R.id.send_button_id); send_text = findViewById(R.id.send_text_id); // add the OnClickListener in sender button after clicked this button following Instruction will run send_button.setOnClickListener(v -> { // get the value which input by user in EditText and convert it to string String str = send_text.getText().toString(); // Create the Intent object of this class Context() to Second_activity class Intent intent = new Intent(getApplicationContext(), Second_activity.class); // now by putExtra method put the value in key, value pair key is // message_key by this key we will receive the value, and put the string intent.putExtra("message_key", str); // start the Intent startActivity(intent); }); }} |
Kotlin
import android.content.Intentimport android.os.Bundleimport android.widget.Buttonimport android.widget.EditTextimport androidx.appcompat.app.AppCompatActivity class first_activity : AppCompatActivity() { // define the variable lateinit var send_button: Button lateinit var send_text: EditText override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_first_activity) send_button = findViewById(R.id.send_button_id) send_text = findViewById(R.id.send_text_id) // add the OnClickListener in sender button after clicked this button following Instruction will run send_button.setOnClickListener { // get the value which input by user in EditText and convert it to string val str = send_text.text.toString() // Create the Intent object of this class Context() to Second_activity class val intent = Intent(applicationContext, Second_activity::class.java) // now by putExtra method put the value in key, value pair key is // message_key by this key we will receive the value, and put the string intent.putExtra("message_key", str) // start the Intent startActivity(intent) } }} |
Step 4: Creating Second_Activity to Receive the Data.
The steps to create the second activity are as follows:
android project > File > new > Activity > Empty Activity
Step 5: Working with the Second XML File
Add TextView to display the received messages. assign an ID to Textview.
XML
<?xml version="1.0" encoding="utf-8"?> android:layout_width="match_parent" android:layout_height="match_parent" tools:context="org.neveropen.navedmalik.sendthedata.Second_activity"> <TextView android:id="@+id/received_value_id" android:layout_width="300dp" android:layout_height="50dp" android:layout_marginLeft="40dp" android:layout_marginTop="20dp" android:textSize="40sp" android:textStyle="bold" android:layout_marginStart="40dp" /></RelativeLayout> |
The Second Activity is shown below:
Step 6: Working with the SecondActivity File
Define the TextView variable, use findViewById() to get the TextView as shown above.
receiver_msg = (TextView) findViewById(R.id.received_value_id);
Now In the second_activity.java file create the object of getIntent to receive the value in String type variable by the getStringExtra method using message_key.
Intent intent = getIntent();
String str = intent.getStringExtra("message_key");
The received value set in the TextView object of the second activity XML file
receiver_msg.setText(str);
Java
import android.content.Intent;import android.os.Bundle;import android.widget.TextView;import androidx.appcompat.app.AppCompatActivity; public class Second_activity extends AppCompatActivity { TextView receiver_msg; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second_activity); receiver_msg = findViewById(R.id.received_value_id); // create the get Intent object Intent intent = getIntent(); // receive the value by getStringExtra() method and // key must be same which is send by first activity String str = intent.getStringExtra("message_key"); // display the string into textView receiver_msg.setText(str); }} |
Kotlin
import android.os.Bundleimport android.widget.TextViewimport androidx.appcompat.app.AppCompatActivity class Second_activity : AppCompatActivity() { lateinit var receiver_msg: TextView override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_second_activity) receiver_msg = findViewById(R.id.received_value_id) // create the get Intent object val intent = intent // receive the value by getStringExtra() method and // key must be same which is send by first activity val str = intent.getStringExtra("message_key") // display the string into textView receiver_msg.text = str }} |
Output:
