Intent in Android

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           Before covering Relative layout lets discuss what is intent.

                 Intent in Android

It is interesting to know that how an activity shifts to another activity on just clicking a button, the same happens when you get a notification (when you get message on your social media apps) this all is just because of Intent. Hence, Intent is a messaging object which is used to request an action whenever you want to communicate with other activities. For example, suppose you are watching a movie on U-Tube and you get a notification on your Email when you click on that notification you will shift to that activity means that, this (E mail) activity get started and your previous activity (U-Tube) will shift onpause method.

If you want to use Intent then you have to import following you can also do this task on pressing alt + enter.

import android.content.Intent;

If you want to categories the uses of Intent then you can categories it into the followings:-

• It is used when you Start an Activity. (*Noteactivity represent a single screen )
• It is used when you Start a Service.( *Noteservice is invisible because it run on the background of an app)
• It is used when you want to deliver a broadcast. ( *Note broadcast gives us notification)

 Types of Intent:-

 To start another activity we have two methods or types:

1.Explicit Intent

2.Implicit Intent

1.Explicit Intent :-Explicit Intent is used where we know the destination path means if we want to open home page after registration in the app then in that case we know where the request will go after registration so, we will use Explicit Intent.

In the following program we are migrating from one activity to another here we will also learn how to pass data between these two activities.

// How we can pass data between two Activities.

In MainActivity.java (send data)

name=text.getText().toString();

// get the text enter in the EditText

Intent i=new Intent (getApplicationContext() ,Example.class);

// declare intent object and pass the current and destination class name.

i.putExtra("Yourname",name);

//putExtra method is used to send the data to another activity it has to parameters that are “Key” and “value” the key is then used in the destination class to fetch the value

startActivity(i);// to start the intent activity

In the second class Example.java (Fetch data)

Intent i2 = getIntent();

// to get intent make an object i2 of intent

String ur_name = i2.getStringExtra("Yourname");

// make a variable of String and pass the key within the parameters of getStringExtra

For Int or float value use getIntExtra(),getFloatExtra().

Code for Layout :-

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity"    android:orientation="vertical">
    <EditText     
   android:id="@+id/text"      
   android:hint="Enter Your Name"        
   android:layout_marginTop="3dp"     
   android:layout_width="match_parent"     
   android:layout_height="50dp"      
    />
    <Button      
    android:id="@+id/button"     
    android:layout_width="wrap_content"     
    android:layout_height="wrap_content"    
    android:layout_marginTop="20dp"       
    android:layout_gravity="center"    
    android:text="Click me"       
    android:textSize="20sp" />
</LinearLayout>

intent.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android"   
 android:orientation="vertical" 
   android:layout_width="match_parent" 
   android:layout_height="match_parent">  
  <TextView       
    android:id="@+id/name2"      
    android:layout_width="match_parent"     
    android:layout_height="118dp"      
    android:layout_gravity="center"    
    android:gravity="center"       
    android:text="TextView"    
    android:textSize="24sp" />
</LinearLayout>

Code for Java :-

MainActivity.java

package com.example.myfirstapp;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;public class MainActivity extends AppCompatActivity {
    Button click;  
    EditText text;    
    String name;   
 @Override   
 protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);  
      setContentView(R.layout.activity_main);      
      text=findViewById(R.id.text);   
      click=findViewById(R.id.button);
        click.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View v) {
               name=text.getText().toString();                Intent i  = new Intent(getApplicationContext(),Example.class);                i.putExtra("Yourname",name);                startActivity(i);                           }
        });
    }
}

Example.java

package com.example.myfirstapp;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
public class Example extends AppCompatActivity {
    TextView text2;   
 @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        
        setContentView(R.layout.intent);        
        text2=findViewById(R.id.name2);       
        Intent i2 = getIntent();        
        String ur_name = i2.getStringExtra("Yourname");     
        text2.setText("Welcome " + ur_name);
    }
}

Output :-

See the output clearly through video :-

                  

           We will discuss Implicit Intent in the next post.                        

            For any query feel free to comment.