Intents

Android Intent is the message that is passed between components such as activities, content providers, broadcast receivers, services etc. It is generally used with startActivity() method to invoke activity, broadcast receivers etc. The dictionary meaning of intent is intention or purpose. So, it can be described as the intention to do action. The LabeledIntent is the subclass of android.content.Intent class.

Android intents are mainly used to:

1. Moving from one Activity to other Activity
2. Passing Data inbetten Activities
3. Start Service
4. Invoke Systems service

Intents are 2 Types

Implicit

Implicit Intent doesn’t specifiy the component. In such case, intent provides information of available components provided by the system that is to be invoked.

For example, you may write the following code to view the webpage.

Intent intent=new Intent(Intent.ACTION_VIEW);   intent.setData(Uri.parse(“http://androindian.com/”));  

startActivity(intent);

activity_Main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/webView1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"   >
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/bt1"
        android:text="Implicit Intent"/>
    </LinearLayout>

MainActivity.Java

package androiindians.first;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
    Button button;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    button= (Button) findViewById(R.id.bt1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(Intent.ACTION_VIEW);
                intent.setData(Uri.parse("http://androindian.com/"));
                startActivity(intent);
            }
        });
    }
}